METHOD FOR MANUFACTURING COMPOSITE CARBONATE BY USING COMBUSTION ASH

Abstract

The present invention provides a method for manufacturing a composite carbonate in a semi-dry manner by using combustion ash and, more specifically, provides a method for manufacturing a composite carbonate in a semi-dry manner by using combustion ash, the method comprising a step of adding a small amount of water to combustion ash containing calcium ions in an atmosphere of carbon dioxide. According to the present invention, carbon mineralization is carried out in a semi-dry manner by the manufacturing method, so that the composite carbonate can be efficiently produced. In addition, the composite carbonate can be utilized as a component for a concrete composition.

Claims

1. A semi-dry method for manufacturing a composite carbonate from combustion ash, the method comprising a step of adding water to calcium ion-containing combustion ash in a carbon dioxide atmosphere.

2. The semi-dry method of claim 1, wherein the water is added in an amount of 10 to 100 parts by weight, based on 100 parts by weight of the combustion ash.

3. The semi-dry method of claim 1, wherein the combustion ash is solid refuse fuel combustion ash or circulating fluidized bed combustion ash.

4. The semi-dry method of claim 1, wherein the combustion ash is fly ash or bottom ash.

5. The semi-dry method of claim 1, wherein the carbon dioxide atmosphere contains carbon dioxide at a concentration of 10% by volume to 100% by volume.

6. A method for preparation of a concrete composition, comprising a step of blending the composite carbonate manufactured by the method of claim 1 with water, cement, sand, pebbles, and an admixture.

7. A solidifying composition, comprising the composite carbonate manufactured by the method of claim 1.

8. A filler composition, comprising the composite carbonate manufactured by the method of claim 1.

9. The semi-dry method of claim 2, wherein the combustion ash is fly ash or bottom ash.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 shows appearances of combustion ashes used in the present disclosure.

[0022] FIG. 2 shows SEM images of combustion dusts.

[0023] FIG. 3 shows particle size distributions of combustion dusts.

[0024] FIG. 4 shows EDS analysis results of combustion ashes.

[0025] FIG. 5 shows particle size distributions of bottom ashes as measured by sieving.

[0026] FIG. 6 shows images of bottom ashes divided by sieving according to particle sizes.

[0027] FIG. 7 shows XRD analysis results of combustion ashes.

[0028] FIG. 8 shows TG-DTA analysis results of combustion ashes.

[0029] FIG. 9 schematically shows a carbon reactor used for carbon mineralization of combustion ash in the present disclosure.

[0030] FIG. 10 shows appearances of slaked lime according to amounts of water added.

[0031] FIG. 11 shows characteristics of minerals according to carbon mineralization conducted by adding water to slaked lime, as measured by Q-XRD.

[0032] FIG. 12 shows changes in characteristics of minerals according to carbon mineralization conducted by adding water to slaked lime, as measured by Q-XRD.

[0033] FIG. 13 shows characteristics of minerals according to carbon mineralization conducted by adding water to SRF combustion ash, as measured by Q-XRD, in which content % is given all of the ingredients in the samples.

[0034] FIG. 14 shows changes in characteristics of minerals according to carbon mineralization conducted by adding water to SRF combustion ash, as measured by Q-XRD, in which content % is given to calcium-containing ingredients in the samples.

[0035] FIG. 15 shows characteristics of minerals according to reaction time, as measured by Q-XRD, in which content % is given all of the ingredients in the samples.

[0036] FIG. 16 shows changes in characteristics of minerals according to reaction time, as measured by Q-XRD, in which content % is given to calcium-containing ingredients in the samples.

[0037] FIG. 17 shows characteristics of minerals according to carbon dioxide concentration, as measured by Q-XRD, in which content % is given all of the ingredients in the samples.

[0038] FIG. 18 shows changes in characteristics of minerals according to carbon dioxide concentration, as measured by Q-XRD, in which content % is given to calcium-containing ingredients in the samples.

DETAILED DESCRIPTION

[0039] In a power plant such as a heat power plant, combustion leaves combustion ash. When subjected to carbon mineralization, combustion ash can be advantageously utilized as an ingredient in a concrete composition. However, conventional carbon mineralization resorts mainly to a wet method using an excess of water or a dry method that is conducted at high temperatures. Due to the problems thereof, the wet and dry methods are difficult to utilize.

