CA6-BASED REFRACTORY MATERIAL WITH MEDIUM VOLUME DENSITY, PREPARATION METHOD THEREFOR, AND USE THEREOF

Abstract

Disclosed are a CA6-based thermally insulating refractory material with a medium volume density, a preparation method therefor, and the use thereof. The CA6-based thermally insulating refractory material with a medium volume density in the present invention has phases comprising CA6 and one or more selected from C2M2A14, C2M2A8, magnesium aluminate spinel, and corundum, and the refractory material has a high purity, good high temperature stability, a uniform structure, stable performance, a relatively low thermal conductivity, and good corrosion resistance to a metal, slag, etc.

Claims

1. An CA6-based thermal-insulating refractory material with medium bulk density, the phase of the thermal-insulating refractory material comprises CA6 and one or two or more selected from C2M2A14, CM2A8, magnesium aluminate spinel and corundum.

2. The thermal-insulating refractory material according to claim 1, wherein based on the mass percentage in the thermal-insulating refractory material, the total content of CA6, C2M2A14, CM2A8, magnesium aluminate spinel and corundum is ?90%, preferably 94.8-100%.

3. The thermal-insulating refractory material according to claim 1, wherein based on the mass percentage of the phase of the thermal-insulating refractory material, the phase content of CA6 is 26.7-100%, preferably 29.0-100%, more preferably 31.5-100%, still more preferably 31.5-99.5%, further preferably 38.7-99.5%; the phase content of C2M2A14 is 0-72%, preferably 0-60%; the phase content of CM2A8 is 0-72%, preferably 0-60%, further preferably 0-59.5%; the phase content of magnesium aluminate spinel is 0-10%, 0-8.0%, 0-4.60%, 0-4.0%, preferably 0; and the phase content of corundum is 0-30%, preferably 0-18%, more preferably 0-16.5%, further preferably 0-15%, most preferably 0-12%.

4. The thermal-insulating refractory material according to claim 1, wherein the chemical composition of the thermal-insulating refractory material comprises AL.sub.2O.sub.3, CaO and MgO, based on the mass percentage in the thermal-insulating refractory material, the Al.sub.2O.sub.3 is 86.65-94.10%, preferably 87.60-94.10%, 86.65-92.80%, more preferably 88.07-94.10%, 87.50-92.60%; the CaO is 5.80-8.40%, preferably 6.10-8.40%, 6.89-8.40%; and the MgO is 0-6.05%, preferably 0-5.53%, 0-5.43%, 0-5.04%.

5. The thermal-insulating refractory material according to claim 1, wherein the bulk density of the thermal-insulating refractory material is 2.40-2.90 g/cm.sup.3, preferably 2.40-2.82 g/cm.sup.3.

6. The thermal-insulating refractory material according to claim 1, wherein the phase of the matrix part of the thermal-insulating refractory material comprises CA6 and one or two or more selected from corundum, magnesium aluminate spinel, C2M2A14 and CM2A8.

7. The thermal-insulating refractory material according to claim 6, wherein based on the mass percentage of the phase of the matrix part in the thermal-insulating refractory material, the phase content of CA6 is 67.4-100%, preferably 72.5-100%, 78.2-100%, 78.8-100%; the phase content of corundum is 0-30%, preferably 0-20%, 0-25%; the phase content of magnesium aluminate spinel is 0-10%, 0-8.0%, 0-6.7%, 0-5.22%, preferably 0; the phase content of C2M2A14 is 0-30%, preferably 0-25%, 0-20%, 0-18.8%; and the phase content of CM2A8 is 0-30%, preferably 0-25%, 0-20%, 0-18.8%.

8. The thermal-insulating refractory material according to claim 6, wherein the chemical composition of the matrix part of the thermal-insulating refractory material comprises Al.sub.2O.sub.3, CaO and MgO, based on the mass percentage of the matrix part in the thermal-insulating refractory material, the Al.sub.2O.sub.3 is 89.03-94.10%, preferably 89.03-93.65%, 90.30-93.20%, 89.03-93.28%; the CaO is 5.80-8.40%, preferably 6.25-8.40%, 6.60-8.40%; and the MgO is 0-2.52%, preferably 0-2.10%, 0-1.68%.

9. The thermal-insulating refractory material according to claim 1, wherein the thermal-insulating refractory material is prepared by a method comprising the following steps: mixing a granular material and a fine powder to obtain a mixed material, then subjecting the mixed material to hot-pressed sintering to obtain the thermal-insulating refractory material.

10. The thermal-insulating refractory material according to claim 9, wherein the fine powder is one or two or more selected from the group consisting of: CaO-containing fine powder, Al.sub.2O.sub.3-containing fine powder, and MgO-containing fine powder; preferably the CaO-containing fine powder is one or two or more selected from the group consisting of: quicklime fine powder, limestone fine powder, calcium hydroxide fine powder, CaO.Math.Al.sub.2O.sub.3 fine powder, CaO.Math.2Al.sub.2O.sub.3 fine powder, 12CaO.Math.7Al.sub.2O.sub.3 fine powder, CA6 fine powder, C2M2A14 fine powder and CM2A8 fine powder; preferably the Al.sub.2O.sub.3-containing fine powder is one or two or more selected from the group consisting of: active ?-AL.sub.2O.sub.3 fine powder, ?-Al.sub.2O.sub.3 fine powder, ?-Al.sub.2O.sub.3 fine powder, aluminum hydroxide fine powder, industrial alumina fine powder, white corundum fine powder, sub-white corundum fine powder, dense corundum fine powder, sintered corundum fine powder, and tabular corundum fine powder; preferably the MgO-containing fine powder is one or two or more selected from the group consisting of: magnesite fine powder, light-calcined magnesia fine powder, brucite fine powder, magnesium hydroxide fine powder, magnesium chloride fine powder, high purity magnesia fine powder, and fused magnesia fine powder.

11. The thermal-insulating refractory material according to claim 9, wherein the granular material is one or two or more selected from the group consisting of: CA6, C2M2A14 and CM2A8, preferably CA6.

12. The thermal-insulating refractory material according to claim 9, wherein the mass ratio of the granular material to the fine powder is 0-60:40-100.

13. The thermal-insulating refractory material according to claim 2, wherein the hot-pressed sintering is performed by putting the mixed material into a mold of a high temperature device for hot-pressed sintering; or molding the mixed material at normal temperature, and then putting it into a mold of a high temperature device for hot-pressed sintering; or molding the mixed material at normal temperature, and presintering it at low temperature, and then putting it into a mold of a high temperature device for hot-pressed sintering.

14. The thermal-insulating refractory material according to claim 9, wherein the temperature of the hot-pressed sintering is 1550-1750? C.; preferably the strength of the hot-pressed sintering is 0.5-10 MPa.

15. A preparation method for thermal-insulating refractory material, comprising the following steps: mixing a granular material and a fine powder to obtain a mixed material, then subjecting the mixed material to hot-pressed sintering to obtain the thermal-insulating refractory material.

16. The preparation method according to claim 15, wherein the fine powder is one or two or more selected from the group consisting of: CaO-containing fine powder, Al.sub.2O.sub.3-containing fine powder, and MgO-containing fine powder; preferably the CaO-containing fine powder is one or two or more selected from the group consisting of: quicklime fine powder, limestone fine powder, calcium hydroxide fine powder, CaO.Math.Al.sub.2O.sub.3 fine powder, CaO.Math.2Al.sub.2O.sub.3 fine powder, 12CaO.Math.7Al.sub.2O.sub.3 fine powder, CA6 fine powder, C2M2A14 fine powder and CM2A8 fine powder; preferably the Al.sub.2O.sub.3-containing fine powder is one or two or more selected from the group consisting of: active ?-Al.sub.2O.sub.3 fine powder, ?-Al.sub.2O.sub.3 fine powder, ?-Al.sub.2O.sub.3 fine powder, aluminum hydroxide fine powder, industrial alumina fine powder, white corundum fine powder, sub-white corundum fine powder, dense corundum fine powder, sintered corundum fine powder, and tabular corundum fine powder; preferably the MgO-containing fine powder is one or two or more selected from the group consisting of: magnesite fine powder, light-calcined magnesia fine powder, brucite fine powder, magnesium hydroxide fine powder, magnesium chloride fine powder, high purity magnesia fine powder, and fused magnesia fine powder.

17. The preparation method according to claim 15, wherein the granular material is one or two or more selected from the group consisting of: CA6, C2M2A14 and CM2A8, preferably CA6.

18. The preparation method according to claim 15, wherein the mass ratio of the granular material to the fine powder is 0-60:40-100.

19. The preparation method according to claim 15, wherein the hot-pressed sintering is performed by putting the mixed material into a mold of a high temperature device for hot-pressed sintering; or molding the mixed material at normal temperature, and then putting it into a mold of a high temperature device for hot-pressed sintering; or molding the mixed material at normal temperature, and presintering it at low temperature, and then putting it into a mold of a high temperature device for hot-pressed sintering; preferably the temperature of the hot-pressed sintering is 1550-1750? C.; preferably the strength of the hot-pressed sintering is 0.5-10 MPa.

20. (canceled)

21. A permanent lining for iron and steel smelting ladles or thermal-insulating lining or working lining for an aluminum liquid ladle, wherein it comprises the thermal-insulating refractory material according to claim 1 or a thermal-insulating refractory material prepared by a preparation method comprising mixing a granular material and a fine powder to obtain a mixed material, then subjecting the mixed material to hot-pressed sintering to obtain the thermal-insulating refractory material.

22. (canceled)

Description

BRIEF DESCRIPTION OF DRAWINGS

[0110] FIG. 1 is a schematic diagram of the thermal-insulating refractory material obtained by Example 1 of the present application and the CA6 castable obtained by Comparative Example 1 after 1500? C. treatment. Wherein, Fig. A is a schematic diagram of the thermal-insulating refractory material obtained by Example 1 after 1500? C. treatment, and Fig. B is a schematic diagram of the CA6 castable obtained by Comparative Example 1 after 1500? C. treatment.

[0111] FIG. 2 is a profile diagram of the thermal-insulating refractory material obtained by Example 1 of the present application after being corroded by slag at 1500? C.

[0112] FIG. 3 is a profile diagram of CA6 castable obtained by Comparative Example 1 after being corroded by slag at 1500? C.

DETAILED DESCRIPTION OF THE INVENTION

[0113] The following is a detailed explanation of the present application in conjunction with the embodiments described in the accompanying drawings, where the same numbers in all drawings represent the same features. Although specific embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described here. On the contrary, these embodiments are provided for thoroughly understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0114] It should be noted that certain terms are used in the specification and claims to refer to specific components. It should be understood by those skilled in the art that they may use different terms to refer to the same component. This specification and claims do not use differences in nouns as a way to distinguish components, but rather use differences in the function of components as a criterion for distinguishing components. The words comprises or includes mentioned throughout the entire specification and claims are open-ended terms, they should be interpreted as including but not limited to. The subsequent description of the specification is a preferred embodiment for implementing the present application. However, the description is intended as the general principles of the specification and is not intended to limit the scope of the present application. The scope of protection of the present application shall be determined by the appended claims.

[0115] The present application provides a CA6-based thermal-insulating refractory material with medium bulk density, the phase of the thermal-insulating refractory material comprises CA6 and one or two or more selected from C2M2A14, CM2A8, magnesium aluminum spinel, and corundum.

[0116] The phase is a phase with specific physical and chemical properties in a substance.

[0117] Among them, C2M2A14 refers to 2CaO.Math.2MgO. 14Al.sub.2O.sub.3.

[0118] CM2A8 refers to CaO.Math.2MgO.Math.8Al.sub.2O.sub.3.

[0119] The phase of the thermal-insulating refractory material is determined by XRD. For example, the measured material is ground to below 325 mesh, and then scanning with an X-ray diffractometer. By analyzing the diffraction data and matching it with the standard PDF card, the relevant phases are obtained, and then the content of the relevant phases is obtained by full spectrum fitting of the diffraction data.

[0120] In a preferred embodiment of the present application, wherein based on the mass percentage in the thermal-insulating refractory material, the total content of CA6, C2M2A14, CM2A8, corundum and magnesium-aluminum spinel is ?90%, preferably 94.8-99.5%.

[0121] For example, based on the mass percentage in the thermal-insulating refractory material, the total content of CA6, C2M2A14, CM2A8, magnesium aluminum spinel, and corundum can be 90%, 91%, 92%, 93%, 94%, 95%, 96%, 96.2%, 96.55%, 96.6%, 96.8%, 97.1%, 97.5%, 97.7%, 97.8%, 97.9%, 98%, 98.05%, 98.95%, 99.15%, 100%, or any range between them.

[0122] In a preferred embodiment of the present application, wherein based on the mass percentage of the phase in the thermal-insulating refractory material, the phase content of CA6 is 26.7-100%, preferably 29.0-100%, more preferably 31.5-100%, still more preferably 31.5-99.5%, further preferably 38.7-99.5%, respectively;

[0123] The phase content of C2M2A14 is 0-72%, preferably 0-60%; [0124] the phase content of CM2A8 is 0-72%, preferably 0-60%, further preferably 0-59.5%; [0125] the phase content of magnesium alumina spinel is 0-10%, 0-8.0%, 0-4.60%, 0-4.0%, preferably 0, and [0126] the phase content of corundum is 0-30%, preferably 0-18%, more preferably 0-16.5%, further preferably 0-15%, most preferably 0-12%.

