关键词: 钒钛铁尾矿, 水库底泥, 颗粒级配, 成型压力, 烧结温度, 保温时间, 透水砖性能

Abstract: 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）.

Key words: vanadium-titanium iron ore tailings, reservoir sediment, grains gradation, moulding pressure, sintering temperature, holding time, properties of sintered permeable brick