Optimization of the Filling Mixture for the Tashtagol Mine

The relevance of the work is due, on the one hand, to the need to solve the problem of subsidence of the earth's surface in areas of underground mining, and, on the other, to the placement of a significant amount of ash and slag waste from coal-fired thermal power plants and boiler houses, waste from the mining and metallurgical industries. This paper describes the operation of the laying complex at the Tashtagolsky mine of JSC EVRAZ ZSMK JSC. The typical composition of the filling mixture is presented, the most expensive components of which are cement from the Topkinsky cement plant and blast furnace granulated slag delivered from the metallurgical plant in Novokuznetsk. The conducted research has established the possibility of optimizing the composition of the filling mixture by replacing cement and granular slag with fly ash from the West Siberian thermal power plant. The preparation of the mixture was carried out ina laboratory rod mill with the selection of the grinding mode of the starting materials. In experiments, the required values of fineness (no more than 5% of the residue on the sieve No. 0.14) and mobility of the filling mixture were achieved by adding water. The mobility of the mixture was determined on a Souttard device, a shaking table and a standard cone. A method for calculating an industrial rod mill to replace ball mills installed at the mine is presented. Samples of the hardening bookmark were prepared from the prepared in laboratory conditions. The results of studies of the hardening bookmark samples showed the necessary strength at a holding time in conditions simulating mining for more than 90 days (more than 4 MPa), while the density of the laying mixture was more than 2 g/cm3when replacing 50 % with fly ash.