China Nonferrous Metallurgy

A low grade super large refractory gold deposit belongs to Carlin type gold deposit. The gold grade is low and the ore is difficult to separate. The comprehensive benefit is not ideal by using conventional beneficiation process and pre-oxidation technology. A research institute carried out process mineralogy research on the raw material and exploratory tests such as flotation, direct cyanide leaching, roasting-cyanide leaching, and biological pre-oxidation-cyanide leaching in the laboratory. The test results show that the separation of sulfur and arsenic in the mine cannot be realized by using arsenic-suppressing and sulfur-floating technology. The reason is that the particle size of arsenopyrite is too fine, and arsenopyrite and pyrite are associated and symbiotic. When pyrite is floated, the association of arsenopyrite and pyrite is floated into the concentrate. On the research basis, the research institute proposed a combined beneficiation-metallurgy process scheme ‘preoxidation-ore desliming-sulfur arsenic coflotation-sulphurization-arsenic flotation-boiling roasting-cyanidation leaching’. The key technologies that the scheme can implement are sulfur-sulphurization-arsenic flotation technology and raw ore desliming technology. At present, the experiment of sulfur suppression and arsenic flotation has been successfully reported. The methods of ore desliming include cyclone desliming and flotation desliming. In the future, the implementation of this combined beneficiation and smelting process will greatly reduce the comprehensive beneficiation and smelting cost of such refractory gold ores.