Effects of Different Calcining Temperatures on the Properties of Ceramsite Prepared by High-carbon Gasification Slag

Abstract

The structure and characteristics of high-performance lightweight aggregates produced by high-carbon gasification slag were investigated by X-ray diffraction, scanning electron microscopy, thermogravimetry/differential thermogravimetr, differential scanning calorimetry-Fourier transform infrared, and mercury intrusion porosimetry, respectively. The experimental results show that the ceramsite undergoes two weightless stages in the calcining process. With the increase in the calcining temperature, a large number of pores are formed inside the ceramsite, its structure becomes denser, but the calcining temperature band of the ceramsite becomes narrow. The crystalline phase of the ceramsite changes at different calcining temperatures and the mineral phase changes from the earlieralbite, quartz, oligoclase, hematite, etc, to a silica-aluminum-rich glass phase. The 1 130 °C is a more suitable calcining temperature, and the cylinder compressive strength of ceramics is 11.59 MPa, the packing density, apparent density, porosity, and water absorption are 939.11 kg/m³, 1643.75 kg/m³, 28.11%, and 10.35%, respectively, which can meet the standards for high-strength lightweight aggregates.

Keywords

high-carbon gasification slag / ceramsite / concrete / physical property

References

[1] Li XF. Key Technology of Coal Chemical Gasification Process and Equipment[J]. Shanxi Chemical Industry, 2018, 38: 135-139.

[2] Yin HF, Tang Y, Ren Y, et al. Study on the Characteristic and Application Gasification Slag from Texaco Gasifier[J]. Coal Conversion, 2009, 32(4): 30-33.

[3] Acosta A, Iglesias I, Aineto M, et al. Utilization of IGCC Slag and Clay Steriles in Soft Mud Bricks (by pressing) for Use in Building Bricks Manufacturing[J]. Waste Management, 2002, 22(8): 887-891.

[4] Wagner NJ, Matjie RH, Slaghuis JH, et al. Characterization of Unburned Carbon Present in Coarse Gasification Ash[J]. Fuel, 2008, 87(6): 683-691.

[5] Matjie RH, Van AC. Mineralogical Feature of Size and Density Fractions in Sasol Coal Gasification Ash South Afraca and Potential By-products[J]. Fuel, 2008, 87(89): 1 439-1 445.

[6] GAO JG, MA YL, LIU RJ. Comprehensive Utilization and Benefit Analysis of Coal Slurry Gasification Ash[J]. Energy Conservation and Environmental Protection, 2014: 72–73

[7] Zhao YB, Wu H, Cai XL, et al. Research on the Basic Characteristics of Coal Gasification Residues[J]. Clean Coal Technology, 2015, 3(21): 110-114.

[8] Zhao YB, Wu HJ, Zhang XB, et al. Fabrication of Porous Ceramic from Coal Gasification Residual[J]. Clean Coal Technology, 2016, 22(5): 7-11.

[9] Oats W J, Ozdemir O, Nguyen AV. Effect of Mechanical and Chemical Clay Removals by Hydrocyclone and Dispersants on Coal Flotation[J]. Minerals Engineering, 2010, 23(5): 413-419.

[10] Anagnostopoulos IM, Stivanakis VE. Utilization of Lignite Power Generation Residues for the Production of Lightweight Aggregate[J]. Journal of Hazardous Materials, 2009, 163(1): 329-336.

[11] Liu X, Chia KS, Zhang MH. Water Absorption Permeability and Resistance to Chloride-ion Penetration of Lightweight Aggregate Concrete[J]. Constr. Build. Mater., 2011, 25(1): 335-343.

[12] Yang YH, Wei ZA, Chen YL, et al. Utilizing Phosphate Mine Tailings to Produce Ceramisite[J]. Journal of Wuhan University of Technology-Mater. Sci. Ed., 2020, 35(1): 140-146.

[13] Cheeseman CR, Virdi GS. Properties and Microstructure of Light-weight Aggregate Produced from Sintered Sewage Sludge Ash[J]. Resour. Conserv. Recycl., 2005, 45(1): 18-30.

[14] Karas KP, Klein M, Hupka J, et al. Utilization of Shale Cuttings in Production of Lightweight Aggregates[J]. J. Environ. Manage, 2019, 231(1): 232-240.

[15] Liu TY, Tang Y, Han L, et al. Recycling of Harmflu Waste Lead-zinc mine Tailings and Fly Ash for Preparation of Inorganic Porous Ceramics[J]. Ceram. Int., 2017, 43(6): 4 910-4 918.

[16] Wang FZ, Li M, et al. Improvement of the FRP Sheet Bonded to Concrete Substrate by Silane Coupling Agent[J]. Journal of Wuhan University of Technology-Mater. Sci. Ed., 2018, 33(1): 117-123.

[17] Bassani M, Diaz G, Meloni F, et al. Recycled Coarse Aggregates from Pelletized Unused Concrete for a More Sustainableconcrete Production[J]. J. Clean. Prod., 2019, 20(9): 424-432.

[18] Bostanci SC, Limbachiya M, Kew H. Use of Recycled Aggregates for Lowcarbon and Cost Effective Concrete Construction[J]. J. Clean. Prod., 2018, 18(9): 176-196.

[19] M O’Farrell S, Wild BB. Pore Size Distribution and Compressive Strength of Waste Clay Brick Mortar[J]. Cem. Concr. Compos., 2001, 23(1): 81-91.

[20] Xu G, Zou J, Li G. Effect of Sintering Temperature on the Characteristics of Sludge Ceramsite[J]. J. Hazard. Mater., 2008, 150(2): 394-400.

[21] Zhao LH, Li Y, Zhang LL, et al. Effects of CaO and Fe₂O₃ on the Microstructure and Mechanical Properties of SiO₂-CaO-MgO-Fe₂O₃ Ceramics from Steel Slag[J]. ISIJ Int., 2017, 32(2): 15-21.

[22] Zhao LH, Li Y, Jiang F, et al. Effects of Composition Changes on the Sintering Properties of Novel Steel Slag Ceramics[J]. Ceram. Trans., 2016: 45–51

[23] Liu MW, Xu GR, Li GB. Effect of Fe₂O₃ on the Characteristics of Lightweight Aggregate Made from Sewage Sludge and River Sediment[J]. J Harbin Institute of Technology, 2012, 44(10): 10