Experimental study on properties of solidified tailings using phosphorous solid waste-based cementitious materials

This study employed tailings from a phosphate mine in Yunnan as aggregates, combined with a fully phosphorous solid waste-based cementitious material to produce solidified tailings. It aims to investigate the effects of concentration and mix ratio on the impermeability grade, shear strength （cohesion and internal friction angle）, and compressive strength of the solidified tailings. During the solidification process, under the same mix ratio （m （cementitious material）︰m （phosphate tailings））, increasing the concentration （from 72 % to 85 %） significantly enhanced the performance of the solidified tailings. Under the same concentration conditions, reducing the mix ratio （from 1︰10 to 1︰20） led to a significant deterioration in the performance of the solidified tailings, with the deterioration rate accelerating nonlinearly as the mix ratio decreased. Nonlinear regression analysis further confirmed that the effects of concentration and mix ratio on impermeability grade, shear strength （cohesion and internal friction angle）, and compressive strength exhibit significant nonlinear characteristics. This research provides important experimental data and theoretical support for the resource utilization of phosphate tailings, contributing to their application in areas such as mine backfilling and alleviating the environmental and safety pressures associated with phosphate tailings storage.