Characteristics Variation of Tailings Using Cemented Paste Backfill Technique

Cemented paste backfill has been proposed in the mining industry for managing metal mill tailings. Low sulfide tailing (0.49 wt%) samples were prepared into different cemented pastes that were mixed with flocculants (polymerized aluminum chloride). The best mixing proportions of tailings, binder, flocculant, and filling structure (containing 0.5 wt% of ordinary Portland cement in one paste layer, 100 g/L polymerization aluminum chloride) were determined through leaching experiment. The addition of polymerization aluminum chloride improved the mechanical property of the paste. The strength of the cemented pastes by adding 100 g/L flocculant met the requirement of mine backfill. The cemented paste could also fix heavy metals, as shown in the paste leachate analysis of copper (Cu, about 0.01-0.08 mg/L of concentration) and chromium (Cr, about 0.03 mg/L of concentration). In summary, results from this study demonstrate that tailings can be managed by cemented paste backfill technique, preventing its contamination of the environment.