Effect of metal-containing modifier compositions with sodium sulfide on the selective flotation of copper and zinc sulfides

The most efficient selective reagent modes for the flotation of a copper–zinc pyrite ore from one of the Ural deposits have been developed, based on the use of compositions of metal-containing reagent modifiers in combination with sodium sulfide. The study analyzed the most effective conditions for separating copper and zinc minerals from pyrite during the bulk flotation of copper–zinc ore, as well as the conditions for improving the selective separation of the bulk copper–zinc concentrate. The influence of reagent–modifier compositions introduced into the bulk flotation cycle on the process parameters of selective flotation of the bulk concentrate was evaluated. The results of fractional analysis of the floatability of copper, zinc, and iron minerals were presented, taking into account the flotation kinetics and the distribution of these minerals in the floated concentrate by fractions: poorly floatable, moderately floatable, and easily floatable. The reagent–modifier compositions used not only depressed pyrite flotation but also ensured efficient separation of copper and zinc minerals into individual concentrates. It was found that the most effective selectivity in flotation separation of copper and zinc minerals was achieved by introducing a composition of ferrous sulfate and sodium sulfide into the bulk copper–zinc flotation circuit in equal proportions (50 and 50 g/t). As a result, a copper–pyrite concentrate containing 12 wt. % Cu with a copper recovery of 74.45 % and a zinc concentrate containing 5 wt. % Zn with a zinc recovery of 73.68 % from the ore were obtained. Analysis of flotation kinetics showed that the introduction of this reagent mixture contributed to the highest flotation rate of copper, ensuring a maximum copper recovery to the froth (copper–pyrite) product of 86.74 %.