[0127] For example, based on the mass percentage of the phase in the thermal-insulating refractory material, the phase content of CA6 can be 26.7%, 28%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 97.8%, 99.5%, 100% or any range in between; [0128] the phase content of C2M2A14 can be 0, 5%, 10%, 15%, 20%, 24.5%, 25%, 30%, 35%, 35.2% 40%, 45%, 50%, 55%, 60%, 65%, 70%, 71%, 72%, or any range in between; [0129] the phase content of CM2A8 can be 0, 5%, 10%, 15%, 20%, 24%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 71%, 72% or any range in between; [0130] the phase content of corundum can be 0, 5%, 10%, 12%, 15%, 18%, 20%, 25%, 30% or any range in between; and [0131] the phase content of magnesium aluminate spinel can be 0, 1%, 2%, 3%, 4%, 4.60%, 5%, 6%, 7%, 8%, 9%, 10% or any range in between.

[0132] In a preferred embodiment of the present application, the chemical composition of the thermal-insulating refractory material comprises Al.sub.2O.sub.3, CaO and MgO, based on the mass percentage in the thermal-insulating refractory material,

[0133] The Al.sub.2O.sub.3 is 86.65-94.10%, preferably 87.60-94.10%, 86.65-92.80%, more preferably 88.07-94.10%, 87.50-92.60%;

[0134] The CaO is 5.80-8.40%, preferably 6.10-8.40%, 6.89-8.40%; and

[0135] The MgO is 0-6.05%, preferably 0-5.53%, 0-5.43%, 0-5.04%.

[0136] Based on the mass percentage in the thermal-insulating refractory material, Al.sub.2O.sub.3 can be 86.65%, 87.60%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 94.10% or any range in between;

[0137] CaO can be 5.80%, 6.0%, 7.0%, 8.0%, 8.40%, or any range in between; and

[0138] MgO can be 0, 1.0%, 2.0%, 3.0%, 4.0%, 5.0%, 5.60%, 6.05% or any range between them.

[0139] The chemical composition of the thermal-insulating refractory material is analyzed by fluorescence (XRF) and determined according to GB/T 21114-2007.

[0140] In one preferred embodiment of the present application, the bulk density of the thermal-insulating refractory is 2.40-2.90 g/cm.sup.3, preferably 2.40-2.82 g/cm.sup.3.

[0141] For example, the bulk density of the thermal-insulating refractory can be 2.40 g/cm.sup.3, 2.50 g/cm.sup.3, 2.55 g/cm.sup.3, 2.60 g/cm.sup.3, 2.70 g/cm.sup.3, 2.80 g/cm.sup.3, 2.90 g/cm.sup.3 or any range in between.

[0142] The bulk density of the thermal-insulating refractory material is determined in accordance with GB/T2997-2000.

[0143] In a preferred embodiment of the present application, the phase of the matrix part of the thermal-insulating refractory material comprises CA6 and one or two or more selected from corundum, magnesium-aluminum spinel, C2M2A14 and CM2A8.

[0144] Wherein the matrix part of the thermal-insulating refractory material refers to a part of the thermal-insulating refractory material that does not comprise granular material.

[0145] The phase of the matrix part of the thermal-insulating refractory material is determined by the micro-area diffraction using XRD.

[0146] The operation method is as follows: for example, seven different samples can be selected and seven samples can be cut from them; the micro-area diffraction of each sample is carried out, and the spectrum is full spectrum fitted to determine the content of each phase; the two data with large deviation are removed, and then the phase content of the remaining five samples is averaged to obtain the phase content of the thermal-insulating refractory material matrix. In order to ensure accurate analysis and small deviation, the selected matrix area should be maximized during sample preparation and scanning.

[0147] In a preferred embodiment of the present application, wherein based on the mass percentage of the phase of the matrix part in the thermal-insulating refractory material, the phase content of CA6 is 67.4-100%, preferably 72.5-100%, 78.2-100%, 78.8-100%; [0148] the phase content of corundum is 0-30%, preferably 0-20%, 0-25%; [0149] the phase content of magnesium aluminate spinel is 0-10%, 0-8.0%, 0-6.7%, 0-5.22%, preferably 0; [0150] the phase content of C2M2A14 is 0-30%, preferably 0-25%, 0-20%, 0-18.8%; and [0151] the phase content of CM2A8 is 0-30%, preferably 0-25%, 0-20%, 0-18.8%.

[0152] For example, based on the mass percentage of the phase of the matrix part in the thermal-insulating refractory material, the phase content of CA6 can be 67.4%, 70%, 75%, 80%, 85%, 90%, 95%, 98.5%, 100%, or any range in between; [0153] the phase content of corundum can be 0, 5%, 10%, 15%, 20%, 25%, 30% or any other country in between; [0154] the phase content of magnesium aluminate spinel can be 0, 1%, 2%, 3%, 4%, 4.85%, 5.22%, 6%, 7%, 8%, 9%, 10% or any range in between; [0155] the phase content of C2M2A14 can be 0, 5%, 10%, 15%, 20%, 25%, 30% or any range in between; and [0156] the phase content of CM2A8 can be 0, 5%, 10%, 15%, 20%, 25%, 28.4%, 30%, or any range in between.

[0157] In a preferred embodiment of the present application, the chemical composition of the matrix part of the thermal-insulating refractory comprises Al.sub.2O.sub.3, CaO and MgO, based on the mass percentage of the matrix part in the thermal-insulating refractory material, Al.sub.2O.sub.3 is 89.03-94.10%, preferably 89.03-93.65%, 90.30-93.20%, 89.03-93.28%;

[0158] CaO is 5.80-8.40%, preferably 6.25-8.40% and 6.60-8.40%; and

[0159] MgO is 0-2.52%, preferably 0-2.10% and 0-1.68%.

[0160] For example, based on the mass percentage of the matrix part in the thermal-insulating refractory material, Al.sub.2O.sub.3 can be 89.03%, 90.55%, 91.00%, 91.10%, 91.20%, 91.30%, 91.40%, 91.50%, 91.60%, 91.70%, 91.80%, 91.90%, 92.00%, 92.10%, 92.20%, 92.30%, 92 40%, 92.50%, 92.60%, 92.70%, 92.80%, 92.90%, 93.00%, 93.10%, 93.20%, 93.30%, 93.40%, 93.50%, 93.60%, 93.70%, 93.80%, 93.90%, 94.00%, 94.10% or any range in between;

[0161] CaO can be 5.80%, 5.85%, 5.90%, 6.00%, 6.10%, 6.20%, 6.30%, 6.40%, 6.50%, 6.60%, 6.70%, 6.80%, 6.90%, 7.00%, 7.10%, 7.20%, 7.30%, 7.40%, 7.50%, 7.60%, 7.70%, 7.80%, 7.90%, 8.00%, 8.10%, 8.20%, 8.30%, 8.40% or any range in between;

[0162] MgO can be 0, 1.00%, 1.10%, 1.20%, 1.30%, 1.40%, 1.48%, 1.50%, 1.60%, 1.70%, 1.80%, 1.90%, 2.00%, 2.10%, 2.20%, 2.30%, 2.52% or any range between them.

[0163] The chemical composition of the matrix part of the thermal-insulating refractory material is determined by elemental analysis, that is, EDS analysis, of the matrix part in the sample under an electron microscope.

[0164] Preferably, the method comprises the following steps: selecting 10 different samples, cutting out more than 12 samples, and surface polishing; putting each polished sample under an electron microscope to select a matrix part and an appropriate size of the rectangular area for element collection; calculating the content of the chemical composition after the element content is converted into oxide; removing the two data with large deviation, and averaging content of Al.sub.2O.sub.3, CaO and MgO of 10 samples to obtain the chemical composition of the matrix part of the thermal-insulating refractory matrix. In order to ensure the accuracy of chemical composition and small deviation, the selected rectangular area should be maximized during element collection.

[0165] In a preferred embodiment of the present application, wherein the thermal-insulating refractory is prepared by a method comprising the following steps: [0166] mixing a granular material and a fine powder to obtain a mixed material, then subjecting the mixed material to hot-pressed sintering to obtain the thermal-insulating refractory material.

[0167] The granular material refers to the part that cannot be screened through a 180 mesh square hole sieve (Xinxiang Zhongtuo Mechanical Equipment Co., LTD.), that is, the part left on the 180-mesh square hole sieve. The particle size of the granular material is 180 mesh ?8 mm.

[0168] The fine powder refers to a part through the 180 mesh square hole screen, that is, the part under the screen of the 180 mesh square hole screen, whose particle size is less than 180 mesh.

[0169] The hot-pressed sintering refers to a way to achieve material sintering under the combined action of applying pressure and temperature.

[0170] In one preferred embodiment of the present invention, the fine powder is one or two or more selected from the group consisting of: CaO-containing fine powder, Al.sub.2O.sub.3-containing fine powder, and MgO-containing fine powder; [0171] preferably, the CaO-containing fine powder is one or two or more selected from the group consisting of: quicklime, limestone, calcium hydroxide, CaO.Math.Al.sub.2O.sub.3, CaO.Math.2Al.sub.2O.sub.3(CA2), 12CaO.Math.7Al.sub.2O.sub.3(C12A7), CA6, C2M2A14 and CM2A8; [0172] preferably, the Al.sub.2O.sub.3-containing fine powder is one or two or more selected from the group consisting of: active ?-Al.sub.2O.sub.3 powder, ?-Al.sub.2O.sub.3 powder, ?-Al.sub.2O.sub.3 powder, aluminum hydroxide, industrial alumina, white corundum powder, sub-white corundum powder, dense corundum powder, sintered corundum powder and tabular corundum powder; [0173] preferably, the MgO-containing fine powder is one or two or more selected from the group consisting of: magnesite, hydroxide, light-calcined magnesia, brucite, magnesium magnesium chloride, high purity magnesia and fused magnesia; [0174] wherein the CaO containing fine powder refers to a fine powder whose chemical composition comprises CaO, or comprises CaO, and Al.sub.2O.sub.3, or comprises CaO, MgO, and Al.sub.2O.sub.3.

[0175] The Al.sub.2O.sub.3-containing fine powder refers to an alumina system fine powder whose chemical composition is mainly Al.sub.2O.sub.3.

[0176] The MgO-containing fine powder refer to a fine powder whose chemical composition is mainly MgO or Mg(OH).sub.2.

[0177] The quicklime, also known as calcined lime, is mainly composed of calcium oxide. It is usually prepared by calcining natural rocks, which are mainly composed of calcium carbonate, at high temperatures to decompose and generate carbon dioxide and calcium oxide (chemical formula: CaO, also known as quicklime, or marble).

[0178] The active ?-Al.sub.2O.sub.3 powder is an alumina powder with high activity (which is mainly ?-Al.sub.2O.sub.3), obtained by processing industrial alumina or aluminum hydroxide as a raw material at 1250-1450? C.

[0179] The ?-Al.sub.2O.sub.3 powder is an alumina powder with a higher specific surface area and better adsorption properties, obtained by treating aluminum hydroxide as a raw material at high temperatures.

[0180] The ?-Al.sub.2O.sub.3 powder is an alumina powder with a certain hydration binding properties obtained by rapid high-temperature treatment at 600-900? C. using aluminum hydroxide as the raw material.

[0181] The industrial alumina is a alumina mineral prepared from aluminum hydroxide as raw material and calcined at 900-1250? C.

[0182] The white corundum powder is an aluminum oxide raw material prepared from industrial aluminum oxide as a raw material by electric melting, with a content of over 97.5% in Al.sub.2O.sub.3. It also comprises a small amount of iron oxide, silicon oxide, and other components, and is white in color.

[0183] The sub-white corundum powder is produced from bauxite as a raw material. Because its chemical composition and physical properties are close to those of white corundum, it is called sub-white corundum. The product with the hardness of white corundum and the toughness of brown corundum, is an ideal high-grade refractory material and grinding material.

[0184] The sintered corundum powder refers to a refractory clinker made from alumina as raw material, finely ground into pellets or billets, and sintered at 1750-1900? C. It has a high bulk density, low porosity, and excellent thermal shock resistance and slag erosion resistance at high temperatures.

[0185] The tabular corundum powder has a coarsely crystallized and well-developed ?-Al2O3 crystal structure, with an Al.sub.2O.sub.3 content of over 97.0%. It has a tabular crystal structure with small pores and many closed pores.

[0186] The light-calcined magnesia is a magnesia raw material with high activity and magnesite phase, which is prepared by calcining magnesite (whose mainl component is magnesium carbonate) at 800-1000? C.

[0187] The brucite is a raw material with Mg(OH).sub.2 as its main component.

[0188] The high purity magnesia is a sintered magnesia raw material with MgO content ?96.5%, which is made from light-calcined magnesia by ball pressing and high temperature calcination.

[0189] The fused magnesia is a dense magnesia material with MgO content ?96.5%, which is prepared from light-calcined magnesia or magnesite by arc melting.