[0040] The present inventors conducted a study to offer a commercialized carbon mineralization strategy for combustion ash and found that a composite carbonate can be obtained using a semi-dry carbon mineralization method in which water is added in an amount of 10 to 100 parts by weight to combustion ash, based on 100 parts by weight of combustion ash, leading to the present disclosure.

[0041] Therefore, the present disclosure provides a method for manufacturing a composite carbonate from combustion ash, the method comprising a step of adding water in an amount of 10 to 100 parts by weight to 100 parts by weight of combustion ash.

[0042] As a rule, Ca compounds such as gehlenite (Ca.sub.2Al[AlSiO.sub.7]), anhydrite (CaSO.sub.4), lime (Ca(OH).sub.2), and the like, exist in solid refuse fuel combustion ash and circulating fluidized bed combustion ash. In the present disclosure, a composite carbonate is manufactured by preparing CaCO.sub.3 through a reaction between a small amount of water and CO.sub.2.

[0043] The reaction may be conducted according to the following Reaction Scheme 1:

CaO+H.sub.2O.fwdarw.Ca(OH).sub.2

Ca(OH).sub.2+CO.sub.2.fwdarw.CaCO.sub.3+H.sub.2O  <Reaction Scheme 1>

[0044] As illustrated above, the addition of water is indispensable for the production of CaCO.sub.3 by reacting a Ca compound with CO.sub.2. Generally, use of a large amount of water is followed by consuming much energy and time in drying the carbonate to be used in cement. The present disclosure provides a method for synthesizing a composite carbonate in a semi-dry manner designed to minimize the amount of water. Small energy can be consumed for drying the composite carbonate because it is synthesized with a small amount of water. The composition carbonate is easy to handle because it is in a powder form.

[0045] The combustion ash may be solid refuse fuel (SRF) combustion ash or circulating fluidized bed combustion (CFBC) combustion ash. For the SRF combustion ash and the CFBC combustion ash, both fly ash and bottom ash may be available.

[0046] In addition, the water may be added in an amount of 10 to 100 parts by weight, based on 100 parts by weight of the combustion ash. When the amount of water exceeds 100 parts by weight, much energy and time is required for the drying process. Water less than 10 parts by weight is insufficient to evenly wet the combustion ash and thus cannot allow the production of uniform composite carbonate. When account is taken of the energy and time for demoisturization, water is more preferably added in an amount of 25 to 75 parts by weight.

[0047] In the manufacturing method of the present disclosure, a small amount of water is added to combustion ash in a carbon dioxide atmosphere so that Ca compounds in the combustion ash reacts with carbon dioxide to produce calcium carbonate (CaCO.sub.3). This reaction is carried out in a carbon dioxide reactor. In some particular embodiments, the reactor contains carbon dioxide at a concentration of 10% by volume to 100% by volume.

[0048] The combustion ash may contain calcium oxide (CaO), silicon dioxide (SiO.sub.2), aluminum oxide (Al.sub.2O.sub.3), sodium oxide (Na.sub.2O), iron oxide (Fe.sub.2O.sub.3), magnesium oxide, potassium oxide (K.sub.2O), sulfur oxide (SO.sub.3), and phosphorus pentoxide (P.sub.2O.sub.5).

[0049] The SRF fly ash may contain 10 to 25% by weight of calcium oxide (CaO), 15 to 40% by weight of silicon dioxide (SiO.sub.2), 10 to 20% by weight of aluminum oxide (Al.sub.2O.sub.3), 10 to 20% by weight of sodium oxide (Na.sub.2O), 1 to 5% by weight of iron oxide (Fe.sub.2O.sub.3), 0.5 to 3% by weight of magnesium oxide, 1 to 5% by weight of potassium oxide (K.sub.2O), 0.5 to 2% by weight of sulfur oxide (SO.sub.3), and 1 to 5% by weight of phosphorus pentoxide (P.sub.2O.sub.5).

[0050] The CFBC fly ash may contain 5 to 15% by weight of calcium oxide (CaO), 70 to 90% by weight of silicon dioxide (SiO.sub.2), 2 to 4% by weight of aluminum oxide (Al.sub.2O.sub.3), 0.5 to 2% by weight of sodium oxide (Na.sub.2O), 0.5 to 1% by weight of iron oxide (Fe.sub.2O.sub.3), 0.1 to 1% by weight of magnesium oxide (MgO), 0.1 to 0.5% by weight of potassium oxide (K.sub.2O), 0.01 to 1% by weight of sulfur oxide (SO.sub.3), and 0.1 to 1.5% by weight of phosphorus pentoxide (P.sub.2O.sub.5).

