Development of a technology for purifying the liquid phase of a tailings storage facility from arsenic and cyanides

Laboratory studies were conducted to determine the optimal reagent dosages for the treatment of effluent from the tailings storage facility via sorption. It was established that the best results for the removal of dissolved arsenic ions and cyanides from the aqueous phase are achieved by dosing an oxidizing agent in the form of a 12.5% solution of FeSO4 at a rate of 1.0–1.5 ml/dm³, while maintaining a pH level between 7.2 and 7.5, followed by the application of Metalsorb FZ at a dosage of 0.5 ml/dm³. The feasibility of recovering gold from the resultant precipitate was confirmed. It was observed that after treatment of the effluent for discharge into the flotation tailings storage facility with a 15% solution of FeSO4 at a rate of 1 dm³/m³, the aqueous phase acquired color. Experiments were conducted to assess the variation in water color in relation to the dosage of iron sulfate, ranging from 1.0 to 3.0 ml/dm³. It was concluded that the concentration of arsenic after treatment solely with FeSO4 increases sixfold, while the concentration of iron rises fourfold. A Technological Regulation for the treatment of accumulated water from the sorption tailings storage facility at JSC “Altyntau Kokshetau” has been developed and presented for discussion. The results provided demonstrate the technological feasibility of reducing harmful impurities, specifically arsenic and cyanide compounds, in the liquid phase of the sorption tailings storage. A technological scheme for the purification of arsenic and cyanides from the effluent of the sorption tailings storage has been proposed. The control of the technological process for the treatment of the effluent and the safety conditions when working with the proposed reagents have been examined.