Optimal design and experimentation of full tailings and cementitious materials: a case study of a lead-zinc mine in China.

As mineral resources become increasingly scarce and environmental awareness grows, mining companies urgently need cost-effective and environmentally friendly filling methods for mines. The use of ultrafine tailings combined with various binders at different ratios plays a key role in determining the rheological properties and mechanical strength of cemented paste backfill. This paper provides parameter basis for the design of a mine filling system, firstly, different filling materials and proportions were selected, and basic physicochemical property tests, along with cementitious material analysis, were conducted to determine the key physical and chemical properties and mineral composition of the materials. Next, the rheological properties, transport performance, and bleeding characteristics of the filling slurry were tested to assess the feasibility and process requirements for self-flow transport through pipelines. The results indicated that the transportation performance of the slurry was better when gelling powder was used as the binder. Finally, the compressive, shear, and tensile strengths of the filling blocks were tested under varying slurry mass concentrations and cement-tailings ratios at different curing times. This helped identify the optimal filling concentration and proportions needed to meet the strength requirements of the filling structure. The final study found that the sample with a cement-tailings ratio of 1:6, a mass concentration of 68%, and a gelling powder as the binder reached the strength requirements for mine filling after 28 days. This research offers valuable insights for other mining companies seeking to implement similar environmentally sustainable and cost-effective filling technologies, promoting wider adoption and advancements in the field.