Recovery of non-ferrous metals from sulfide ores by the method of heap bioleaching on the example of Allarechensk technogenic deposit

Abstract

On the example of the Allarechensk technogenic deposit ore, the heap bioleaching method feasibility for the copper-nickel ores processing and non-ferrous metals recovery was considered. The content of metals in the initial ore sample was following: nickel – 2.42 %, copper – 0.75 %. The ore grinded to a size of -5+3 mm was irrigated with a solution containing a strain of Acidithiobacillus ferrivorans. The S:L ratio was 4:1, the flow rate was 0.1 mL/min. In pregnant solutions, the pH and ORP values were controlled, and the concentrations of ferrous and ferric iron, copper, and nickel ions were also measured. The experiment duration was 330 days, 8.9 % nickel and 6.1 % copper were recovered. The pathways for the metals extraction from pregnant solutions, as well as the utilization of bioleaching residue were considered.