Research on modeling the technology of processing anthropogenic old tailings of Primorsky Concentrating Factory

The possibility of processing old tailings of the Primorsky Concentrating Factory (PCF) has been assessed. The average mass fraction of WO3 is 0.08%, Cu is 0.052%, the average content of Au is 0.38 ppm, Ag is 1.1 ppm. The grain size of scheelite and chalcopyrite is from 0.03 mm and below. Basically, intergrowths of scheelite are in quartz, less often is in pyroxene, chalcopyrite is in pyrrhotite, less often is in quartz. The results of experimental studies of the washability of secondary mineral material using flotation and gravity beneficiation methods are presented. The possibility of intensifying the flotation process of concentration using a Pneuflot® flotation machine was investigated. The recovery of scheelite at the same degree of concentration using a Pneuflot® flotation machine is 16.5% higher compared to the standard mechanical flotation machine, mainly due to the more efficient flotation (1.5 times) of sludge (-15+0 μm). Flotation of the sand fraction of old tailings (SFOT) in a Pneuflot® flotation machine showed an opportunity of scheelite recovery into enriched concentrate of rough flotation from -44+15 microns material by 82%, and -15+0 microns (from sludge) by 75% of those classes, the case being for the mechanical machine (volume 3 l) – 77% and 49% of those classes, respectively. The content of the obtained flotation concentrate corresponds to the quality of the feed of rough scheelite flotation at PCF (at a concentration degree of 8.5 in the enriched product, the scheelite recovery was 69%), enabling to integrate it to the technological scheme of PFC. According to the combined gravity-flotation concentration scheme, a conditioned scheelite concentrate with a mass fraction of 70.9% WO3 was obtained, throughout recovery being 57.3%.