A new process for the hydrometallurgy of refractory gold concentrates was presented. The process comprises grinding leaching, intensified alkaline leaching (IAL), cyanidation and adsorption. In a stirring type pulveri...A new process for the hydrometallurgy of refractory gold concentrates was presented. The process comprises grinding leaching, intensified alkaline leaching (IAL), cyanidation and adsorption. In a stirring type pulverizing leaching tower mill, the concentrate is ground to <35.6 μm of 95.5 % while simultaneously leached by NaOH of 12 kg/t, then carried out intensified alkaline leaching for 48 h by NaOH of 108 kg/t in enhanced agitation tanks with the pulp concentration of 40% solids at the environmental temperature of 9.5 ～ 13.5 ℃ and the environmental pressure of 10 5 Pa. The oxidation rate of As is 94.9%, and 47.6% for S. The total consumption of NaOH is only 20% of that theoretically calculated under the conditions of full oxidation at the same oxidation rates of arsenic to arsenate and sulfur to sulfate. The gold leaching rate by NaCN in 24 h is increased from 9.2% before pretreatment to 94.2%. The consumption of NaCN is 7.5 kg/t, which is one times less than that before pretreatment. The extraction cost of gold is about 422 Yuan/t.展开更多
文摘A new process for the hydrometallurgy of refractory gold concentrates was presented. The process comprises grinding leaching, intensified alkaline leaching (IAL), cyanidation and adsorption. In a stirring type pulverizing leaching tower mill, the concentrate is ground to <35.6 μm of 95.5 % while simultaneously leached by NaOH of 12 kg/t, then carried out intensified alkaline leaching for 48 h by NaOH of 108 kg/t in enhanced agitation tanks with the pulp concentration of 40% solids at the environmental temperature of 9.5 ～ 13.5 ℃ and the environmental pressure of 10 5 Pa. The oxidation rate of As is 94.9%, and 47.6% for S. The total consumption of NaOH is only 20% of that theoretically calculated under the conditions of full oxidation at the same oxidation rates of arsenic to arsenate and sulfur to sulfate. The gold leaching rate by NaCN in 24 h is increased from 9.2% before pretreatment to 94.2%. The consumption of NaCN is 7.5 kg/t, which is one times less than that before pretreatment. The extraction cost of gold is about 422 Yuan/t.
