INVESTIGATION OF THE SULFATE LEACHING PROCESS OF SULFATED RESIDUE OBTAINED FROM COPPER SULFIDE CONCENTRATE

Abstract

It is widely recognized that several methods exist for processing copper concentrates. In most cases, the processing of concentrates begins with oxidative roasting, or as it is often referred to, “dead roasting,” which results in the formation of calcine, whose primary components are metal oxides. Subsequently, the calcine undergoes the conventional “smelting-converting-fire refining-electrolytic refining” sequence to yield pure copper.

However, during concentrate processing, attention is almost exclusively focused on the main components of the concentrates, while little consideration is given to the recovery of other valuable metals such as zinc, lead, iron, and others. Traditional pyrometallurgical processes generally do not address this issue, as these metals either transition into the slag phase or remain in metallic by-products in various compound forms. In the conventional pyrometallurgical processing of concentrates, iron is completely disregarded, as it irreversibly passes into the slag.

For this reason, it is essential to implement technological principles that enable the comprehensive recovery of valuable elements contained in the concentrates at various stages of metallurgical processing.

   The process of sulfate leaching of sulfated residue obtained from copper sulfide concentrate is presented. The objective is to transfer the valuable metals contained in the sulfated residue into a solution for their subsequent selective and comprehensive recovery. The sulfate leaching of the residue was conducted in a 9% sulfuric acid solution at a temperature of 80°C under continuous stirring conditions.

It has been shown that copper, zinc, and iron are almost completely extracted during the leaching process: the extraction rate of copper is 99.6%, zinc - 99.5%, and iron - 75.7%. The remaining iron transitions into the solid residue. Lead sulfate remains entirely in the solid residue after acid leaching. Insoluble sulfide silver also passes into the residue because it does not oxidize during the roasting process and, as a result, does not dissolve.