Experimental Study on Recovery of Cyanide Tailings Slurry by Membrane Separation in a Gold Mine

Abstract

In view of the difficulty in recovering valuable metals and cyanides from cyanide tailings pulp in gold mines, the laboratory exploratory test of recovering gold and silver from the tailings pulp produced by a CIP process was carried out by using the technology of “solid-liquid separation + membrane separation and purification + adsorption and recovery of gold and silver by activated carbon”. The results showed that the cyanide tailings slurry was separated by solid-liquid in the laboratory and stabilized by chemicals, and the dry slag was identified as a general solid waste according to the results of the identification standard for hazardous waste leaching toxicity GB5085.3-2007. The screened reverse osmosis membrane test showed that 95% of the permeate water recovery rate were obtained. The concentration of cyanide in membrane concentrate water reached 807.9 mg/L, the concentration of copper, gold and silver reached 0.43 mg/L and 3.91 mg/L respectively after being concentrated from below the detection limit, and the concentration was 19.9, 14.3 and 18.6 times respectively. The adsorption test of membrane concentrate water by activated carbon showed that gold, silver and copper were absorbed in membrane concentrated water, the adsorption rates reached 99.76%, 96.16% and 9.09% respectively, which facilitated the subsequent selective recovery of gold and silver. The recovery of valuable metals and cyanide from cyanide tailings slurry by the process of “solid-liquid separation + membrane separation and purification + adsorption and recovery of gold and silver by activated carbon” had a good effect.