Hydrometallurgical Processing of Gold-Containing Ore and its Enrichment Products

Abstract

This research focuses on the hydrometallurgical processing of auriferous ores and their processing products, namely, flotation and gravity concentrates. The main valuable component of an ore sample of any deposit is gold. The gold content should be in the range of 11.11–12.87 g/ton. The main rock-forming minerals of the original ore are quartz (60.1%), quartz–chlorite–micaceous aggregates (3.8%), and carbonates (7.1%). In this study, original ores of various sizes were treated by direct and sorption cyanidation under various leaching modes, and the results obtained were presented. The original ore was leached with various concentrations of sodium cyanide (NaCN) in solution to study the effect of the complexing agent concentration on gold recovery. Data on the dynamics of leaching revealed that a decrease in the concentration of NaCN in solution from 0.2% to 0.03% leads to a decrease in gold recovery in solution by 26.81%. Original ores could easily be processed using hydrometallurgical methods. The recovery of gold with a coarseness of 95% − 0.045 mm from the original ore averaged 97.77%. This work features a full range of studies on the hydrometallurgical processing of concentrates and gravity tailings, as well as the effects of flotation concentration of gold recovery. The gravity concentrate is resistant to intensive cyanidation (i.e., only 67.07% gold recovery into the solution). The use of 1% lead nitrate (PbNO3) during intensive cyanidation could reduce the refractoriness of the concentrate and increase the recovery of gold into the solution by up to 94.35%. The total gold recovery from gravity concentrate is 98.71%, and the recovery of gold by cyanidation of gravity tailings with a cyanide concentration of 0.2% averages 96.57%. The recovery of gold during leaching of the flotation concentrate at the original size (95.5% − 0.074 mm) and a cyanide concentration of 0.2% is 96.64%. A decrease in the size of the flotation concentrate from 95.5% − 0.074 mm to 95% − 0.02 mm leads to a decrease in gold recovery by 35.43% because of the strong chemical activation of the material during grinding.