关键词: 含砷金精矿, 生物预氧化, 氰化浸金, 反应动力学

Abstract: In order to realize the efficient recovery of gold resources in arsenic-containing gold con⁃ centrate，aiming at the problem that gold minerals in arsenic-containing gold concentrate are wrapped and the efficiency of direct cyanide leaching of gold is low，the process optimization and leaching kinetics char⁃ acteristics of biological pre-oxidation treatment-cyanide leaching of gold are studied.By adjusting the key parameters of pre-oxidation such as grinding fineness，pulp concentration，dissolved oxygen and medium dosage，the encapsulation barrier of arsenic and sulfur minerals to gold particles is broken. The effects of calcium oxide and sodium cyanide dosage，pulp concentration and leaching time on gold leaching are sys⁃ tematically investigated. The strengthening mechanism of gold extraction is revealed by scanning electron microscopy and kinetic fitting analysis.The results show that under the optimal biological pre-oxidation con⁃ ditions，the oxidation rates of arsenic and sulfur in gold concentrate can reach 82.95% and 81.34% respec⁃ tively. Under the appropriate leaching parameters，the average gold leaching rate of the corresponding pre�oxidized slag can reach 92.03%，which is greatly improved compared with the raw oredirect leaching gold leaching rate of 32.45%. Scanning micro-morphology analysis confirms that biological pre-oxidation can generate a large number of pores and cracks on the mineral surface，effectively improving the gold leaching reaction conditions.The results of kinetic fitting show that the leaching process of gold concentrate is con⁃ trolled by both chemical reaction and internal diffusion，which accords with the characteristics of mixed con⁃ trol model. The research results can provide technical support for the efficient development and utilization of arsenic-containing refractory gold concentrate.

Key words: arsenic-containing gold concentrate, biological pre-oxidation, cyanide leaching of gold