Improving the technology of copper-zinc ore beneficiation of a Uralian-type pyrite deposit

Abstract

Introduction and research objective. Copper-zinc ore of pyrite deposits of the Uralian type are refractory. Difficulties in beneficiation are due to their material composition: fine coarseness and emulsion impregnation of ore minerals in each other, a large amount of flotation-active pyrite, a high content of finely dispersed and submicroscopic gold in sulfides, etc. In the course of pyrite ore processing at dressing mills, 83–91% of copper and 10–45% of gold are extracted into copper concentrates, and 46–78% of zinc and 5–15% of gold are extracted into zinc concentrates. Increasing the process performance of pyrite deposit ore processing is a promising and urgent task. Methods of research included copper-zinc pyrite ore material composition study through quantitative chemical analysis, chemical phase analysis for the forms of copper, zinc, gold and silver compounds, and mineralogical analysis. Technological studies were carried out by flotation and gravity methods using a centrifugal concentrator and a concentration table. Conclusions. In the course of pyrite deposit copper-zinc ore beneficiation at the dressing mill, the effect of circulating concentration of gold in the coarse copper concentrate regrinding cycle was established. The results of studies on the centrifugal concentration of gold in a centrifugal concentrator with further secondary cleaning of its heavy fraction on a concentration table show the possibility of obtaining a gravity product with a mass fraction of gold up to 200 g/t under its operational extraction up to 29%. It was noted that the integrated flotation-gravity technology for copper-zinc ore beneficiation will increase the through extraction of gold into marketable mineral products by more than 1.5%. The use of a combination of butyl potassium xanthate and FRIM-2920 reagent-collector in the copper-zinc pyrite ore flotation technology contributes to increased extraction of copper and gold into copper concentrate by 0.87% and 3.22%, respectively, and zinc into zinc concentrate by 0,4%. Increasing the pulp temperature in the zinc flotation cycle to 40–45 °C and returning the control zinc flotation concentrate and tailings from the first cleaning flotation of zinc to the II main zinc flotation allows increasing the mass fraction of zinc in the zinc concentrate from 48.5 to 51.1% under a simultaneous increase in the extraction of zinc into zinc concentrate from 62.6 to 65.6%.