[0051] The SRF bottom ash may contain 10 to 40% by weight of calcium oxide (CaO), 10 to 30% by weight of silicon dioxide (SiO.sub.2), 5 to 15% by weight of aluminum oxide (Al.sub.2O.sub.3), 1 to 3% by weight of sodium oxide (Na.sub.2O), 10 to 20% by weight of iron oxide (Fe.sub.2O.sub.3), 5 to 15% by weight of magnesium oxide (MgO), 0.1 to 1% by weight of potassium oxide (K.sub.2O), 0.01 to 0.5% by weight of sulfur oxide (SO.sub.3), and 5 to 15% by weight of phosphorus pentoxide (P.sub.2O.sub.5).

[0052] The CFBC bottom ash may contain 15 to 40% by weight of calcium oxide (CaO), 10 to 30% by weight of silicon dioxide (SiO.sub.2), 3 to 8% by weight of aluminum oxide (Al.sub.2O.sub.3), 1 to 3% by weight of sodium oxide (Na.sub.2O), 10 to 15% by weight of iron oxide (Fe.sub.2O.sub.3), 5 to 15% by weight of magnesium oxide (MgO), 0.1 to 1% by weight of potassium oxide (K.sub.2O), 15 to 35% by weight of sulfur oxide (SO.sub.3), and (P.sub.2O.sub.5) 0.01 to 0.2% by weight of phosphorus pentoxide.

[0053] In addition, the present disclosure provides a method for preparing a concrete composition, the method comprising a step of blending the composite carbonate manufactured by the manufacturing method with water, cement, sand, pebbles, and an admixture.

[0054] The composition may comprise 50 to 70 parts by weight of water, 15 to 20 parts by weight of the composite carbonate, 280 to 320 parts by weight of sand, 300 to 350 parts by weight of pebbles, 0.5 to 1.5 parts by weight of an admixture, based on 100 parts by weight of the cement.

[0055] The cement may be Portland cement, the admixture may be a polycarbonate admixture, and the cement composition may comprise any ingredient available for typical cement composition in addition to the composite carbonate, without limitations imparted thereto.

[0056] Furthermore, the present disclosure provides a solidifying agent composition or filler composition comprising the composite carbonate manufactured by the manufacturing method.

[0057] The solidifying agent composition comprising the composite carbonate may be prepared through a step of adding sand, water, cement, or an admixture to the composite carbonate, and may contain any ingredient available for a concrete solidifying agent, without limitations.

[0058] The filler composition comprising the composite carbonate may be prepared through a step of adding sand, water, cement, or an admixture to the composite carbonate, and may contain any ingredient available for a concrete filler, without limitations.

[0059] Hereinafter, the present disclosure will be described in detail through the following Examples. It should be obvious to a person skilled in the art that the Examples are given to illustrate, but are not to be construed to limit the present disclosure.

EXAMPLES

[0060] A better understanding of the present disclosure may be obtained through the following examples which are set forth to illustrate, but are not to be construed as limiting the present disclosure.

Example 1: Characterization of Combustion Ash

[0061] 1.1. Preparation of Combustion Ash

[0062] In this Example, solid refuse fuel (SRF) combustion ash and circulating fluidized bed combustion (CFBC) combustion ash were used for manufacturing composite carbonates. SRF fly ash (combustion dust) and bottom ash (combustion residue) were purchased from the Kwangju-Jeonnam Branch of the Korea District Heating Corporation while CFBC fly ash and bottom ash were obtained from the Samcheok Heat Power Plant in Korea Southern Power Co. Ltd.

[0063] Appearances of the combustion ashes are depicted in FIG. 1.

[0064] 1.2. Analysis for Chemical Ingredients of Combustion Ashes

[0065] The obtained combustion ashes were analyzed for chemical components, using ICP-OES (OPTIMA 8300, PERKINELMER), and the results are summarized in Table 1, below. For comparison, the SRF combustion dust obtained from Busan E&E (Busan Environment and Energy) and the coal combustion dust obtained from a coal power plant were analyzed for chemical components.

