Study of gold-bearing ores material and mineralogical composition in Lower Angara region

Abstract

In connection with the involvement in new deposits exploitation, represented by refractory oxidized ores with a fine-dispersed phase and valuable component low content, there have been trends in the processing of this type of raw material. The alluvial gold-bearing sands of Lower Angara region are of practical interest. The results of the material and mineralogical composition of gold-bearing ores made it possible to establish that most rock fragments are quartz-mica schists, which are dilapidated by weathering up to 15% of the sample mass and clay inclusions. Ore by 61.5% is presented with grain size of more than 20 mm. Gold is distributed almost evenly by size class. Basically, gold is found in intergrowths with quartz, mica, pyrite, and clay components. The size of the gold grains ranges from 0.03 to 0.05 mm to several microns. The content of the valuable component was about 3-5%. The result of gravity concentration of the original ores showed the possibility of obtaining gravity concentrates with a metal content of 220-250 g/t, with extraction up to 93-95% and obtaining tailings from 0.3-0.5 g/t, followed by leaching of cyanide and sulfur-alkaline solutions. The extraction of the valuable component into the solution was 80% and 98%, respectively. The results obtained indicate the possibility of processing these types of ores in Lower Angara region.