[0190] In a preferred embodiment of the present application, when using one or more fine powders containing CaO selected from the group consisting of quicklime, limestone, calcium hydroxide, CaO.Math.Al.sub.2O.sub.3, CaO.Math.2Al.sub.2O.sub.3, and 12CaO.Math.7Al.sub.2O.sub.3 (the CA6 or CMA phases or other phases cannot be formed by relying on these CaO-containing fine powders alone) as raw materials for the source of CaO components in the matrix and not satisfying the phase and chemical composition of matrix of the product, the fine powder further comprises the Al.sub.2O.sub.3-containing fine powder, or the Al.sub.2O.sub.3-containing fine powder and MgO-containing fine powder, which is determined by the the phase and chemical composition of the products.

[0191] When the MgO-containing fine powder is used(the CA6 or CMA phases or other phases cannot be formed by relying on MgO-containing fine powders alone) and if the phase and chemical composition of matrix of the product cannot be satisfied by relying on these MgO-containing fine powders alone, the fine powder further comprises the Al.sub.2O.sub.3-containing fine powder or the Al.sub.2O.sub.3-containing fine powder and CaO-containing fine powder, which is determined by the phases and chemical composition of the product.

[0192] When the Al.sub.2O.sub.3-containing fine powder is used and if the phase and chemical composition of matrix of the product cannot be satisfied by relying on these Al.sub.2O.sub.3-containing fine powders alone, the fine powder comprises the CaO-containing fine powder or the MgO-containing fine powder or the CaO-containing fine powder and MgO-containing fine powder, which is determined by the phase and chemical composition of the product.

[0193] In a preferred embodiment of the present application, wherein the granular material is one or two or more selected from the group consisting of: CA6, C2M2A14 and CM2A8, preferably CA6.

[0194] In a preferred embodiment of the present application, wherein the mass ratio of the granular material to the fine powder is 0-60:40-100.

[0195] For example, the mass ratio of the granular material to the fine powder (i.e., the granular material/the fine powder) may be 0, 1/99, 2/98, 3/97, 4/96, 5/95, 6/94, 7/93, 8/92, 9/91, 10/90, 11/89, 12/88, 13/87, 14/86, 15/85, 16/84, 17/83, 18/82, 19/81, 20/80, 21/79, 22/78, 23/77, 24/76, 25/75, 26/74, 27/73, 28/72, 29/71, 30/70, 31/69, 32/68, 33/67, 34/66, 35/65, 36/64, 37/63, 38/62, 39/61, 40/60, 41/59, 42/58, 43/57, 44/56, 45/55, 46/54, 47/53, 48/52, 49/51, 50/50, 51/49, 52/48, 53/47, 54/46, 55/45, 56/44, 57/43, 58/42, 59/41, 60/40 or any range in between.

[0196] In a preferred embodiment of the present application, the hot-pressed sintering is performed by putting the mixed material into a mold of a high temperature device for hot-pressed sintering or molding the mixed material at normal temperature and then putting it into a mold of a high temperature device for hot-pressed sintering or molding the mixed material at normal temperature, and pre-sintering it at low temperature, and then putting it into a mold of a high temperature device for hot-pressed sintering.

[0197] For example, putting the mixed material into a mold of a high temperature device for hot-pressed sintering means that the mixed material is put into a mold of a high temperature device to raise the temperature, and when the temperature rises to the highest temperature, the pressure is applied until sintering is complete; or the mixed material is put into a mold of a high temperature device to raise the temperature, and when the temperature rises to a certain temperature and the pressure is applied; then the temperature is gradually increased and the applied pressure is increased at the same time until the temperature and pressure reach the maximum to complete the hot-pressed sintering of the material; or the mixed is put into a mold of a high temperature device, The pressure applied on the mixed material is gradually increased while the temperature is increased until the temperature and pressure reach the maximum to complete the hot-pressed sintering of the material

[0198] Molding the mixed material at normal temperature, and then putting it into a mold of a high temperature device for hot-pressed sintering means that the mixed material is pressed into billets or pre-fabricated into billets at normal temperature, dried and then for hot-pressed sintering. The method of hot-pressed sintering is the same as described above.

[0199] Molding the mixed material at normal temperature, and pre-sintering it at low temperature, and then putting it into a mold of a high temperature device for hot-pressed sintering means that the mixed material is pressed or pre-molded at low temperature and pre-sintered at 1350-1500? C., and then put into a mold of a high temperature device for hot-pressed sintering.

[0200] The high temperature device is a commonly used high temperature device in this field, such as a hot press furnace.

[0201] In a preferred embodiment of the present application, the temperature of hot-press sintering is 1550-1750? C., preferably the strength of the hot-pressed sintering is 0.5-10 MPa. For example, the temperature can be 1550? C., 1600? C., 1650? C., 1700? C., 1750? C. or any range in between;

[0202] For example, the strength of the hot-pressed sintering can be 0.5 MPa, 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3 MPa, 3.5 MPa, 4 MPa, 4.5 MPa, 5 MPa, 5.5 MPa, 6 MPa, 6.5 MPa, 7 MPa, 7.5 MPa, 8 MPa, 8.5 MPa, 9 MPa, 9.5 MPa, 10 MPa, or any range in between.

[0203] The application provides a preparation method for thermal-insulating refractory material, which comprises the following steps: [0204] mixing a granular material and a fine powder to obtain a mixed material, then subjecting the mixed material to hot-pressed sintering to obtain the thermal-insulating refractory material.

[0205] In a preferred embodiment of the present application, wherein the mass ratio of the granular material to the fine powder is 0-60:40-100.

[0206] In a preferred embodiment of the present application, wherein the hot-pressed sintering is performed by [0207] putting the mixed material into a mold of a high temperature device for hot-pressed sintering; or [0208] molding the mixed material at normal temperature, and then putting it into a mold of a high temperature device for hot-pressed sintering; or [0209] molding the mixed material at normal temperature, and pre-sintering it at low temperature, and then putting it into a mold of a high temperature device for hot-pressed sintering.

[0210] In one preferred embodiment of the present application, the temperature is 1550-1750? C., preferably the strength of the hot-pressed sintering is 0.5-10 MPa.

[0211] The CA6-based thermal-insulating refractory material with medium bulk density obtained by the present application realizes good sintering of high purity CA6 system material and has high material strength. The obtained thermal-insulting refractory material has a uniform microstructure, more uniform heat insulation performance and strength, good resistance to slag and molten steel erosion ability, which is very suitable for ladle permanent lining, liquid aluminum and other thermal-insulating lining or working lining, some industrial kiln refractory material lining body, etc., with good heat insulation, heat preservation and safety, and remarkable economic and social benefits.

[0212] The present invention provides a permanent lining for iron and steel smelting ladle, which comprises the thermal-insulating refractory material mentioned above or the thermal-insulating refractory material prepared by the preparation method mentioned above.

[0213] The present application provides a thermal-insulating lining or working lining for an aluminum liquid ladle, which comprises the thermal-insulating refractory material mentioned above or the thermal-insulating refractory material prepared by the preparation method mentioned above.

Examples

[0214] The present application provides a general and/or specific description of the materials and test methods used in the test. In the examples below, unless otherwise specified, % represents wt. %, which is the mass percentage. The raw materials or instruments used are conventional raw material products which can be obtained through market if the manufacturer is not indicated. Wherein table 1 shows the quality of raw materials used in the examples.

TABLE-US-00001 TABLE 1 the quality of raw materials used in the examples. Content of Bulk Name of raw main density material component (g/cm.sup.3) Manufacturers CA6 fine powder Al.sub.2O.sub.3 ?0.8 Luzhong Refractory 90.5-92.5%, Materials Co. Ltd CaO 7.4-9.0% Tabular Al.sub.2O.sub.3 ? 97.0% ?3.50 Anmai Aluminum Co. corundum fine Ltd powder ?-Al.sub.2O.sub.3 fine Al.sub.2O.sub.3 ? 96.0% 1.10 Shandong Aluminum powder Co. Ltd Light calcined MgO ? 92.5% magnesia Limestone CaO ? 53.0% powder CA6 granule Al.sub.2O.sub.3 ?1.50 Luzhong Refractory material 90.5-92.5%, Materials Co. Ltd CaO 7.4-9.0% Industrial Al.sub.2O.sub.3 ? 96.0% Shandong Aluminum alumina fine Co. Ltd powder Fused magnesia MgO ? 96.0% ?3.45 Jiamei Refractory Materials Co. Ltd ?-Al.sub.2O.sub.3 fine Al.sub.2O.sub.3 ? 93.5% Shandong Aluminum powder Co. Ltd CM2A8 granule Al.sub.2O.sub.3 ?2.20 Luzhong Refractory material 85.0-86.5%, Materials Co. Ltd CaO 5.1-6.5%, MgO 7.8-9.0% Quicklime fine CaO ? 91.5% Jiamei Refractory powder Materials Co. Ltd High purity MgO ? 96.5% ?3.25 Jiamei Refractory magnesia Materials Co. Ltd White corundum Al.sub.2O.sub.3 ? 97.5% ?3.45 Zhengzhou Yufa Group fine powder Active ?-Al.sub.2O.sub.3 Al.sub.2O.sub.3 ? 97% Shandong Aluminum powder Co. Ltd CM2A8 fine Al.sub.2O.sub.3 ?1.50 Luzhong Refractory powder 85.0-86.5%, Materials Co. Ltd CaO 5.1-6.5%, MgO 7.8-9.0% Dense Al.sub.2O.sub.3 ? 97% ?3.85 Zhengzhou Yufa Group corundum powder 12CaO7Al.sub.2O.sub.3 Al.sub.2O.sub.3 ?2.60 Luzhong Refractory fine powder 51.0-52.0%, Materials Co. Ltd CaO 48.0-49.0% C2M2A14 Al.sub.2O.sub.3 ?2.20 Luzhong Refractory granule material 87.3-89.0%, Materials Co. Ltd CaO 6.0-7.5%, MgO 4.0-5.5% C2M2A14 Al.sub.2O.sub.3 ?1.50 Luzhong Refractory fine powder 87.3-89.0%, Materials Co. Ltd CaO 6.0-7.5%, MgO 4.0-5.5% Sub-white Al.sub.2O.sub.3 ? 96.5% ?3.75 Luoyang Jade Co. Ltd corundum powder

Example 1

[0215] (1) 500 g of CA6 granule material (the largest particle is 5 mm) and 500 g of CA6 fine powder were mixed evenly to obtain a mixed material; [0216] (2) The mixed material was put into a mold of a high temperature device for direct hot-pressed sintering. When the temperature was raised to the highest temperature of 1630? C., and the pressure of the hot-pressed sintering strength of 5 MPa was applied under this temperature, the refractory materials with medium bulk density was prepared.

[0217] The phase of the refractory material was analyzed by using XRD analysis, that is, the obtained refractory material was ground to less than 325 mesh, and then scanned by using X-ray diffractometer (Bruker: D8 Advance); by analyzing the diffraction data and matching it with the standard PDF card, the correlation phase was obtained; then, the content of the correlation phase was obtained through the full spectrum fitting of the diffraction data and the phase was mainly CA6. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 99.5%.

[0218] The chemical composition of the refractory material was analyzed by fluorescence (XRF) analysis and determined in accordance with GB/T21114-2007. Based on the mass percentage of the refractory material, the chemical composition comprised 91.04% of Al.sub.2O.sub.3 and 8.40% of CaO.

[0219] The phase analysis of the matrix part of the refractory material was measured by the micro-area diffraction using XRD, that is, 12 pieces of different refractory materials were selected and 12 samples were cut out; In each sample, the matrix region with uniform color and organizational structure was selected for micro-region diffraction, and the diffraction pattern was full spectrum fitted to determine the content of each phase; two data with large deviation were removed, and then the phase content of the remaining ten samples was averaged to obtain the phase content of the matrix part of the refractory material. The phase of the matrix part of the refractory material mainly comprised CA6, and based on the mass percentage of the phase of the matrix part of the refractory material, the phase content of the CA6 was 99.2%.

[0220] The analysis is used to determine the chemical composition of the matrix part of the refractory was measured by using EDS method, that is, 12 pieces of different refractory materials were selected, and 12 samples were cut out and surface was polished; each polished sample was put under an electron microscope to select the region with more uniform organizational structure in the matrix part, and a rectangular region with appropriate size was selected in this region for element collection; after convering the collected element contents into oxides, the chemical composition content was calculated; the two data with large deviation were removed, and then the average contents of Al.sub.2O.sub.3, CaO and MgO of the remaining 10 samples were taken as the chemical composition of the matrix part of the refractory material; based on the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised 91.20% Al.sub.2O.sub.3 and 8.40% CaO.

[0221] The CA6-based refractory material with medium bulk density was measured in accordance with GB/T2997-2000 and the bulk density was 2.54 g/cm.sup.3.

[0222] According to the standard YB/T4130-2005, the thermal conductivity of the refractory material obtained in Example 1 was 0.61 w/m.Math.k at 350? C.

[0223] The prepared material was made into a crucible, steel slag was put into the crucible. The temperature was heated to 1500? C. and kept for 3 h. Then the cooled sample is cut along the middle, and the thickness of the sample eroded by steel slag was measured to be 3.12 mm.

Example 2

[0224] (1) 400 g of CA6 granule material (the maximum particle size is 3 mm), 280 g of CA6 fine powder, 188 g of ?-Al.sub.2O.sub.3 powder, 122 g of tabular corundum powder and 23 g of Ca(OH).sub.2 fine powder were mixed evenly to obtain a mixed material; [0225] (2) the mixed material was pressed and molded at normal temperature and light-calcined at 1500? C., and then put into a mold of a high temperature device. The pressure was gradually applied since the temperature was raised to 1550? C. When the maximum temperature was raised to 1720? C., and the maximum strength of hot-pressed sintering is 1 MPa, the refractory material with medium bulk density was prepared.

