An Integrated Approach to Gold Extraction from Man-Made Raw Materials with High Carbon Content

Abstract

This study presents the results of investigating the effect of reverse carbon flotation on gold recovery from secondary technogenic raw materials—aged sorption tailings with a high carbon content and refractory forms of gold. Direct cyanidation of the initial material showed low efficiency (up to 13% gold recovery) due to the pronounced preg-robbing effect. Comparative flotation tests demonstrated that the highest gold losses occurred during conventional sulfide flotation using xanthate. Additional grinding of the material increased gold extraction during cyanidation but was accompanied by higher losses during flotation. The application of reverse carbon flotation with kerosene and frother effectively removed the carbonaceous fraction and reduced gold adsorption from the solution. Further oxidation with trichloroisocyanuric acid enhanced the gold recovery up to 78.25%. Biological oxidation using Acidithiobacillus ferrooxidans also increased the gold recovery from both the initial material and the products of reverse flotation.