关键词: 碱矿渣水泥, 尾砂, 回填, 流动性, 固化体

Abstract: 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.

Key words: Caustic slag cement, Tailings, Backfilling, Fluidity, Solidified body