[0226] The phase analysis was carried out according to the same method as Example 1, and the phase of the refractory material with medium bulk density comprised CA6 and corundum. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 is 86.50%, and the phase content of the corundum is 12%.

[0227] The chemical composition analysis was carried out according to the same method as in Example 1. Based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density obtained comprised 92.60% of Al.sub.2O.sub.3 and 6.72% of CaO.

[0228] The phase analysis of the matrix part was carried out according to the same method as in Example 1, and the phase of the matrix part of the refractory material comprised CA6 and corundum. Based on the mass percentage of the phase of the matrix part in the refractory material, the phase content of CA6 is 78.8%, and the phase content of the corundum is 20%.

[0229] The chemical composition analysis of the matrix part was carried out according to the same as in Example 1. Based on the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised 93.28% of Al.sub.2O.sub.3 and 6.60% of CaO.

[0230] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.55 g/cm.sup.3.

[0231] The analysis was carried out according to the same method as in Example 1, the thermal conductivity of the obtained refractory material was 1.02 w/m.Math.k at 350? C.

[0232] According to the same method as in Example 1, the erosion thickness of the refractory material was 2.87 mm.

Example 3

[0233] (1) 500 g of CA6 granule material (the maximum particle size is 3 mm), 400 g of CA6 fine powder and 100 g of C2M2A14 powder were mixed evenly to obtain a mixed material; [0234] (2) the mixed is put in a mold of a high temperature device for hot-pressed sintering directly. When the temperature was raised to a maximum temperature of 1630? C., and the hot-press sintering strength of 3 MPa was applied under this temperature, the refractory material with medium bulk density was prepared.

[0235] The phase analysis was carried out according to the same method as in Example 1, and the phase of the refractory material with medium bulk density comprised CA6 and C2M2A14. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 is 89.12%, and the phase content of C2M2A14 is 9.4%.

[0236] The chemical composition analysis was carried out according to the same method as in Example 1. Based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 91.03% of Al.sub.2O.sub.3, 0.43% of MgO, and 8.02% of CaO.

[0237] The phase analysis of the matrix part was carried out according to the same method as in Example 1, and the phase of the matrix part of the refractory material comprised CA6 and C2M2A14. Wherein according to the mass percentage of the phase of the matrix part in the refractory material, the phase content of CA6 was 78.2% and the phase content of C2M2A14 was 18.8%.

[0238] The chemical composition analysis of the matrix part was carried out according to the same method as in Example 1, and based on the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised 90.8% of Al.sub.2O.sub.3, 0.8% of MgO, and 8.0% of CaO.

[0239] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density wass 2.55 g/cm.sup.3.

[0240] The analysis was carried out according to the same method as in Example 1, and the thermal conductivity of the obtained refractory material was 0.95w/m.Math.k at 350? C.

[0241] According to the same method as in Example 1, the erosion thickness of the refractory material was 3.66 mm.

Example 4

[0242] (1) 500 g of CA6 granule material (the maximum particle size is 3 mm), 400 g of CA6 fine powder 85.8 g of industrial aluminum oxide powder, 8.6 g of high purity magnesia powder, and 7.8 g of calcium hydroxide powder were evenly mixed to obtain a mixed material; [0243] (2) the mixed material was put into a mold of a high temperature device for direct hot-pressed sintering. When the temperature was raised to a maximum temperature of 1650? C., and the hot-pressed sintering strength of 8 MPa was applied under this temperature, the refractory material with medium bulk density was prepared.

[0244] The phase analysis was carried out according to the same method as in Example 1, and the phase of the refractory material with medium bulk density comprised CA6 and CM2A8. Based on the mass percentage of the phase of said refractory material, the phase content of CA6 was 89.04% and the phase content of CM2A8 was 9.4%.

[0245] The chemical composition analysis was carried out according to the same method as in Example 1, and based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 90.34% of Al.sub.2O.sub.3, 0.78% of MgO and 7.86% of CaO.

[0246] The phase analysis of the matrix part was carried out according to the same method as in Example 1, and the phase of the matrix part of the refractory material comprised CA6 and CM2A8. Based on the mass percentage of the matrix part of the refractory material, the phase content of CA6 was 78.2% and the phase content of CM2A8 was 18.8%.

[0247] The chemical composition analysis of the matrix part was carried out according to the same method as in Example 1, and according to the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised of 90.30% of Al.sub.2O.sub.3, 1.68% of MgO, and 7.81% of CaO.

[0248] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.53 g/cm.sup.3.

[0249] The analysis was carried out according to the same method as in Example 1, and the thermal conductivity of the obtained refractory material was 0.96 w/m.Math.k at 350? C.

[0250] According to the same method as in Example 1, the erosion thickness of the refractory material was 3.70 mm.

Example 5

[0251] (1) 200 g of CA6 granule material (the maximum particle size is 3 mm), 200 g of C2M2A14 granule material (the maximum particle size is 3 mm), 540 g of CA6 fine powder, 4.3 g of quicklime powder, 3.05 g of fused magnesia and 54 g of white corundum fine powder were evenly mixed to obtain a mixed material; [0252] (2) the mixed was put into a mold of a high temperature device for direct hot-pressed sintering. When the temperature was raised to the temperature of 1710? C., and the hot-press sintering strength of 2 MPa was applied under this temperature, the refractory material with medium bulk density was prepared.

[0253] The phase analysis was carried out according to the same method as in Example 1, and the phase of the refractory material with medium volume comprised CA6 and CM2A8. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 71.30% and the phase content of CM2A8 was 23.5%.

[0254] The chemical composition analysis was carried out according to the same method as in Example 1, and based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 88.67% of Al.sub.2O.sub.3, 1.03% of MgO and 7.64% of CaO.

[0255] According to the same method as in Example 1, the phase analysis of the matrix part was carried out. The phase of the matrix part of the refractory material comprised CA6 and CM2A8, and based on the mass percentage of the phase of the matrix part in the refractory material, the phase content of CA6 was 87.2% and the phase content of CM2A8 was 8.3%.

[0256] The chemical composition analysis of the matrix part was carried out according to the same method as in Example 1, and based on the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised 89.03% of Al.sub.2O.sub.3, 0.35% of MgO, and 7.95% of CaO.

[0257] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.55 g/cm.sup.3.

[0258] The analysis was carried out according to the same method as in Example 1, and the thermal conductivity of the obtained refractory material was 0.84 w/m.Math.k at 350? C.

[0259] According to the same method as in Example 1, the erosion thickness of the refractory material was 3.64 mm.

Example 6

[0260] (1) 600 g of CM2A8 granule material (the maximum particle size is 3 mm), 220 g of CA6 fine powder, 176 g of dense corundum fine powder, and 15.63 g of CaCO.sub.3 fine powder were evenly mixed to obtain a mixed material; [0261] (2) the mixed material was put into a mold of a high temperature device for direct hot-pressed sintering. When the temperature was raised to a maximum temperature of 1700? C., and the hot-pressed sintering strength of 4.5 MPa was applied under this temperature, the refractory material with medium bulk density was prepared.

[0262] According to the same method as in Example 1, the phase analysis was carried out. The phase of the refractory material with medium bulk density comprises CA6, corundum and CM2A8. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 31.5%, the phase content of corundum was 7.78% and the phase content of CM2A8 was 58.4%.

[0263] The chemical composition analysis was carried out according to the same method as in Example 1, and based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 87.92% of Al.sub.2O.sub.3, 4.82% of MgO and 6.10% of CaO.

[0264] According to the same method as in Example 1, the phase analysis of the matrix part was carried out. The phase of the matrix part of the refractory material comprised CA6 and corundum. Wherein based on the mass percentage of the phase of the matrix part in the refractory material, the phase content of CA6 was 78.8% and the phase content of corundum was 20%.

[0265] The chemical composition analysis of the matrix part was carried out according to the same method as in Example 1, and based on the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised 93.28% of Al.sub.2O.sub.3, and 6.60% of CaO.

[0266] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.55 g/cm.sup.3.

[0267] The analysis was carried out according to the same method as in Example 1, the thermal conductivity of the obtained refractory material was 1.32 w/m.Math.k at 350? C.

[0268] According to the same method as in Example 1, the erosion thickness of the refractory material was 3.72 mm.

Example 7

[0269] (1) 835 g of CA6 fine powder, 60 g of tabular corundum fine powder, 110 g of ?-Al.sub.2O.sub.3 fine powder were evenly mixed to obtain a mixed material; [0270] (2) The mixture was pre-molded with water, dried and put in a mold of a high temperature device for heating. When the temperature was raised to a maximum of 1650? C., and the hot-pressed sintering strength of 6 MPa was applied at this temperature, the CA6-based refractory material with medium bulk density was prepared.

[0271] According to the same method as in Example 1, the phase analysis was carried out. The phase of the refractory material with medium bulk density comprised CA6 and corundum. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 82.0% and the phase content of corundum was 16.5%.

[0272] The chemical composition analysis was carried out according to the same method as in Example 1, and based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 91.6% of Al.sub.2O.sub.3 and 6.92% of CaO.

[0273] According to the same method as in Example 1, the phase analysis of the matrix part of the refractory material was carried out. The phase of the matrix part of the refractory material comprised CA6 and corundum. Based on the mass percentage of phase of the matrix part in the refractory material, the phase content of CA6 was 82.0% and the phase content of corundum was 16.5%.

[0274] The chemical composition analysis of the matrix part was carried out according to the same method as in Example 1, and based on the mass percentage of the phase of the matrix part in the refractory material, the chemical composition of the matrix part of the refractory material comprised 91.60% of Al.sub.2O.sub.3 and 6.92% of CaO.

[0275] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.52 g/cm.sup.3.

[0276] The analysis was carried out according to the same method as in Example 1, the thermal conductivity of the obtained refractory material was 0.9 w/m.Math.k at 350? C.

[0277] According to the same method as in Example 1, the erosion thickness of the refractory material was 4.48 mm.

Example 8

[0278] (1) 800 g of CA6 fine powder, 100 g of tabular corundum fine powder, and 105 g of ?-Al.sub.2O.sub.3 fine powder were mixed evenly to obtain a mixed material; [0279] (2) the mixed material was pre-molded with water, dried and put into a mold of a high temperature device for hot-pressed sintering. When the temperature was raised to a maximum of 1600? C., and the hot-pressed sintering strength of 8 MPa was applied at this temperature, the CA6-based refractory material with medium bulk density was prepared.

[0280] According to the same method as in Example 1, the phase analysis was carried out. The phase of the refractory material with medium bulk density comprised CA6 and corundum. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 78.6% and the phase content of corundum was 20%.

[0281] The chemical composition analysis was carried out according to the same as in Example 1, and based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 92.4% of Al.sub.2O.sub.3 and 6.52% of CaO.

[0282] According to the same method as in Example 1, the phase analysis of the matrix part was carried out. The phase of the matrix part of the refractory material comprised CA6 and corundum. Based on the mass percentage of the phase of the matrix part in the refractory material, the phase content of CA6 was 78.6% and the phase content of corundum was 20%.

[0283] The chemical composition analysis of the matrix part was carried out according to the same method as in Example 1, and based on the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised 92.4% of Al.sub.2O.sub.3 and 6.52% of CaO.

[0284] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.52 g/cm.sup.3.

[0285] The analysis was carried out according to the same method as in Example 1, the thermal conductivity of the obtained refractory material was 0.92 w/m.Math.k at 350? C.

[0286] According to the same method as in Example 1, the erosion thickness of the refractory material was 4.34 mm.

Example 9

[0287] (1) 600 g of C2M2A14 granular material (the maximum particle size is 5 mm), 85.7 g of CA6 fine powder, 308 g of aluminum hydroxide fine powder, 18.8 g of CaO fine powder and 100 g of CM2A8 fine powder were mixed evenly to obtain a mixed material; [0288] (2) the mixed material was pressed and molded at normal temperature and light-calcined at 1450? C., and then put in a mold of a high temperature device for hot-pressed sintering. When the temperature was raised to a maximum temperature of 1600? C., and the hot-pressed sintering strength of 3.8 MPa was applied at this temperature, the refractory material with medium bulk density was prepared.

[0289] The phase analysis was carried out in accordance with the same method as in Example 1, and the phase of the refractory material with medium bulk density comprised CA6, C2M2A14 and CM2A8. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 29.0%, the phase content of C2M2A14 was 60% and the phase content of CM2A8 was 8.41%.

[0290] The chemical composition analysis was carried out according to the same method as in Example 1, and based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 87.7% of Al.sub.2O.sub.3, 3.74% of MgO and 6.68% of CaO.

[0291] The phase analysis of the matrix part was carried out according to the same method as in Example 1, and the phase of the matrix part of the refractory material comprised CA6 and CM2A8. Based on the mass percentage of the phase of the refractory content, the phase content of CA6 was 72.5% and the phase content of CM2A8 was 25.0%.

[0292] The chemical composition analysis of the matrix part was carried out according to the same method as in Example 1, and based on the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised 89.03% of Al.sub.2O.sub.3, 2.10% of MgO and 7.02% of CaO.

