Reasearch on Optimum Mix Proportion Waste Rock-tailings Backfill Materials Based on Orthogonal Tests

To improve the problem of solid waste in phosphate mines, the research on the optimum mix ratio for cemented filling experiment of waste rock and phosphorus tailings was studied by orthogonal tests. Research on the influencing factors of uniaxial compressive strength, bleeding rate and slump constant for the filling body which was based on SPSS multivariate nonlinear regression analysis. Determining the optimal ratio and carry out semi-industrial tests to verify reliability. Results show that the filling to achieve optimal performance when the waste rock and tailings ratio is 6∶4, mass concentration is 78% and cement ratio is 280 kg/m³ for the filling body, the bleeding rate of filling bodyreaches the optimum and meets the pumping requirements of high fluidity, which meets the requirements of the mine filling process.