多元固废制备高强烧结透水砖及其性能研究

为充分利用尾矿资源，以多元固废（钒钛铁尾矿、金尾矿、页岩和水库底泥）为原料制备高强烧结透水砖，采用XRF、XRD及SEM研究了原料的物化特性，通过钒钛铁尾矿烧结产品的指标分析了其烧结特性，讨论了钒钛铁尾矿级配及粘结剂配比对透水砖性能的影响，确定了适宜的透水砖制备工艺参数。结果表明：①钒钛铁尾矿主要化学组成为SiO2、CaO、MgO，有利于形成辉石体系，促进结构的致密性，应用于烧结材料较为理想。颗粒表面粗糙，用作透水砖骨料时能够形成骨架结构，并在颗粒间形成一定孔隙，有利于砖体的透水性。②钒钛铁尾矿在不同烧结温度下颜色变化较大，随着烧结温度的升高，颜色由黄色逐渐转变为褐色，线膨胀率持续降低，质量损失率逐渐升高，堆积密度不断增大。③试验确定钒钛铁尾矿的适宜级配为1.18~4.75 mm占20%、0.60~1.18 mm占50%、0.15~0.60 mm占30%，适宜掺量78%；粘结剂的适宜配比为w（金尾矿）∶w（页岩）∶w（水库底泥）=2∶1∶1。④以钒钛铁尾矿为骨料制备透水砖，适宜的成型压力为25 MPa、烧结温度为1 080 °C、保温时间为90 min，此时透水砖抗压强度达到64 MPa，透水系数为0.062 cm/s，保水性为0.62 g/cm2，满足《透水路面砖和透水路面板》（GB/T 25993—2010）和《透水砖》（JCT 945—2005）的要求。

Preparation and Properties Study of High-strength Sintered Permeable Brick with Multiple Solid Waste

In order to make full use of tailings resources， multiple solid waste (vanadium-titanium iron tailings， gold tailings， shale and reservoir sediment) were used as raw material to the preparation of high strength sintered porous brick. XRF， XRD and SEM were obtained to study the physical and chemical properties of the raw materials， and sintering properties were analyzed through the vanadium-titanium iron tailings sintered products indicators. The effect of grains gradation of vanadium-titanium iron tailings and binder proportion on the properties of permeable brick were discussed and the suitable technological parameters for the preparation of permeable bricks were determined. The results showed that: ① The main chemical composition of vanadium-titanium iron tailings is SiO2， CaO and MgO， which is conducive to the formation of pyroxene system， promotion of structure compactness， indicating ideal materials for sintering materials. The grain surface is rough， and it can form skeleton structure and form certain pores between the grains when used as the aggregate of permeable brick， which is beneficial to the permeability of brick body. ② The color of vanadium-titanium iron tailings changes greatly at different sintering temperatures. With the increase of sintering temperature， the color changes from yellow to brown gradually， the linear expansion rate decreases continuously，the mass loss rate increases gradually， and the stacking density increases continuously.③ The suitable gradation of vanadium-titanium iron tailings is 1.18~4.75 mm accounting for 20%， 0.60~1.18 mm accounting for 50%， 0.15~0.60 mm accounting for 30%， and the suitable mixing amount is 78%. The suitable binder mass ratio of gold tailings， shale and reservoir sediment is 2∶1∶1. ④ The suitable forming pressure， sintering temperature and holding time are 25 MPa， 1 080 ℃ and 90 min， respectivly. At this time， the compressive strength of the permeable brick is 64 MPa， the permeability coefficient is 0.062 cm/s and the water retention is 0.62 g/cm2， which meet the requirements of Permeable Pavement Brick and Permeable Pavement Slab （GB/T 25993—2010） and Permeable Brick （JCT 945—2005）.