[0293] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.55 g/cm.sup.3.

[0294] The analysis was carried out according to the same method as in Example 1, and the thermal conductivity of the obtained refractory material was 1.42 w/m.Math.k at 350? C.

[0295] According to the same method as in Example 1, the erosion thickness of the refractory material was 4.21 mm.

Example 10

[0296] (1) 600 g of CM2A8 granule material (the maximum particle size is 5 m), 200 g of CA6 fine powder, 100 g of C2M2A14 powder, 95 g of industrial alumina powder, and 8.7 g of CaO powder were mixed to obtain a mixed material; [0297] (2) the mixed material was put into a mold of a high temperature device for hot-pressed sintering directly. When the temperature was raised to a maximum temperature of 1690? C., and the hot-pressed sintering strength of 3.4 MPa was applied at this temperature, the refractory material with medium bulk density was prepared.

[0298] According to the same method as in Example 1, the phase analysis was carried out. The phase of the refractory material with medium bulk density comprised CA6, C2M2A14 and CM2A8. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 29%, the phase content of C2M2A14 was 9.07% and the phase content of CM2A8 was 60%.

[0299] The chemical composition analysis was carried out according to the same method as in Example 1, and based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 86.65% of Al.sub.2O.sub.3, 5.53% of MgO and 6.22% of CaO.

[0300] The phase analysis of the matrix part was carried out according to the same method as in Example 1, and the phase of the matrix part of the refractory material comprised CA6 and C2M2A14. Based on the mass percentage of the phase of the matrix part in the refractory material, the phase content of CA6 was 72.5% and the phase content of C2M2A14 was 25.0%.

[0301] The chemical composition analysis of the matrix part was carried out according to the same method as in Example 1, and based on the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised 89.06% of Al.sub.2O.sub.3, 1.20% of MgO and 7.64% of CaO.

[0302] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.55 g/cm.sup.3.

[0303] The analysis was carried out according to the same method as in Example 1, the thermal conductivity of the obtained refractory material was 1.48 w/m.Math.k at 350? C.

[0304] According to the same method as in Example 1, the erosion thickness of the refractory was 4.28 mm.

Example 11

[0305] (1) 600 g of CM2A8 granular material (the maximum particle size is 3 mm), 200 g of CA6 fine powder, 280.2 g of aluminum hydroxide fine powder and 22.2 g of calcium hydroxide fine powder were evenly mixed to obtain a mixed material; [0306] (2) the mixed material was pressed and molded at normal temperature and then put into a mold of a high temperature device. The pressure was gradually applied from the temperature rising at normal temperature. When the temperature was raised to a maximum temperature of 1700? C., and the maximum strength of the hot-pressed sintering was 2 MPa, the refractory material with medium bulk density was prepared.

[0307] According to the same method as in Example 1, the phase analysis of the refractory material with medium bulk density was carried out. The phase of the refractory material with medium bulk density comprised CA6 and CM2A8. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 38.7% and the phase content of CM2A8 was 59.5%.

[0308] The chemical composition analysis was carried out according to the same method as in Example 1, and based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 88.07% of Al.sub.2O.sub.3, 5.04% of MgO and 6.89% of CaO.

[0309] The phase analysis of the matrix part was carried out according to the same method as in Example 1, and the phase of the matrix part of the refractory material comprised CA6. Based on the mass percentage of the phase of the matrix part in the refractory material, the phase content of CA6 was 98.7%.

[0310] The chemical composition analysis of the matrix part was carried out according to the same method as in Example 1. Based on the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised 90.5% of Al.sub.2O.sub.3, and 8.40% of CaO.

[0311] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.65 g/cm.sup.3.

[0312] The analysis was carried out according to the same method as in Example 1, the thermal conductivity of the obtained refractory material was 1.12 w/m.Math.k at 350? C.

[0313] According to the same method as in Example 1, the erosion thickness of the refractory material was 3.67 mm.

Embodiment 12

[0314] (1) 600 g of C2M2A14 granular material (the maximum particle size is 3 mm) and 500 g of CA6 fine powder were evenly mixed to obtain a mixed material; [0315] (2) the mixed material was put into a mold of a high temperature device for hot-pressed sintering directly. When the temperature was raised to 1400? C., the pressure was gradually applied. When the temperature was raised a maximum temperature of 1720? C., and the maximum strength of the hot-pressed sintering was 10 MPa, the refractory material with medium bulk density was prepared.

[0316] According to the same method as in Example 1, the phase analysis was carried out. The phase of the refractory material with medium bulk density comprised CA6 and C2M2A14. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 38.7% and the phase content of C2M2A14 was 60%.

[0317] The chemical composition analysis was carried out according to the same method as in Example 1, and based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 89.32% of Al.sub.2O.sub.3, 2.74% of MgO and 7.41% of CaO.

[0318] The phase analysis of the matrix part was carried out according to the same method as in Example 1, and the phase of the matrix part of the refractory material comprised CA6. Based on the mass percentage of the phase of the matrix part in the refractory material, the phase content of CA6 was 100%.

[0319] The chemical composition analysis of the matrix part was carried according to the same method as in Example 1, and based on the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised 90.8% of Al.sub.2O.sub.3, and 8.40% of CaO.

[0320] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.82 g/cm.sup.3.

[0321] The analysis was carried out according to the same method as in Example 1, the thermal conductivity of the obtained refractory material was 1.55 w/m.Math.k at 350? C.

[0322] According to the same method as in Example 1, the erosion thickness of the refractory material was 3.08 mm.

Example 13

[0323] (1) 700 g of CA6 fine powder, 150 g of tabular corundum fine powder, 155 g of ?-Al.sub.2O.sub.3 fine powder and 8.7 g of CaO fine powder were evenly mixed to obtain a mixed material; [0324] (2) the mixed material was pre-molded with water, dried and put into a mold of a high temperature device for heating. When the temperature was raised to a maximum of 1550? C., and the hot-pressed sintering strength of 10 MPa was applied at this temperature, the refractory material with medium bulk density was prepared.

[0325] According to the same method as in Example 1, the phase analysis was carried out. The phase of the refractory material with medium bulk density comprised CA6 and corundum. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 67.4% and the phase content of corundum was 30%.

[0326] The chemical composition analysis was carried out according to the same method as in Example 1, and based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 94.10% of Al.sub.2O.sub.3 and 5.80% of CaO.

[0327] According to the same method as in Example 1, the phase analysis of the matrix part was carried out. The phase of the matrix part of the refractory material comprised CA6 and corundum. Based on the mass percentage of the phase of the matrix part in the refractory material, the phase content of CA6 was 67.4% and the phase content of corundum was 30%.

[0328] The chemical composition analysis of the matrix part was carried out according to the same method as in Example 1, and based on the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised 94.10% of Al.sub.2O.sub.3 and 5.80% of CaO.

[0329] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density is 2.52 g/cm.sup.3.

[0330] The analysis was carried out according to the same method as in Example 1, the thermal conductivity of the obtained refractory material was 1.02 w/m.Math.k at 350? C.

[0331] According to the same method as in Example 1, the erosion Example of the refractory material was 4.55 mm.

Example 14

[0332] (1) 600 g of CM2A8 granular material (the maximum particle size is 3 mm), 320 g of CA6 fine powder and 80 g of CM2A8 fine powder were evenly mixed to obtain a mixed material; [0333] (2) the mixed material was pressed and molded at normal temperature, and put into a mold of a high temperature device for hot-pressed sintering. When the temperature was raised to a maximum temperature of 1670? C., and the hot-pressed sintering strength of 0.5 MPa was applied at this temperature, the refractory material with medium bulk density was prepared.

[0334] According to the same method as in Example 1, the phase analysis was carried out. The phase of the refractory material with medium bulk density comprised CA6 and CM2A8. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 31.5% and the phase content of CM2A8 was 67.1%.

[0335] The chemical composition analysis was carried out according to the same method as in Example 1, and based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 87.60% of Al.sub.2O.sub.3, 5.62% of MgO and 6.43% of CaO.

[0336] The phase analysis of the matrix part was carried out according to the same method as in Example 1, and the phase of the matrix part of the refractory material comprised CA6 and CM2A8. Based on the mass percentage of the phase of the matrix part in the refractory material, the phase content of CA6 was 78.2% and the phase content of C2M2A14 was 19.2%.

[0337] The chemical composition analysis of the matrix part was carried out according to the same method as in Example 1, and based on the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised 90.3% of Al.sub.2O.sub.3, 1.68% of MgO and 7.82% of CaO.

[0338] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.63 g/cm.sup.3.

[0339] The analysis was carried out according to the same method as in Example 1, the thermal conductivity of the obtained refractory material was 1.29 w/m.Math.k at 350? C.

[0340] According to the same method as in Example 1, the erosion thickness of the refractory material was 4.06 mm.

Example 15

[0341] (1) 947.4 g of CA6 fine powder, 15 g of fused magnesite fine powder and 38 g of active ?-Al.sub.2O.sub.3 fine powder were evenly mixed to obtain a mixed material; [0342] (2) the mixed was pressed and molded at normal temperature and light-calcined at 1350? C., and then put into a mold of a high temperature device for hot-pressed sintering. When the temperature was raised to 1500? C., the pressure was applied. When the temperature was raised to a maximum temperature of 1580? C., and the maximum strength of the hot-pressed sintering was 5 MPa, the refractory material with medium bulk density was prepared.

[0343] According to the same method as in Example 1, the phase analysis was carried out. The phase of the refractory material with medium bulk density comprised CA6 and C2M2A14. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 67.4% and the phase content of C2M2A14 was 30%.

[0344] The chemical composition analysis was carried out according to the same method as in Example 1. Based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 89.32% of Al.sub.2O.sub.3, 1.38% of MgO and 7.81% of CaO.

[0345] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.48 g/cm.sup.3.

[0346] The analysis was carried out according to the same method as in Example 1, and the thermal conductivity of the obtained refractory material was 1.00 w/m.Math.k at 350? C.

[0347] According to the same method as in Example 1, the erosion thickness of the refractory material was 5.60 mm.

Example 16

[0348] (1) 600 g of CM2A8 granular material (the maximum particle size is 8 mm), 80 g of CA6 fine powder, 281 g of aluminum hydroxide fine powder, 17.5 g of quick lime fine powder and 120 g of CM2A8 fine powder were evenly mixed to obtain a mixed material; [0349] (2) the mixed was pressed and molded at normal temperature and light-calcined at 1400? C., and then put into a mold of a high temperature device for hot-pressed sintering. When the temperature was raised to 1500? C., the pressure was applied gradually. The pressure was gradually increased while the temperature was increased. When the temperature was raised to a maximum temperature of 1750? C., and the maximum strength of the hot-pressed sintering was 0.5 MPa, the refractory material with medium bulk density was prepared.

[0350] According to the same method as in Example 1, the phase analysis was carried out. The phase of the refractory material with medium bulk density comprised CA6 and CM2A8. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 26.7% and the phase content of CM2A8 was 72%.

[0351] The chemical composition analysis was carried out according to the same method as in Example 1, and based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 86.65% of Al.sub.2O.sub.3, 6.05% of MgO and 6.22% of CaO.

[0352] The phase analysis of the matrix part was carried out according to the same method as in Example 1, and the phase of the matrix part of the refractory material comprised CA6 and CM2A8. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 68% and the phase content of CM2A8 was 30%.

[0353] The chemical composition analysis of the matrix part was carried out according to the same method as in Example 1, and based on the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised 89.03% of Al.sub.2O.sub.3, 2.52% of MgO and 7.60% of CaO.

[0354] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.90 g/cm.sup.3.

[0355] The analysis was carried out according to the same method as in Example 1, and the thermal conductivity of the obtained refractory material was 1.71 w/m.Math.k at 350? C.

[0356] According to the same method as in Example 1, the erosion thickness of the refractory material was 2.94 mm.

Example 17

[0357] (1) 100 g of C2M2A14 granular material (the maximum particle size is 1 mm), 630 g of CA6 fine powder, 18.7 g of quick lime fine powder, 13.4 g of high purity magnesia, 180 g of white-corundum fine powder and 58 g of active ?-Al.sub.2O.sub.3 fine powder were evenly mixed to obtain a mixed material; [0358] (2) the mixed was pressed and molded at normal temperature and light-calcined at 1450? C., and then put into a mold of a high temperature device for hot-pressed sintering. When the temperature was raised to 1500? C., the pressure was applied gradually. When the temperature was raised to a maximum temperature of 1620? C., and the maximum strength of the hot-pressed sintering was 8 MPa, the refractory material with medium bulk density was prepared.

[0359] According to the same method as in Example 1, the phase analysis was carried out. The phase of the refractory material with medium bulk density comprised CA6, C2M2A14 and MgO.Math.Al.sub.2O.sub.3. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 84.2%, the phase content of C2M2A14 was 9.28% and the phase content of MgO.Math.Al.sub.2O.sub.3 was 4.60%.

[0360] The chemical composition analysis was carried out according to the same method as in Example 1, and based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 89.14% Al.sub.2O.sub.3, 1.71% MgO and 7.65% CaO.

