Investigation of the processes of copper ions transition into a solution from oxide and sulfide compounds under the influence of organic complexing agents

Abstract

The article describes the results of studying of the process of copper leaching from model grounds containing 0.02 % of copper oxide or copper sulfide, with solutions of natural and chemically modified complexing agents. The total amount of one ground sample was 500 g. The model grounds were placed in columns, and the solutions of complexing agents were passed through the columns at a given rate. Sodium humate, sulfonated and oxidized humic acid, native and oxidized fulvic acid, and sodium lactate were studied as leaching agents. It is shown that solutions of all reagents with a concentration of 0.01 % can produce a transition of copper into the solution from both the oxide and sulfide mixtures. It was established that oxidized and native fulvic acids and sodium lactate are most effective for copper extracting. For oxide copper minerals, the most effective complexing agent is the lactate ion, and an oxidized derivative of fulvic acid has a little lower efficiency. Further, less effective agents are the sulfonated humic derivative and the native fulvic acid which have approximately equal effectiveness. The sodium humate is less active and the oxidized humic derivative has lower efficiency. In the case of sulfide minerals, the most effective complexing agent is the oxidized derivative of fulvic acid. The lactate ion, the sulfonated humic derivative and the native fulvic acid are a little less effective agents. The sodium humate and the oxidized humic derivative have comparatively low efficiency. By the mathematical processing of kinetic data, the rate constants of copper leaching processes from model grounds were estimated. The values of the found constants are in the range from 1.05·10-7 to 1.28·10-7 s-1. The kinetic curves for the transferring of copper ions to the solution under the action of complexing agents are characterized by a relatively small transition period and fast reaching concentrations which are close to equilibrium ones.