TABLE-US-00001 TABLE 1 Cl Sample SiO.sub.2 Al.sub.2O.sub.3 Fe.sub.2O.sub.3 CaO MgO Na.sub.2O K.sub.2O SO.sub.3 P.sub.2O.sub.5 LOI (ppm) SRF combustion dust 24.9 13.2 2.56 17.1 1.82 13.1 2.36 1.29 2.96 19.3 128,000 SRF combustion residue 85.0 2.90 0.87 7.27 0.50 1.01 0.35 0.18 0.94 0.02 2,000 CFBC combustion dust 19.7 9.06 16.6 25.3 11.2 1.91 0.89 0.15 11.1 3.73 28,800 CFBC combustion residue 20.9 5.19 12.9 23.1 7.94 1.27 0.61 24.7 0.13 2.56 8,600 Busan SRF combustion dust 7.56 6.57 2.00 15.4 1.66 24.7 2.94 0.55 2.42 33.9 51,924 (obtained March, 2015) Coal combustion dust 54.9 20.6 6.77 5.3 2.10 1.50 1.72 0.76 0.60 5.05 tr

[0066] SRF combustion dust contained CaO in an amount of 17.1%, Na.sub.2O in an amount of 13.1%, and CI at a content of 128,000 ppm, which were measured to be similar to the chemical composition of Busan E&E SRF combustion dust.

[0067] 1.3. SEM Analysis

[0068] Powder morphologies of combustion dusts were observed. Images of combustion dust taken by a scanning electron microscope (JSM-7610F, JEOL) are given in FIG. 2.

[0069] In addition, FIG. 3 shows the particle size distributions, with average particle diameters of 25.1 μm for SRF combustion dust, 15.5 μm for CFBC combustion dust, and 4.2 μm for Busan SRF combustion dust.

[0070] 1.4. EDS Analysis

[0071] For component analysis, combustion dusts and combustion residues were subjected to energy dispersive X-ray spectroscopy (X-MAX 50, OXFORD), and the results are given in FIG. 4.

[0072] As can be seen in FIG. 4, Ca was observed to be distributed.

[0073] 1.5. Particle Size Distribution by Sieving

[0074] The combustion ashes were sieved and measured for particle size distribution in order to determine whether the combustion ashes meet dimensions of fine aggregates for concrete.

[0075] As shown in FIGS. 5 and 6, SRF combustion ash and CFBC bottom ash were finer than woodchip combustion residues and coal combustion residues.

[0076] From the results, it can be understood that particle sizes of SRF combustion ash and CFBC bottom ash are fine and do not meet the dimension of fine aggregates for concrete (KS F 2526).

[0077] 1.6. XRD Analysis

[0078] Components of the combustion ashes and combustion residues were analyzed using XRD (G-MAX 2500, RIGAKU), and the results are given in FIG. 7.

[0079] As is understood from data of FIG. 7, Ca compounds were detected in SRF combustion ash, but not in SRF bottom ash.

[0080] 1.7. TG-DTA Analysis

[0081] The combustion dusts and combustion residues were quantitatively analyzed for Ca compounds by thermogravimetry (TG-DTA, Thermo Plus Evo 2, RIGAKU), and the results are given in FIG. 8.

[0082] As shown in FIG. 8, Ca compounds were most abundantly detected in SRF combustion ash, amounting to about 24%.

[0083] 1.8. Waste Leaching Test

[0084] In order to determine whether combustion ashes and combustion residues are designated waste or general waste, a waste leaching test was performed on SRF and CFBC combustion dusts and combustion residues, and Busan SRF combustion ashes according to the Standard Test for Wastes (the National Institute of Environmental Research Notice No. 2017-20, Aug. 11, 2017).

[0085] The analysis results are summarized in Table 2.