[0361] The phase analysis of the matrix part was carried out according to the same method as in Example 1, and the phase of the matrix part of the refractory material comprised CA6 and MgO.Math.Al.sub.2O.sub.3. Based on the mass percentage of the phase of the matrix part in the refractory material, the phase content of CA6 was 93.5% and the phase content of MgO.Math.Al.sub.2O.sub.3 was 5.22%.

[0362] The chemical composition analysis of the matrix part was carried out according to the same method as in Example 1, and based on the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised 90.07% Al.sub.2O.sub.3, 1.32% MgO and 7.67% CaO.

[0363] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.57 g/cm.sup.3.

[0364] The analysis was carried out according to the same method as in Example 1, and the thermal conductivity of the obtained refractory material was 1.15 w/m.Math.k at 350? C.

[0365] According to the same method as in Example 1, the erosion thickness of the refractory material was 5.04 mm.

Example 18

[0366] (1) 700 g of CA6 fine powder, 150 g of tabular corundum fine powder and 155 g of ?-Al.sub.2O.sub.3 fine powder were evenly mixed to obtain a mixed material; [0367] (2) the mixed material is pre-mold with water, dried and put into a mold of a high temperature device for heating. When the temperature was raised to 1550? C., and the hot-pressed sintering strength of 10 MPa was applied at this temperature, the refractory material with medium bulk density was prepared.

[0368] According to the same method as in Example 1, the phase analysis was carried out. The phase of the refractory material with medium bulk density comprised CA6 and corundum. Based on the mass percentage of the phase of refractory material, the phase content of CA6 was 66.4% and the phase content of corundum was 30%.

[0369] The chemical composition analysis was carried out according to the same method as in Example 1, and based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 94.10% of Al.sub.2O.sub.3 and 5.80% of CaO.

[0370] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.52 g/cm.sup.3.

[0371] The analysis was carried out according to the same method as in Example 1, and the thermal conductivity of the obtained refractory material was 1.02 w/m.Math.k at 350? C.

[0372] According to the same method as in Example 1, the erosion thickness of the refractory material was 4.55 mm.

Example 19

[0373] (1) 600 g of C2M2A14 granular material (the maximum particle size is 10 mm), 280 g of CA6 fine powder and 120 g of C2M2A14 fine powder were evenly mixed to obtain a mixed material; [0374] (2) the mixed is put into a mold of a high temperature device for hot-pressed sintering. The pressure was gradually applied from the temperature rising at room temperature. When the temperature was raised to a maximum temperature of 1610? C., and the maximum strength of hot press sintering was 6 MPa, the refractory material with medium bulk density was prepared.

[0375] According to the same method as in Example 1, the phase analysis was carried out. The phase of the refractory material with medium bulk density comprised CA6 and C2M2A14. Based on the mass percentage of the phase of the refractory, the phase content of CA6 was 26.7% and the phase content of C2M2A14 was 72%.

[0376] The chemical composition analysis was carried out according to the same method as in Example 1, and based on the mass percentage of the refractory, the chemical composition of the refractory material with medium bulk density comprised 88.87% of Al.sub.2O.sub.3, 3.36% of MgO and 7.16% of CaO.

[0377] The phase analysis of the matrix part was carried out according to the same method as in Example 1, and the phase of the matrix part of the refractory material comprised CA6 and C2M2A14. Based on the mass percentage of the phase of the matrix part in the refractory material, the phase content of CA6 was 68.1% and the phase content of C2M2A14 was 30%.

[0378] The chemical composition analysis of the matrix part was carried out according to the same method as in Example 1, and based on the mass percentage of the phase if the matrix part in the refractory material, the chemical composition of the matrix part of the refractory material comprised 90.46% of Al.sub.2O.sub.3, 1.31% of MgO and 7.82% of CaO.

[0379] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.60 g/cm.sup.3.

[0380] The analysis was carried out according to the same method as in Example 1, and the thermal conductivity of the obtained refractory material was 1.21 w/m.Math.k at 350? C.

[0381] According to the same method as in Example 1, the erosion thickness of the refractory material was 4.9 mm.

Example 20

[0382] (1) 400 g of CA6 granular material (the maximum particle size is 3 mm), 280 g of CA6 fine powder, 184 g of ?-Al.sub.2O.sub.3 powder, 120 g of tabular corundum powder and 22.2 g Ca(OH).sub.2 fine powder were evenly mixed to obtain a mixed material; [0383] (2) the mixed was pressed and molded at normal temperature and light-calcined at 1500? C., and then put into a mold of a high temperature device for hot-press sintering. When the temperature was raised to 1550? C., the pressure was applied gradually. When the temperature was raised to a maximum temperature of 1750? C., and the maximum strength of the hot-pressed sintering was 6 MPa, the refractory material with medium bulk density was prepared.

[0384] According to the same method as in Example 1, the phase analysis was carried out. The phase of the refractory material with medium bulk density comprised CA6 and corundum. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 85.5% and the phase content of corundum was 11.8%.

[0385] The chemical composition analysis was carried out according to the same method as in Example 1, and based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 92.03% of Al.sub.2O.sub.3 and 7.81% of CaO.

[0386] The phase analysis of the matrix part was carried out according to the same method as in Example 1, and the phase of the matrix part of the refractory material comprised CA6 and corundum. Based on the mass percentage of the phase of the matrix in the refractory material, the phase content of CA6 was 77.2% and the phase content of corundum was 20%.

[0387] The chemical composition analysis of the matrix part was carried out according to the same method as in Example 1, and based on the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised 93.2% of Al.sub.2O.sub.3 and 6.61% of CaO.

[0388] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.90 g/cm.sup.3.

[0389] The analysis was carried out according to the same method as in Example 1, and the thermal conductivity of the obtained refractory material was 1.67 w/m.Math.k at 350? C.

[0390] According to the same method as in Example 1, the erosion thickness of the refractory was 2.73 mm.

Example 21

[0391] (1) 100 g of C2M2A14 granular material (the maximum particle size is 1 mm), 324 g of CA6 fine powder, 53 g of quick lime fine powder, 28.5 g of high purity magnesia powder, 400 g of white corundum fine powder and 108 g of active ?-Al.sub.2O.sub.3 fine powder were evenly mixed to obtain a mixed material; [0392] (2) the mixed material was pressed and molded at normal temperature and light-calcined at 1450? C., and then put into a mold of a high temperature device for hot-pressed sintering. When the temperature was raised to 1500? C., the pressure was applied gradually. When the temperature was raised to a maximum temperature of 1550? C., and the maximum strength of the hot-pressed sintering was 1 MPa, the refractory material with medium bulk density was prepared.

[0393] According to the same method as in Example 1, the phase analysis was carried out. The phase of the refractory material with medium bulk density comprised CA6, C2M2A14 and MgO.Math.Al.sub.2O.sub.3. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 70.7%, the phase content of

[0394] C2M2A14 was 9.28% and the phase content of MgO.Math.Al.sub.2O was 10.0%.

[0395] The chemical composition analysis was carried out according to the same word as in Example 1, and based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 88.5% of Al.sub.2O.sub.3, 3.02% of MgO and 7.21% of CaO.

[0396] The phase analysis of the matrix part was carried out according to the same method as in Example 1, and the phase of the matrix part of the refractory material comprised CA6 and MgO.Math.Al.sub.2O.sub.3. Based on the mass percentage of the phase of matrix part of the refractory material, the phase content of CA6 was 78.6% and the phase content of MgO.Math.Al.sub.2O.sub.3 was 11.2%.

[0397] The chemical composition analysis of the matrix part was carried out according to the same method as in Example 1, and based on the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised 89.3% of Al.sub.2O.sub.3, 2.95% of MgO and 7.20% of CaO.

[0398] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.85 g/cm.sup.3.

[0399] The analysis was carried out according to the same method as in Example 1, and the thermal conductivity of the obtained refractory material was 1.96 w/m.Math.k at 350? C.

[0400] According to the same method as in Example 1, the erosion thickness of the refractory material was 4.83 mm.

Example 22

[0401] (1) 600 g of C2M2A14 granular material (the maximum particle size is 3 mm), 220 g of CA6 fine powder, 165.8 g of industrial alumina powder, 6.9 g of high purity magnesia powder and 18 g of aluminum hydroxide powder were evenly mixed to obtain a mixed material; [0402] (2) the mixed material was pressed and molded at normal temperature and light-calcined at 1450? C., and then put into a mold of a high temperature device for hot-pressed sintering. The pressure is gradually applied from the temperature rising at room temperature. When the temperature was raised to a maximum temperature of 1730? C., and the maximum strength of the hot-press sintering was 1.5 MPa, the refractory material with medium bulk density was prepared.

[0403] According to the same method as in Example 1, the phase analysis was carried out. The phase of the refractory material with medium bulk density comprised CA6, C2M2A14 and CM2A8. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 31.5%, the phase content of C2M2A14 was 60% and the phase content of CM2A8 was 7.48%.

[0404] The chemical composition analysis was carried out according to the same method as in Example 1, and based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 88.08% Al.sub.2O.sub.3, 3.41% MgO and 7.15% CaO.

[0405] The phase analysis of the matrix part was carried out according to the same method as in Example 1, and the phase of the matrix part of the refractory material comprised CA6 and CM2A8. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 78.8% and the phase content of CM2A8 was 20%.

[0406] The chemical composition analysis of the matrix part was carried out according to the same method as in Example 1, and based on the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised 89.03% Al.sub.2O.sub.3, 1.68% MgO and 7.74% CaO.

[0407] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.55 g/cm.sup.3.

[0408] The analysis was carried out according to the same method as in Example 1, and the thermal conductivity of the obtained refractory material was 1.23 w/m.Math.k at 350? C.

[0409] According to the same method as in Example 1, the erosion thickness of the refractory material was 3.82 mm.

Example 23

[0410] (1) 600 g of C2MA8 granular material (the maximum particle size is 3 mm), 220 g of CA6 fine powder, 80 g of C2M2A14 fine powder, 94 g of active alumina micro powder and 8.75 g of CaO fine powder were evenly mixed to obtain a mixed material; [0411] (2) the mixed material was pressed and molded at normal temperature and then put into a mold of a high temperature device for hot-pressed sintering. When the temperature was raised to a maximum temperature of 1740? C., the pressure was applied at this temperature, and the strength of the hot-pressed sintering was 0.5 MPa, the refractory material with medium bulk density was prepared.

[0412] According to the same method as in Example 1, the phase analysis was carried out. The phase of the refractory material with medium bulk density comprised CA6, C2M2A14 and CM2A8. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 31.5%, the phase content of C2M2A14 was 8% and the phase content of CM2A8 was 60%.

[0413] The chemical composition analysis was carried out according to the same method as in Example 1, and based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 87.50% Al.sub.2O.sub.3, 5.43% MgO and 6.08% CaO.

[0414] The phase analysis of the matrix part was carried out according to the same method as in Example 1, and the phase of the matrix part of the refractory material comprised CA6 and C2M2A14. Based on the mass percentage of the phase of the matrix part in the refractory material, the phase content of CA6 was 78.8% and the phase content of C2M2A14 was 20%.

[0415] The chemical composition analysis of the matrix part was carried out according to the same method as in Example 1, and based on the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised 90.60% Al.sub.2O.sub.3, 0.98% MgO and 7.76% CaO.

[0416] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.55 g/cm.sup.3.

[0417] The analysis was carried out according to the same method as in Example 1, and the thermal conductivity of the obtained refractory material was 1.30 w/m.Math.k at 350? C.

[0418] According to the same method as in Example 1, the erosion thickness of the refractory material was 3.84 mm.

Example 24

[0419] (1) 400 g of CA6 granular material (the maximum particle size is 3 mm), 450 g of CA6 fine powder, 238.40 g of industrial alumina fine powder, 11.8 g of fused magnesia fine powder and 8.7 g of CaO powder were evenly mixed to obtain a mixed material; [0420] (2) the mixed material was pressed and molded at normal temperature and then put into a mold of a high temperature device for hot-pressed sintering. When the temperature was raised to a maximum temperature of 1740? C., the pressure was applied at this temperature, and the strength of the hot-pressed sintering was 8 MPa, the refractory material with medium bulk density was prepared.

[0421] According to the same method as in Example 1, the phase analysis was carried out. The phase of the refractory material with medium bulk density comprised CA6, corundum and MgO.Math.Al.sub.2O.sub.3. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 82.8%, the phase content of corundum was 9.72% and the phase content of MgO.Math.Al.sub.2O.sub.3 was 4.0%.

[0422] The chemical composition analysis was carried out according to the same method as in Example 1, and based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 89.31% Al.sub.2O.sub.3, 1.14% MgO and 6.92% CaO.

[0423] The phase analysis of the matrix part was carried out according to the same method as in Example 1, and the phase of the matrix part of the refractory material comprised CA6, corundum and MgAl.sub.2O.sub.4. Based on the mass percentage of the phase of the matrix part in the refractory material, the phase content of CA6 was 73.8%, the phase content of corundum was 16.3% and the phase content of MgAl.sub.2O.sub.4 was 6.7%.

[0424] The chemical composition analysis of the matrix part was carried out according to the same method as in Example 1, and based on the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised 90.28% Al.sub.2O.sub.3, 1.91% MgO and 6.25% CaO.

[0425] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.55 g/cm.sup.3.

[0426] The analysis was carried out according to the same method as in Example 1, and the thermal conductivity of the obtained refractory material was 1.34 w/m.Math.k at 350? C.

