碱矿渣水泥及其对铅锌尾砂的固化效果

通过水泥净浆强度试验和水泥-尾砂浆体流动性及其固化体的强度试验，确定了适宜于尾砂固化的碱矿渣水泥的较好的配合比，和尾砂固化中碱矿渣水泥的适宜掺量。采用低模数水玻璃，按14%与矿渣粉配合得到的碱矿渣水泥，可以获得较好的净浆硬化体抗压强度，最高可达3 d 69.6 MPa，7 d 84.0 MPa，28 d 91.8 MPa。在水泥-尾砂浆体固含量相同的情况下，碱矿渣水泥-尾砂浆体的流动性明显优于硅酸盐水泥-尾砂浆体的流动性，碱矿渣水泥-尾砂固化体强度高于硅酸盐水泥-尾砂固化体强度，尤其是后期强度更加明显。而在控制尾砂浆体流动度相同的情况下，前者固含量可以高于后者2%。SEM对水泥-尾砂固化体内部微观结构的观察表明，碱矿渣水泥-尾砂固化体内部结构显示出明显的胶结特征。固化体内部孔结构的MIP测定结果也表明，碱矿渣水泥用量增加时固化体总孔隙率减小，孔隙中大孔比例减少，小孔比例增加。综合水泥-尾砂浆体流动性和固化体强度两方面的试验结果，可以认为碱矿渣水泥比普通硅酸盐水泥更适合于用作尾砂胶结材料。

Caustic Slag Cement and Its Fixation Effect for Lead-Zinc Tailings

Through the tests on the strength of pure cement, the fluidity of cement-tailing slurry and its solidified body, the suitable proportioning ratio of the caustic slag cement and its addition for tailing solidification were determined. The adoption of caustic slag cement prepared by low modulus sodium silicate (14%) and slag powder could obtain good compressive strength of the hardened body of the pure slag cement, which was as high as 69.6 MPa after three days and 84.0 MPa after seven days and 91.8 MPa after 28 days. When the slurry had the same amount of caustic slag cement and tailings, its fluidity was evidently better than that of the slurry consisting of silicate cement and tailings and the strength of its solidified body was also higher than that of the latter, especially after a longer time of solidification. When the fluidity of both slurries was controlled to be the same, the solid content of the former could be higher than that of the later. The investigation of the internal microscopic structure of the cement and tailing solidified body by SEM indicated an evident cementing character in that of the caustic cement and tailings. MIP measurement of the internal pore structure of the solidified body shows that the total pore rate of the solidified body was reduced when the dosage of the caustic slag cement was increased, with the large pore proportion reduced and the small pore proportion increased. It can be considered, through the comprehensive investigation of the fluidity and the strength of the solidified body of cement and tailing slurry, that caustic slag cement is more suitable than common silicate cement to be used as the cementing material for tailings.