关键词: 固体充填, 胶凝材料, 矿粉, 充填效率, 顶板管理

Abstract: In order to solve the problems of high filling cost and low filling efficiency of the coal mining under buildings,water bodies and railways, we mainly use mineral powder, a low-cost hydraulic cementitious material, supplemented by a small amount of gypsum and silicate clinker, an early-setting, low-cost cementitious material is obtained that it is suitable for high-efficiency solid backfilling. We also analyzed the size grading of gangue and the curing mechanism of the cementitious material, the optimal ratio of cementitious materials is obtained through designing orthogonal experiments, when gypsum content is 5%, cement clinker content is 25%, and mineral powder content is 70%, the filling body can be demoulded in a short time, it shows that the degree of hydration reaction of the cementitious material is the best at this content, the active ingredients of the mineral powder can react in the early stage to form hydraulic ettringite (AFt), which promotes the formation of the strength of the filling body, The 7d and 28d strength of the filling body can reach 3.48MPa, 5.11 MPa After curing, it is slightly lower than the 7d and 28d forming strength of 425# sulphoaluminate double fast cement, but it has obvious advantages in cost. Combined with industrial applications, we analyze the actual filling effect, the working resistance of the hydraulic support and the observation data of ground subsidence, it shows that the cementitious material plays a positive role in improving filling efficiency and strengthening roof management.