Possibility of implementation of dry technology of gold-bearing ores roughing: case study of “Gurbey” deposit

The aim of the research is to identify the ability/feasibility of dry roughing of ore taking as the example “Gurbey” deposit in Irkutsk Region and to develop a rational scheme for processing ores containing free gold. Studies of the dry processing technology of gold-bearing ore at “Gurbey” deposit with the initial weight of 1,123.8 kg were carried out by semi-industrial plants: the DKD-300 combined shock impact crusher, the CMVU-800 centrifugal mill and the POS-2000 air separator developed by CNMI SD RAS. The sample was subjected to two cycles of crushing and four cycles of grinding followed by pneumatic separation. The circulating load is class +12 mm after the DKD-300 crusher, and for the mill, all screening products are +3 mm, as well as the products of classification -3 + 1 mm of the POS-2000 concentrate. As a result of treatment of the concentration products, 23.93 grams of free gold was recovered (concentration on tables: control, recleaning, concentration of the Mosely minerals by analyzer, magnetic separation, heavy medium separation on bromoform). At the same time, it was established that gold from the ore with initial size of 150 mm can be completely stripped and recovered with the POS-2000 air separator with a particle size of up to 100 microns. At the same time gold extraction into the primary concentrate is up to 60%. Based on the results of the research, a basic scheme for dry roughing of “Gurbey” ore containing “free” native gold was developed using the ore treatment devices: RD-MDV-900, DKD-300 crushers, CMVU-800 centrifugal mill and POS-2000 air separator. The technological scheme is fundamental for gold-bearing ores containing "free" gold of fineness over 100 microns