[0427] According to the same method as in Example 1, the erosion thickness of the refractory material was 3.86 mm.

Embodiment 25

[0428] (1) 400 g of CA6 granular material (the maximum particle size is 3 mm), 80 g of 12CaO.Math.7Al.sub.2O.sub.3 fine powder, 384 g of active ?-Al.sub.2O.sub.3 micro powder and 154 g of white corundum powder were evenly mixed to obtain a mixed material; [0429] (2) the mixed material was pressed and molded at normal temperature and light-calcined at 1480? C., and then put into a mold of a high temperature device for hot-pressed sintering. When the temperature was raised to 1600? C., the pressure was applied gradually. When the temperature was raised to a maximum temperature of 1670? C., and the maximum strength of the hot-pressed sintering was 5.5 MPa, the refractory material with medium bulk density was prepared.

[0430] According to the same method as in Example 1, the phase analysis was carried out. The phase of the refractory material with medium bulk density comprised CA6 and corundum. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 82.7% and the phase content of corundum was 15%.

[0431] The chemical composition analysis was carried out according to the same method as in Example 1. Based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 92.80% Al.sub.2O.sub.3 and 6.52% CaO.

[0432] The phase analysis of the matrix part was carried out according to the same method as in Example 1, and the phase of the matrix part of the refractory material comprised CA6 and corundum. Based on the mass percentage of the phase of the matrix part in the refractory material, the phase content of CA6 was 72.5% and the phase content of corundum was 25%.

[0433] The chemical composition analysis of the matrix part was carried out according to the same method as in Example 1. Based on the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised 93.65% Al.sub.2O.sub.3 and 6.25% CaO.

[0434] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.55 g/cm.sup.3.

[0435] The analysis was carried out according to the same method as in Example 1, and the thermal conductivity of the obtained refractory material was 1.37 w/m.Math.k at 350? C.

[0436] According to the same method as in Example 1, the erosion thickness of the refractory material was 3.74 mm.

Example 26

[0437] (1) 600 g of C2MA8 granular material (the maximum particle size is 3 mm), 220 g of CA6 fine powder, 144.5 g of tabular corundum fine powder, 52.5 g of ?-Al.sub.2O.sub.3 fine powder and 8.7 g of CaO fine powder were evenly mixed to obtain a mixed material; [0438] (2) the mixed material was pressed and molded at normal temperature and then put into a mold of a high temperature device for hot-pressed sintering. When the temperature was raised to a maximum temperature of 1680? C., the pressure was applied at this temperature, and the strength of the hot-pressed sintering was 4.8 MPa, the refractory material with medium bulk density was prepared.

[0439] According to the same method as in Example 1, the phase analysis was carried out. The phase of the refractory material with medium bulk density comprised CA6, corundum and CM2A8. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 29.0%, the phase content of corundum was 9.15% and the phase content of CM2A8 was 57.5%.

[0440] The chemical composition analysis was carried out according to the same method as in Example 1, and based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 88.91% Al.sub.2O.sub.3, 4.92% MgO and 5.80% CaO.

[0441] The phase analysis of the matrix part was carried out according to the same method as in Example 1, and the phase of the matrix part of the refractory material comprised CA6 and corundum. Based on the mass percentage of the phase of the matrix part in the refractory material, the phase content of CA6 was 73.1% and the phase content of corundum was 25.0%.

[0442] The chemical composition analysis of the matrix part was carried out according to the same method as in Example 1, and based on the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised 93.65% Al.sub.2O.sub.3 and 6.25% CaO.

[0443] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.55 g/cm.sup.3.

[0444] The analysis was carried out according to the same method as in Example 1, and the thermal conductivity of the obtained refractory material was 1.53 w/m.Math.k at 350? C.

[0445] According to the same method as in Example 1, the erosion thickness of the refractory material was 3.98 mm.

Example 27

[0446] (1) 100 g of CA6 granular material (the maximum particle size is 1 mm), 630 g of CA6 fine powder, 92 g of sintered corundum powder, 162 g of ?-Al.sub.2O.sub.3 fine powder and 42 g of limestone fine powder were evenly mixed to obtain a mixed material; [0447] (2) the mixed was pressed and molded at normal temperature and then put into a mold of a high temperature device for hot-pressed sintering. When the temperature was raised to 1450? C., the pressure was applied gradually. When the temperature was raised to a maximum temperature of 1580? C., and the maximum strength of the hot-pressed strength was 7 MPa, the refractory material with medium bulk density was prepared.

[0448] According to the same method as in Example 1, the phase analysis was carried out. The phase of the refractory material with medium bulk density comprised CA6. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 100%.

[0449] The chemical composition analysis was carried out according to the same method as in Example 1, and based on the mass percentage of the matrix part of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 91.2% Al.sub.2O.sub.3 and 8.40% CaO.

[0450] The phase analysis of the matrix part was carried out according to the same method as in Example 1, and the phase of the matrix part of the refractory material comprised CA6. Based on the mass percentage of the phase of the matrix part of the refractory material, the phase content of CA6 was 100%.

[0451] The chemical composition analysis of the matrix part was carried out according to the same method as in Example 1, and based on the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised 91.1% Al.sub.2O.sub.3 and 8.40% CaO.

[0452] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.55 g/cm.sup.3.

[0453] The analysis was carried out according to the same method as in Example 1, and the thermal conductivity of the obtained refractory material was 0.56 w/m.Math.k at 350? C.

[0454] According to the same method as in Example 1, the erosion thickness of the refractory material was 4.66 mm.

Example 28

[0455] (1) 940 g of active alumina fine powder, 24.4 g light-calcined magnesium oxide powder and 80.9 g of Ca(OH).sub.2 were evenly mixed to obtain a mixed material; [0456] (2) the mixed material was pressed and molded at normal temperature and light-calcined at 1350? C., and then put into a mold of a high temperature device for hot-pressed sintering. When the temperature was raised to a maximum temperature of 1560? C., the hot-pressed sintering strength of 9 MPa was applied under this temperature, the refractory material with the medium volume density was prepared.

[0457] The phase analysis was carried out according to the same method as in Example 1, and the phase of said refractory material with medium volume density comprised CA6, corundum, and MgAl.sub.2O.sub.4. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 61.7%, the phase content of corundum was 20.3%, and the phase content of MgAl.sub.2O.sub.4 was 8%.

[0458] The chemical composition analysis was carried out according to the same method as in Example 1, and based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 90.4% Al.sub.2O.sub.3, 2.25% MgO and 5.80% CaO.

[0459] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.55 g/cm.

[0460] The analysis was carried out according to the same method as in Example 1, and the thermal conductivity of the obtained refractory material was 0.95w/m.Math.k at 350 C.

[0461] According to the same method as in Example 1, the erosion thickness of the refractory was 4.72 mm.

Example 29

[0462] (1) 500 g of CA6 granular material (the maximum particle size is 5 mm) and 500 g of CA6 fine were evenly mixed to obtain a mixed material; [0463] (2) the mixed material was put in a mold of a high temperature device for hot-pressed sintering. When the temperature was raised to a maximum temperature of 1620? C., the pressure was applied, and the maximum strength of the hot-pressed sintering was 3 MPa, the refractory material with medium bulk density was prepared.

[0464] According to the same method as in Example 1, the phase analysis was carried out. The phase of the refractory material with medium bulk density comprised CA6. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 99.5%.

[0465] The chemical composition analysis was carried out according to the same method as in Example 1, and based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 91.51% Al.sub.2O.sub.3 and 8.40% CaO.

[0466] The phase analysis of the matrix part was carried out according to the same method as in Example 1, and the phase of the matrix part of the refractory material comprised CA6. Based on the mass percentage of the phase of the matrix part in the refractory material, the phase content of CA6 was 100%.

[0467] The chemical composition analysis of the matrix part was carried out according to the same method as in Example 1, and based on the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised 91.52% Al.sub.2O.sub.3 and 8.40% CaO.

[0468] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.40 g/cm.sup.3.

[0469] The analysis was carried out according to the same method as in Example 1, and the thermal conductivity of the obtained refractory material was 0.46 w/m.Math.k at 350? C.

[0470] According to the same method as in Example 1, the erosion thickness of the refractory material was 3.95 mm.

Example 30

[0471] (1) 500 g of CA6 granular material (the maximum particle size is 5 mm) and 500 g of CA6 fine powder were evenly mixed to obtain a mixed material; [0472] (2) the mixed material was put into a mold of a high temperature device for hot-pressed sintering. When the temperature was raised to 1500? C., the pressure was applied. The pressure was increased gradually while the temperature was increased. When the temperature was raised to a maximum temperature of 1700? C., and the maximum strength of the hot-press sintering was 4 MPa, the refractory material with medium bulk density was prepared.

[0473] According to the same method as in Example 1, the phase analysis was carried out. The phase of the refractory material with medium bulk density comprised CA6. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 100%.

[0474] The chemical composition analysis was carried out according to the same method as in Example 1, and based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 91.51% Al.sub.2O.sub.3 and 8.39% CaO.

[0475] The phase analysis of the matrix part was carried out according to the same method as in Example 1, and the phase of the matrix part of the refractory material comprised CA6. Based on the mass percentage of the phase of the matrix part in the refractory material, the phase content of CA6 was 100%.

[0476] The chemical composition analysis of the matrix part was carried out according to the same method as in Example 1, and based on the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised 91.54% Al.sub.2O.sub.3 and 8.39% CaO.

[0477] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.82 g/cm.sup.3.

[0478] The analysis was carried out according to the same method as in Example 1, and the thermal conductivity of the obtained refractory material was 1.75 w/m.Math.k at 350? C.

[0479] According to the same method as in Example 1, the erosion thickness of the refractory material was 2.41 mm.

Example 31

[0480] (1) 500 g of CA6 granular material (the maximum particle size is 5 mm) and 500 g of CA6 fine were evenly mixed to obtain a mixed material; [0481] (2) the mixed material was put into a mold of a high temperature device for r hot-pressed sintering. When the temperature was raised to 1500? C., the pressure was applied gradually. The pressure was increased gradually while the temperature was increased. When the temperature was raised to a maximum temperature of 1750? C., and the maximum strength of the hot-pressed sintering was 2.5 MPa, the refractory material with medium bulk density was prepared.

[0482] According to the same method as in Example 1, the phase analysis was carried out. The phase of the refractory material with medium bulk density comprised CA6. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 99.5%.

[0483] The chemical composition analysis was carried out according to the same method as in Example 1, and based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 91.51% Al.sub.2O.sub.3 and 8.39% CaO.

[0484] The phase analysis of the matrix part was carried out according to the same method as in Example 1, and the phase of the matrix part of the refractory material comprised CA6. Based on the mass percentage of the phase of the matrix part in the refractory material, the phase content of CA6 was 99.5%.

[0485] The chemical composition analysis of the matrix part was carried out according to the same method as in Example 1, and based on the mass percentage of the matrix part of the refractory material, the chemical composition of the matrix part of the refractory material comprised 91.51% Al.sub.2O.sub.3 and 8.40% CaO.

[0486] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.90 g/cm.sup.3.

[0487] The analysis was carried out according to the same method as in Example 1, and the thermal conductivity of the obtained refractory material was 1.87 w/m.Math.k at 350? C.

[0488] According to the same method as in Example 1, the erosion thickness of the refractory material was 1.85 mm.

Example 32

[0489] (1) 430 g of CA6 fine powder, 29 g of fused magnesia powder, 41.3 g of limestone powder and 518.5 g of white corundum fine powder were evenly mixed to obtain a mixed material; [0490] (2) the mixed material was pressed and molded at normal temperature and light- -calcined at 1450? C., and then put into a mold of a high temperature device for hot-pressed sintering. When the temperature was raised to 1500? C., the pressure was applied gradually. When the temperature was raised to a maximum temperature of 1550? C., and the maximum strength of the hot-pressed sintering was 1 MPa, the refractory material with medium bulk density was prepared.

[0491] The phase analysis was carried out according to the same method as in Example 1, and the phase of said refractory with medium volume density comprised CA6 and MgO.Math.Al.sub.2O.sub.3. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 86.7% and the phase content of MgO.Math.Al.sub.2O.sub.3 was 10.0%.

[0492] The chemical composition analysis was carried out according to the same method as in Example 1, and based on the mass percentage of the refractory material, the chemical composition of the refractory material with medium bulk density comprised 95.72% Al.sub.2O.sub.3, 2.81% MgO and 7.36% CaO.

[0493] The bulk density analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 2.85 g/cm.

[0494] The analysis was carried out according to the same method as in Example 1, and the thermal conductivity of the obtained refractory material was 1.57 w/m.Math.k at 350? C.

[0495] According to the same method as in Example 1, the erosion thickness of the refractory material was 4.78 mm.

Comparative Example 1

[0496] The difference between Comparative Example 1 and Example 1 was that the conventional preparation method was used for Comparative Example 1, namely, the method of Example 1 in Chinese patent application CN107500747A was used to obtain refractory materials.

[0497] The analysis was carried out according to the same method as in Example 1, and the chemical composition of the refractory material comprised Al.sub.2O.sub.3 and CaO. Based on the mass percentage of the refractory material, Al.sub.2O.sub.3 was 92.03% and CaO was 7.12%.