TABLE-US-00002 TABLE 2 Busan SRF Standard Combustion for SRF CFBC ash Analysis designated Combustion dust Combustion residue Combustion dust Combustion residue (combustion Item waste KICET*.sup.1 KCL*.sup.2 KICET KCL KICET KCL KICET KCL dust) Pb or its Cpd. 3 mg/l or more not 0.11  not not not 0.05 not not 32.7  detected detected detected detected detected detected Cu or its Cpd. 3 mg/l or more not 0.127 not 0.028 not 0.03 not 0.013 0.24 detected detected detected detected As or its Cpd. 1.5 mg/l or more not not not not not not not not 0.01 detected detected detected detected detected detected detected detected Pb or its Cpd. 0.005 mg/l or more not not not not not not not not 0.13 detected detected detected detected detected detected detected detected Cd or its Cpd. 3 mg/l or more not not not not not not not not 0.01 detected detected detected detected detected detected detected detected Hexavalent Cr 1.5 mg/l or more 0.01 not 0.05 not not not not not not Cpd. detected detected detected detected detected detected detected Cyanide 1.0 mg/l or more not not not not not not not not detected detected detected detected detected detected detected detected Organic P Cpd. 1.0 mg/l or more not not not not not not not not detected detected detected detected detected detected detected detected PCBs 0.003 mg/l or more not not not not detected detected detected detected Tetrachloro- 0.1 mg/l or more not not not not ethylene detected detected detected detected Trichloro- 0.3 mg/l or more not not not not ethylene detected detected detected detected Cl Halogenated 5 mg/l or more not not not not organic detected detected detected detected substance Oily ingredient 5% or more not not not not not not not not detected detected detected detected detected detected detected detected *.sup.1KICET (Korea Institute of Ceramic Engineering and Technology) *.sup.2KCL (Korea Conformity Laboratories)

[0086] As shown in Table 2, measurements of all of the combustion dusts and combustion residues in both KICET and KCL were observed to fall behind the standards for designated wastes. Therefore, the SRF combustion dusts and combustion residues and CFBC combustion dusts and combustion residues used in the present disclosure are suitable for use as cement materials.

[0087] 1.9. Heavy Metal Content

[0088] The combustion dusts and combustion residues were measured for heavy metal contents, using the method of EPA 3051A: 2007, and the results are summarized in Table 3, below.

TABLE-US-00003 TABLE 3 Heavy Metal Sample Cl Pb Cu Cd As Hg Standard for use as alternative cement 20,000 150 800 50 50 2.0 material SRF combustion dust 128,000 785 5,620 33 N.D N.D SRF combustion residue 2,000 74 2,240 N.D N.D N.D CFBC combustion dust 28,800 N.D 265 N.D N.D N.D CFBC combustion residue 8,600 N.D 149 N.D N.D N.D Busan SRF 51,924 653 5,007 106 106  not  N.D. detected 12,342 not 4,564 19 19 not  N.D. detected detected 44 not 2,609 6  6 not  N.D. detected detected

[0089] As is understood from data of Table 3, the SRF combustion ash contained heavy metals at concentrations higher than the standards for use as alternative cement material according to the wastes control act. The SRF combustion residue was lower in chlorine and heavy metal contents than the SRF combustion ash, and contained Cu at a level higher than the standard for use as alternative cement material.

[0090] 1.10. Carbon Mineralization Method

[0091] For use in establishing a semi-dry carbon mineralization method for manufacturing a composite carbonate, as shown in FIG. 9, a batch-type CO.sub.2 reactor (size: 50l) was constructed and equipped with a real-time CO.sub.2 gas analyzer. In this reactor, CO.sub.2 was employed at a concentration of 60% by volume.

[0092] The capability of the reactor, which is calculated according to the following reaction scheme, can convert about 163 g of Ca(OH).sub.2 to about 200 g of CaCO.sub.3.

CaO+H.sub.2O.fwdarw.Ca(OH).sub.2  {circle around (1)}

Ca(OH).sub.2+CO.sub.2.fwdarw.CaCO.sub.3+H.sub.2O  {circle around (2)}

Example 2: Carbon Mineralization Using Slaked Lime

[0093] In Example 2, a preparative experiment for carbon mineralization of combustion ash was conducted to examine whether semi-dry carbonate can be produced from slaked lime by controlling an amount of water.

[0094] In this regard, water was added to 200 g of slaked lime in the batch-type CO.sub.2 reactor (CO.sub.2 concentration: 60 vol. %) and they were reacted at room temperature for 1 hour. Water was used in amounts of 0%, 25% (50 g), 50% (100 g), 75% (150 g), and 100% (200 g) (FIG. 10).

[0095] After water addition, characteristics of minerals were analyzed using Q-XRD (X PERT PRO, PANALYTICAL B.V.), and the results are depicted in FIG. 11.

