以电石渣铁尾矿为原料制备加气混凝土的实验研究

Autoclaved Aerated Concrete Prepared with Calcium Carbide Residue and Iron ore Tailings as Raw Materials

为综合利用固体废弃物,本文以电石渣和铁尾矿为主要原料,铝粉膏作为发气剂开展制备加气混凝土的实验研究,探讨电石渣的粒度、掺量和静停养护温度对加气混凝土物理力学性能的影响,并利用XRD分析了加气混凝土的水化产物。结果表明:当电石渣比表面积为320 m2/kg,掺量为26%(质量百分数),静停养护温度为70℃时,可以制备出绝干密度为579 kg/m3,抗压强度为4.47 MPa加气混凝土制品。电石渣中Ca(OH)2溶于水后,放热量低,不能满足加气混凝土生产的需求,需要提高外部静停养护温度,满足加气混凝土热值需要。XRD分析显示,所制备的加气混凝土中主要结晶相是0.9 nm托贝莫来石、1.1 nm托贝莫来石和1.4 nm托贝莫来石。

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.