[0498] The analysis was carried out according to the same method as in Example 1, and the phase of the refractory material comprised CA6, corundum, CA2 and CA. Based on the mass percentage of the phase of the refractory material, the phase content of CA6 was 68.75%, the phase content of corundum was 24.16%, the phase content of CA2 was 2.32% and the phase content of CA was 2.51%.

[0499] The analysis was carried out according to the same method as in Example 1, and the bulk density of the refractory material with medium bulk density was 3.02 g/cm.sup.3.

[0500] The analysis was carried out according to the same method as in Example 1, and the thermal conductivity of the obtained refractory material was 2.27 w/m.Math.k at 350? C.

[0501] According to the same method as in Example 1, the erosion thickness of the refractory material was 11 mm.

TABLE-US-00002 TABLE 2 list of the raw materials used in the Examples and Comparative Example, and the refractory material composition Mass ratio of Phase Chemical Phase Chemical granular composition composition composition composition materialto and and bulk and and fine content content density content of content powder (%) (%) (g/cm.sup.3) matrix (%) (%) Example 1 50:50 CA6:99.5 Al.sub.2O.sub.3:91.04 2.54 CA6:99.2 Al.sub.2O.sub.3:91.2 CaO:8.40 CaO:8.40 Example 2 40:60 CA6:86.50 Al.sub.2O.sub.3:92.60 2.55 CA6:78.8 Al.sub.2O.sub.3:93.28 Corundum:12 CaO:6.72 Corundum:20 CaO:6.60 Example 3 50:50 CA6:89.12 Al.sub.2O.sub.3:91.03 2.55 CA6:78.2 Al.sub.2O.sub.3:90.8 C2M2A14:9.4 MgO:0.43 C2M2A14:18.8 MgO:0.8 CaO:8.02 CaO:8.0 Example 4 50:50 CA6:89.04 Al.sub.2O.sub.3:90.34 2.53 CA6:78.2 Al.sub.2O.sub.3:90.3 CM2A8:9.4 MgO:0.78 CM2A8:18.8 MgO:1.68 CaO:7.86 CaO:7.81 Example 5 40:60 CA6:71.30 Al.sub.2O.sub.3:88.67 2.55 CA6:87.2 Al.sub.2O.sub.3:89.03 C2M2A14:23.5 MgO:1.03 C2M2A14:8.3 MgO:0.35 CaO:7.64 CaO:7.95 Example 6 60:40 CA6:31.5 Al.sub.2O.sub.3:87.92 2.55 CA6:78.8 Al.sub.2O.sub.3:93.28 CM2A8:58.4 MgO:4.82 Corundum:20 CaO:6.60 Corundum:7.78 CaO:6.10 Example 7 Full CA6:82.0 Al.sub.2O.sub.3:91.60 2.52 CA6:82.0 Al.sub.2O.sub.3:91.6 fine Corundum:16.5 CaO:6.92 Corundum:16.5 CaO:6.92 powder Example 8 Full CA6:78.6 Al.sub.2O.sub.3:92.4 2.52 CA6:78.6 Al.sub.2O.sub.3:92.4 fine Corundum:20.0 CaO:6.52 Corundum:20.0 CaO:6.52 powder Example 9 60:40 CA6:29.0 Al.sub.2O.sub.3:87.7 2.55 CA6:72.5 Al.sub.2O.sub.3:89.03 C2M2A14:60 MgO:3.74 CM2A8:25.0 MgO:2.10 CM2A8:8.41 CaO:6.68 CaO:7.02 Example 10 60:40 CM2A8:60 Al.sub.2O.sub.3:86.65 2.55 CA6:72.5 Al.sub.2O.sub.3:89.06 C2M2A14:9.07 MgO:5.53 C2M2A14:25.0 MgO:1.20 CA6:29 CaO:6.22 CaO:7.64 Example 11 60:40 CA6:38.7 Al.sub.2O.sub.3:88.07 2.65 CA6:98.7 Al.sub.2O.sub.3:90.5 CM2A8:59.5 MgO:5.04 CaO:8.40 CaO:6.89 Example 12 60:40 C2M2A14:60 Al.sub.2O.sub.3:89.32 2.82 CA6:100 Al.sub.2O.sub.3:90.8 CA6:38.7 MgO:2.74 CaO:8.40 CaO:7.41 Example 13 0:100 CA6:67.4 Al.sub.2O.sub.3:94.10 2.55 CA6:67.4 Al.sub.2O.sub.3:94.10 Corundum:30 CaO:5.80 Corundum:30 CaO:5.80 Example 14 60:40 CM2A8:67.1 Al.sub.2O.sub.3:87.6 2.63 CA6:78.2 Al.sub.2O.sub.3:90.3 CA6:31.5 MgO:5.62 CM2A8:19.2 MgO:1.68 CaO:6.43 CaO:7.82 Example 15 Full CA6:67.4 Al.sub.2O.sub.3:89.32 2.48 CA6:67.4 Al.sub.2O.sub.3:89.32 fine C2M2A14:30 MgO:1.38 C2M2A14:30 MgO:1.38 powder CaO:7.81 CaO:7.81 Example 16 60:40 CA6:26.7 Al.sub.2O.sub.3:86.65 2.90 CA6:68 Al.sub.2O.sub.3:89.03 CM2A8:72 MgO:6.05 Corundum:30 MgO:2.52 CaO:6.22 CaO:7.6 Example 17 10:90 CA6:84.2 Al.sub.2O.sub.3:89.14 2.57 CA6:93.5 Al.sub.2O.sub.3:97.07 C2M2A14:9.28 MgO:1.71 MgOAl.sub.2O.sub.3:5.22 MgO:1.32 MgOAl.sub.2O.sub.3 CaO:7.65 CaO:7.67 4.60 Example 18 Full CA6:66.4 Al.sub.2O.sub.3:94.10 2.52 CA6:66.4 Al.sub.2O.sub.3:94.10 fine Corundum:30 CaO:5.80 Corundum:30 CaO:5.80 powder Example 19 60:40 CA6:26.7 Al.sub.2O.sub.3:88.87 2.60 CA6:68.1 Al.sub.2O.sub.3:90.46 C2M2A14:72 MgO:3.36 Corundum:30 MgO:1.31 CaO:7.16 CaO:7.82 Example 20 40:60 CA6:85.5 Al.sub.2O.sub.3:92.03 2.90 CA6:77.2 Al.sub.2O.sub.3:93.2 Corundum:11.8 CaO:7.18 Corundum:20 CaO:6.61 Example 21 10:90 CA6:70.7 Al.sub.2O.sub.3:88.5 2.85 CA6:78.6 Al.sub.2O.sub.3:89.3 C2M2A14:9.28 MgO:3.02 MgOAl.sub.2O.sub.3:11.2 MgO:2.95 MgOAl.sub.2O.sub.3:10.0 CaO:7.21 CaO:7.20 Example 22 60:40 CA6:31.5 Al.sub.2O.sub.3:88.08 2.55 CA6:78.8 Al.sub.2O.sub.3:89.03 C2M2A14:60 MgO:3.41 CM2A8:20 MgO:1.68 CM2A8:7.48 CaO:7.15 CaO:7.74 Example 23 60:40 CA6:31.5 Al.sub.2O.sub.3:87.50 2.55 CA6:78.8 Al.sub.2O.sub.3:90.60 C2M2A14:8 MgO:5.43 C2M2A14:20 MgO:0.98 CM2A8:60 CaO:6.08 CaO:7.76 Example 24 40:60 CA6:82.8 Al.sub.2O.sub.3:89.31 2.55 CA6:73.8 Al.sub.2O.sub.3:90.28 Corundum:9.72 MgO:1.14 Corundum:16.3 MgO:1.91 MgO.Math.Al.sub.2O.sub.3:4.0 CaO:6.92 MgOAl.sub.2O.sub.3:6.7 CaO:6.25 Example 25 40:60 CA6:82.7 Al.sub.2O.sub.3:92.80 2.55 CA6:72.5 Al.sub.2O.sub.3:93.65 Corumdum:15 CaO:6.52 Corumdum:25 CaO:6.25 Example 26 60:40 CA6:29 Al.sub.2O.sub.3:88.91 2.55 CA6:73.1 Al.sub.2O.sub.3:93.65 CM2A8:57.5 MgO:4.92 Corumdum:25.0 Corundum:9.15 CaO:5.80 CaO:6.25 Example 27 10:90 CA6:100 Al.sub.2O.sub.3:91.2 2.55 CA6:100 Al.sub.2O.sub.3:91.1 CaO:8.40 CaO:8.40 Example 28 Full CA6:61.7 Al.sub.2O.sub.3:90.04 2.55 CA6:61.7 Al.sub.2O.sub.3:90.04 fine Corundum:20.3 MgO:2.25 Corundum:20.3 MgO:2.25 powder MgO.Math.Al.sub.2O.sub.3:8 CaO:5.80 MgAl.sub.2O.sub.3:8 CaO:5.80 Example 29 50:50 CA6:99.5 Al.sub.2O.sub.3:91.51 2.40 CA6:100 Al.sub.2O.sub.3:91.52 CaO:8.40 CaO:8.40 Example 30 50:50 CA6:100 Al.sub.2O.sub.3:91.51 2.82 CA6:100 Al.sub.2O.sub.3:91.54 CaO:8.39 CaO:8.39 Example 31 50:50 CA6:99.5 Al.sub.2O.sub.3:91.51 2.90 CA6:99.5 Al.sub.2O.sub.3:91.51 CaO:8.39 CaO:8.40 Example 32 0:100 CA6:86.7 Al.sub.2O.sub.3:95.72 2.85 CA6:86.7 Al.sub.2O.sub.3:95.72 MgOAl.sub.2O.sub.3:10.0 MgO:2.81 MgOAl.sub.2O.sub.3:10.0 MgO:2.81 CaO:7.36 CaO:7.36 Comparative 65:35 CA6:68.75 Al.sub.2O.sub.3:92.03 3.02 CA6:42.35 Al.sub.2O.sub.3:91.65 Example 1 Corundum:24.16 CaO:7.12 Corundum:42.47 CaO:7.48 CA2:2.32 CA2:6.45 CA:2.51 CA:7.02

TABLE-US-00003 TABLE 3 the thermal conductivity at 350? C. and erosion thickness of the refractory material obtained by Examples and Comparative Examples Thermal conductivity at Erosion 350? C. (w/m .Math. K) thickness (mm) Example 1 0.61 3.12 Example 2 1.02 2.87 Example 3 0.95 3.66 Example 4 0.96 3.70 Example 5 0.84 3.46 Example 6 1.32 3.72 Example 7 0.9 4.48 Example 8 0.92 4.34 Example 9 1.42 4.21 Example 10 1.48 4.28 Example 11 1.12 3.67 Example 12 1.55 3.08 Example 13 1.02 4.55 Example 14 1.29 4.06 Example 15 1.00 5.60 Example 16 1.71 2.94 Example 17 1.15 5.04 Example 18 1.02 4.55 Example 19 1.21 4.90 Example 20 1.67 2.73 Example 21 1.96 4.83 Example 22 1.23 3.82 Example 23 1.30 3.84 Example 24 1.34 3.86 Example 25 1.37 3.74 Example 26 1.53 3.98 Example 27 0.56 4.66 Example 28 0.95 4.72 Example 29 0.46 3.95 Example 30 1.75 2.41 Example 31 1.87 1.85 Example 32 1.57 4.78 Comparative 2.27 11 Example 1

Experimental Example 1

[0502] The refractory material obtained in Example 1 was compared with the CA6 castable prepared in Comparative Example 1.

[0503] Wherein the treatment method was as follows: the CA6 refractory material obtained in Example 1 and the CA6 castable obtained in Comparative Example 1 were put into a high temperature furnace, heated to 1550? C. and treated for 3 h. The morphology after treatment is shown in FIG. 1.

[0504] As can be seen from FIG. 1, the sintering shrinkage of the two samples is very small and the surface is very clean.

[0505] FIG. 2 and FIG. 3 are schematic diagrams of the resistance to steel slag erosion of the samples obtained in Example 1 and Comparative Example 1 after 1550? C. for 3 h, respectively. Wherein the steps of the resistance to steel slag erosion after 1550? C. for 3 h are shown as follows: making a crucible with refractory material, putting steel slag into it, heating to 1550? C., keeping it for 3 h and cooling. The cooled sample is cut along the middle to measure the erosion thickness and corrosion of the slag.

[0506] As can be seen from FIG. 2 and FIG. 3, the steel slag in the CA6 castable sample of Comparative Example 1 has penetrated deeply, and the steel slag has penetrated through the crucible of the sample to the outside of the crucible, indicating that the castable has poor resistance and permeability to the erosion of slag. If the sample is used for permanent lining of ladle, steel leakage or red envelope of ladle will be caused if the working lining disappears. However, in Example 1, the permeability and erosion resistance to slag is very good, although its bulk density is only 2.55 g/cm.sup.3, indicating that Example 1 has good permeability resistance to slag.

[0507] The above is only a preferred embodiment of the present application and is not intended to limit the present application in other forms. Any person familiar with this field may make use of the disclosed technical content to change or adapt it to embodiments with equivalent variations. However, any simple modifications, equivalent variations, or adaptations of the above embodiments based on the technical essence of the present application, without departing from the content of the technical solution of the present application, still fall within the scope of protection of the technical solution of the present application.