关键词: 细粒低硅铁尾矿, 三免砖, 外加剂, 抗压强度, 耐水性

Abstract: 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.

Key words: Fine low-silica iron ore tailing, Three-free brick, Admixture, Compressive strength, Water resistance