WANG Chang-long1,2, LIU Shi-cang1, ZHENG Yong-chao3, YANG Jian1, CUI Xiao-wei2, DI Yan-qing2
(1. School of Civil Engineering, Hebei University of Engineering, Handan 056038, China;
2. Shaanxi Key Laboratory of Comprehensive Utilization of Tailings Resources, Shangluo University, Shangluo 726000, China;
3. State Key Laboratory of Solid Waste Reuse for Building Materials, Beijing 100041, China)
Abstract: For comprehensive utilization of solid wastes, the autoclaved aerated concrete (AAC) was successfully prepared by using calcium carbide residue and iron ore tailings as the main raw materials and aluminum powder as gas evolution agent. The fineness and content of calcium carbide residue, curing temperature of static stop on the properties of AAC were investigated, and hydration products of ACC were analyzed by XRD. Results show that ACC has bulk density of 579 kg/m3 and compressive strength of 4.47 MPa in the case of specific surface area of 320 m2/kg and content (mass percent) of 26% of calcium carbide residue, and curing temperature of static stop is 70 ℃. When the major components Ca(OH)2 in calcium carbide residue dissolves in water, the heat is generated due to hydration reaction. However, the amount of heat is not enough to promote the strength of AAC. Hence, it is important to raise the curing temperature of static stop until the reaction energy obtained. The XRD analyses show that the main crystalline phases are 0.9 nm tobermorite, 1.1 nm tobermorite, and 1.4 nm tobermorite.
Keywords: calcium carbide residue; iron ore tailings; autoclaved aerated concrete; tobermorite
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ACTA MINERALOGICA SINICA Vol. 35, No. 3, 2015, Page 373-378
