A study of copper leaching from the tailings of the Karagaily (Republic of Kazakhstan) concentrating factory using an electric hydropulse discharge

Abstract

The method for using concentration plants tailings is proposed for the first time in this study. These tailings contain a number of valuable metals, such as Cu, Fe, Zn, etc., and are a potential raw material for obtaining concentrates of some elements. An electrohydropulse discharge was used to intensify the process of copper leaching and other metals. Ammonium bifluoride, the most effective of the ammonium salts used in copper leaching by the ammonization method, was chosen as the reagent. The influences of significant leaching parameters were studied and optimized using probabilistic deterministic planning of experiment. Based on the study findings, the following process conditions were found to be optimal: mass ratio of solid to liquid (S:L) of 1:1; Cu:F = 1:6; sulphuric acid concentration 40 g L-1; experiment duration 30 min; discharge voltage 10 kV and a leaching efficiency of 80-85 % could be achieved. Comparative features of tailings samples from the Karagaily (Republic of Kazakhstan) concentration plant were studied using X-ray diffraction (XRD), scanning electron microscope (SEM) and atomic emission spectral analysis. The study results showed that copper was maximally transferred to the aqueous phase.

Keywords

• chalcopyrite
• ammonium bifluoride
• water leaching
• copper tetra-amine sulphate