铁尾矿基免烧透水砖的制备及其性能研究

Study on preparation and performance of iron tailings based non fired permeable bricks

以细铁尾矿粉、粉煤灰、磷石膏和矿渣微粉为胶凝材料,电石渣为激发剂,羧甲基纤维素钠水溶液为胶粘剂,采用半干压成型法,结合恒温恒湿养护工艺制备铁尾矿基免烧透水砖。结果表明:胶材体系中掺入水泥有利于免烧透水砖力学性能的提高,水泥熟料中的C2S、C3S等可促进细铁尾矿粉胶材体系进行水化反应,且蒸汽养护可提高免烧透水砖的力学性能,最佳配比为m(细铁尾矿粉)∶m(矿渣微粉)∶m(粉煤灰)∶m(磷石膏)∶m(骨料)=30∶30∶10∶30∶300,使用60℃蒸汽养护,制备出28 d抗折、抗压强度分别为2.72、24.5 MPa、透水系数为3.1×10^(-2)cm/s的免烧透水砖,性能符合GB/T 25993—2010《透水路面砖和透水路面板》的要求。

In this work,fine iron tailings powder,fly ash,phosphogypsum and slag powder are used as cementing materials,calcium carbide slag is used as activator,and sodium carboxymethyl cellulose aqueous solution is used as adhesive,non fired permeable bricks based on iron tailings were prepared by semi dry pressing and curing at constant temperature and humidity.The results show that:The addition of cement into the rubber material system is beneficial to the improvement of mechanical properties of unfired permeable bricks,C2S,C3S,etc.in cement clinker promote the hydration reaction of fine iron tailings powder rubber material system.And steam curing can improve the mechanical properties of unburned permeable bricks.The optimal ratio is fine iron tailings powder∶slag micropowder∶fly ash∶phosphogypsum∶aggregate=30∶30∶10∶30∶300.Using steam curing at 60℃,non fired permeable brick with the 28 day flexural strength of 2.72 MPa,compressive strength of 24.5 MPa,and permeability coefficient of 3.1×10^(-2 )cm/s was prepared,its performance meet the requirements of GB/T 25993—2010"Permeable paving bricks and permeable paving flags".