METHOD FOR USING COLD ROLLING MAGNETIC FILTRATION WASTE

Abstract

Disclosed is a method for using cold rolling magnetic filtration waste, comprising using the cold rolling magnetic filtration waste as a fluxing agent for a high-ash-fusion coal so as to achieve the technical requirements of a high melting point coal in dry coal powder gasification and liquid slagging. The cold rolling magnetic filtration waste contains solid particulates with very fine particles (iron-containing particles mainly produced by friction), and the surface thereof has a cold rolling oil attached thereto, and same reacts with other aluminosilicates in coal ash at a high temperature to produce low temperature eutectic compounds such as fayalite (Fe.sub.2SiO.sub.4) and hercynite (Fe.sub.2Al.sub.2O.sub.4). The fluxing agent has characteristics such as having fine particles, being free of inorganic mineral substances, having an effective ingredient in a high content, operation thereof being simple, and being free of pollution.

Claims

1. A method for utilizing cold-rolling magnetic filtration waste, including the following step: using cold-rolling magnetic filtration waste for a flux, wherein the waste is mixed with a coal powder matrix to obtain the flux.

2. The method for utilizing cold-rolling magnetic filtration waste according to claim 1, wherein a weight ratio of the cold-rolling magnetic filtration waste to the coal powder matrix is from 1:1 to 1:5.

3. The method for utilizing cold-rolling magnetic filtration waste according to claim 1, wherein the cold-rolling magnetic filtration waste comprises a solid particulate matter and rolling oil adsorbed on a surface of the solid particulate matter, wherein the solid particulate matter has an average particle diameter of less than 5 m, wherein the solid particulate matter comprises iron-containing particles generated by friction.

4. The method for utilizing cold-rolling magnetic filtration waste according to claim 3, wherein a mass fraction of the rolling oil in the cold-rolling magnetic filtration waste is 40-80%.

5. The method for utilizing cold-rolling magnetic filtration waste according to claim 4, wherein the rolling oil consists of lubricating base oil and an additive.

6. The method for utilizing cold-rolling magnetic filtration waste according to claim 1, wherein the coal powder is high-ash-melting-point coal having an ash melting point of not less than 1450 C.

7. The method for utilizing cold-rolling magnetic filtration waste according to claim 1, wherein after the cold-rolling magnetic filtration waste is mixed with the coal powder, the mass of the solid particulate matter is from 0.5 to 5% based on the mass of coal ash in the coal powder.

8. The method for utilizing cold-rolling magnetic filtration waste according to claim 7, wherein the mass of the solid particulate matter is from 1 to 3% based on the mass of the coal ash in the coal powder.

9. The method for utilizing cold-rolling magnetic filtration waste according to claim 2, wherein the cold-rolling magnetic filtration waste comprises a solid particulate matter and rolling oil adsorbed on a surface of the solid particulate matter, wherein the solid particulate matter has an average particle diameter of less than 5 m, wherein the solid particulate matter comprises iron-containing particles generated by friction.

10. The method for utilizing cold-rolling magnetic filtration waste according to claim 9, wherein a mass fraction of the rolling oil in the cold-rolling magnetic filtration waste is 40-80%.

11. The method for utilizing cold-rolling magnetic filtration waste according to claim 10, wherein the rolling oil consists of lubricating base oil and an additive.

Description

DESCRIPTION OF THE DRAWINGS

[0024] By reading the detailed description of the non-limiting Examples with reference to the following drawings, other features, objects, and advantages of the present disclosure will become more apparent:

[0025] FIG. 1 shows the influence of the flux content on the characteristic melting temperatures of coal sample A.

[0026] FIG. 2 shows the influence of the flux content on the characteristic melting temperatures of coal sample B.

DETAILED DESCRIPTION

[0027] The present disclosure will be illustrated in detail with reference to the following specific Examples. The following Examples will help those skilled in the art to further understand the present disclosure, but do not limit the present disclosure in any way. It should be noted that, for those skilled in the art, variations and modifications can be made without departing from the concept of the present disclosure. They all fall in the protection scope of the present disclosure.

