用细粒低硅铁尾矿制备三免砖

利用某种工业粉状废物制备廉价的无水泥固化剂,并以武钢矿业公司金山店铁矿细粒低硅铁尾矿为主要原料,研制MU25级的免烧、免蒸、免水泥建材砖(简称三免砖),考察了固化剂的掺量及其机械活化方式、试件的成型压力、化学外加剂种类及掺量、初期养护制度等工艺条件对制品抗压强度和耐水性的影响。试验结果表明:在成型压力为50 MPa条件下,混磨的固化剂掺量为25%,铁尾矿掺量为75%,有机早强剂A、防水剂B与固化剂掺量之比分别为0.02%、0.3%,初期养护温度为50℃、养护时间为36 h时,所制备的三免砖28 d的抗压强度和饱和抗压强度分别达到27.2 MPa和24.3 MPa,各项性能指标均能满足《JC/T422—2007非烧结垃圾尾矿砖》的要求。该研究为尾矿的大规模利用提供了一项投资小、效益高的技术。

Preparation of Bricks Made from Fine Low-silica Iron Ore Tailings without Sintering,Autoclave Curing or Cement

MU25 grade burning-free，autoclave curing-free and non-cement（“Three-free” for short)bricks were prepared by the fine low-silica iron ore tailing of Jinshandian Iron Mine，Wuhan Steel Mining Co.，Ltd.，as the main raw material，and the self-made non-cement made of industrial power waste as curing agent.The effect of the technical conditions such as dosage of curing agent and its mechanically milling facilities，molding pressure，the type and dosage of chemical admixture，the initial stage of curing regime on the compressive strength and water resistance of the products was investigated.The results show that the 28 d compressive strength and water absorption saturated compressive strength of the bricks can reach 27.2 MPa and 24.3 MPa respectively at conditions of forming pressure of 50 MPa，the curing agent of mixed grinding and the iron ore tailing of 25% and 75% respectively，dosage ratio of early strength agent A and waterproof ingagent B to curing agent of 0.02% and 0.3% respectively，early curing temperature of 50 ℃ and curing for 36 h.All properties meet the requirement in JC/T422-2007 standard “Unfired Bricks Made of Tailings”.The study provides a low investment and high profit technique for large scale utilization of such tailings.