[0096] As shown in FIG. 11, CaCO.sub.3 (calcite) was most abundantly converted from CaOH when water was added in an amount of 25%.

[0097] In addition, the characteristics of minerals identified by Q-XRD are schematically depicted in FIG. 12. As shown in FIG. 12, it was observed that the conversion was less likely to occur in the presence of larger amounts of water.

Example 3: Carbon Mineralization Using Combustion Ash

[0098] In Example 3, carbon mineralization was performed on combustion ash on the basis of the results of Example 2.

[0099] 3.1. Characterization of Carbon Mineralization According to Amount of Water

[0100] In the batch-type CO.sub.2 reactor (CO.sub.2 concentration: 60 vol. %), water was added to 200 g of SRF fly ash and they were reacted at room temperature for 1 hour. Water was used in amounts of 0%, 25% (50 g), 50% (100 g), 75% (150 g), and 100% (200 g).

[0101] After water addition, characteristics of minerals were analyzed using Q-XRD (X PERT PRO, PANALYTICAL B.V.), and the results are depicted in FIG. 13.

[0102] As shown in FIG. 13, CaOH started to convert into CaCO.sub.3 when water was added in an amount of 25% and was most abundantly converted at 75% of water.

[0103] In addition, the characteristics of minerals identified by Q-XRD were schematically depicted and changes of calcium-containing ingredients are given in FIG. 14. As shown in FIG. 14, effective conversion to CaCO.sub.3 was achieved when water was added in an amount of 25 to 100%.

[0104] 3.2. Characterization of Carbon Mineralization with Reaction Time

[0105] In the batch-type CO.sub.2 reactor (CO.sub.2 concentration: 10 vol. %), water was added to 200 g of SRF fly ash. The amount of water was fixed as 20%. They were reacted at room temperature for 1 min, 5 min, 10 min, and 30 min. Characteristics of minerals were analyzed by Q-XRD (X PERT PRO, PANALYTICAL B.V.).

[0106] The results are depicted in FIG. 15. As can be seen, the content of calcite in fly ash was 4.93% before the reaction and increased to 16.3% after 1 min of the reaction, indicating that a reaction is sufficiently induced for 1 min.

[0107] Furthermore, the characteristics of minerals identified by Q-XRD were schematically depicted and changes of calcium-containing ingredients are given in FIG. 16. As shown in FIG. 16, effective conversion to CaCO.sub.3 was achieved even after 1 min of the reaction.

[0108] 3.3. Characterization of Carbon Mineralization According to Carbon Dioxide Concentration

[0109] In the batch-type CO.sub.2 reactor, carbon dioxide was set to have a concentration of 10% by volume, 20% by volume, 50% by volume, and 100% by volume. In this condition, water was added at the fixed amount of 20% to 200 g of SRF fly ash. They were reacted at room temperature for 10 min. Characteristics of the minerals before and after the reaction were analyzed by Q-XRD (X PERT PRO, PANALYTICAL B.V.).

[0110] The results are given in FIG. 17. The content of calcite in fly ash was 4.93% before the reaction, increased to 15.21% at a carbon dioxide concentration of 10% and to 19.46% at a carbon dioxide concentration of 20%, with no significant difference in calcite content at a carbon dioxide concentration higher than 20%.

[0111] In addition, the characteristics of minerals identified by Q-XRD were schematically depicted and changes of calcium-containing ingredients are given in FIG. 18. As shown in FIG. 18, effective conversion to CaCO.sub.3 was achieved at a carbon dioxide concentration of 20 to 100% by volume.

[0112] Taken together, the data obtained above demonstrate that the mineralization of solid refuse fuel combustion ash or circulating fluidized bed combustion ash by water addition according to the method of the present disclosure can produce semi-dry composite carbonate that can be used in substitution for cement.

[0113] Accordingly, it should be understood that simple modifications and variations of the present disclosure may be easily used by those skilled in the art, and such modifications or variations may fall within the scope of the present disclosure.

INDUSTRIAL APPLICABILITY

[0114] The method for manufacturing a composite carbonate according to the present disclosure is a semi-dry method that overcomes all the limitations of conventional wet and dry methods, and the composite carbonate manufactured thereby can be utilized as an alternative ingredient in a concrete composition and as a solidifying agent or a filler in concrete.