Example 1

[0028] Finely ground high-ash-melting-point raw coal (having a particle size of less than 0.2 mm) was mixed uniformly with cold-rolling magnetic filtration waste in a certain ratio. The solid content of the cold-rolling magnetic filtration waste was 0.5%-5% of the mass of the coal ash in the raw coal sample. The mixed sample was placed in a porcelain boat and then put in a muffle furnace. After incineration at 850 C. for a certain period of time, the sample was taken out for rapid cooling. Subsequently, it was put in a vacuum drying oven to dry at 105 C. for 36 h. Then, it was sealed for later use. As such, an ash sample was prepared. For the melting property of the coal ash, a smart ash melting point detector was used to measure the melting temperature of the ash in a weakly reducing atmosphere using an ash cone method according to GB/T219-1996.

[0029] The basic properties of the coal used in Example 1 are listed in Tables 1 to 4. As can be seen from Tables 3 and 4, because the SiO.sub.2 and Al.sub.2O.sub.3 contents in the ash components were all 35% or higher, the ash melting temperatures were high. The ash melt flow temperatures of the two selected coal samples were greater than 1500 C. According to MT/T853.2 Grading Criteria For Coal Ash Flowability, they were high flow temperature ash, and did not meet the requirements of liquid slag tapping furnaces for dry coal powder entrained-flow bed gasification processes (FT<1450 C., Shell gasification furnace coal FT<1380 C.).

TABLE-US-00001 TABLE 1 Industrial analysis of coal samples, % Coal Moisture, Ash, Volatiles, Fixed carbon, sample M.sub.ad A.sub.d V.sub.daf FC.sub.d A 1.82 10.60 7.19 81.5 B 1.40 22.04 11.82 68.10

TABLE-US-00002 TABLE 2 Elemental analysis of coal samples, % Coal sample Carbon Hydrogen Nitrogen Sulfur A 92.17 3.14 1.07 0.46 B 74.21 3.04 0.56 1.07

TABLE-US-00003 TABLE 3 Coal ash composition of coal samples, % Coal sample SiO.sub.2 Al.sub.2O.sub.3 CaO Fe.sub.2O.sub.3 MgO Na.sub.2O TiO.sub.2 SO.sub.3 A 41.0 41.2 4.29 4.28 0.61 0.93 2.65 2.41 B 45.2 36.0 5.59 4.96 0.85 0.34 1.98 2.90

TABLE-US-00004 TABLE 4 Coal ash melting temperature, C. Deformation Softening Flow Coal temperature, temperature, Temperature, sample DT ST FT A 1428 1495 1530 B 1412 1489 1510

[0030] In Example 1, the raw coal sample was used as the powder coal matrix, and the cold-rolling magnetic filtration waste was used as the flux. Four coal ash melting temperature tests were conducted after adding different proportions of the flux. The addition scheme is shown in Table 5. The addition condition was a ratio of the iron powder content in the cold-rolling magnetic filtration waste to the amount of the coal ash sample in the coal sample.

[0031] FIGS. 1 and 2 depict curves respectively showing the influence of the measured flux addition amount (the ratio of the iron powder content in the cold-rolling magnetic filtration waste to the coal ash sample amount in the coal sample) on the characteristic ash melting temperatures of coal sample A and coal sample B. As can be seen from FIGS. 1 and 2, when the cold-rolling magnetic filtration waste was added as a flux, and the friction-born iron powder contained therein was added in an amount that was increased to 2% of the total coal ash amount, the deformation temperature (DT), softening temperature (ST) and the flow temperature (FT) of the coal sample showed a similar trend of change, i.e. decreased obviously; particularly, decreased by about 200 C. However, when the addition amount was further increased, the characteristic temperatures of the coal sample substantially did not change. When the addition amount reached 2%, the ash flow temperature of raw coal sample A decreased from 1530 C. to 1344 C., and the ash flow temperature of raw coal sample B decreased from 1510 C. to 1340 C., both less than 1350 C., thereby both meeting the technical requirements of dry coal powder gasification and liquid slag tapping of Shell gasifiers.

[0032] In summary, the above Examples are only preferred embodiments of the present disclosure, and are not intended to limit the scope of the present disclosure in implementation. Any equivalent variations and modifications based on the shapes, structures, features and spirit described in the scope of the claims of the present disclosure should be included in the scope of the claims of the present disclosure.