氯离子对难处理金精矿生物预氧化-炭浸氰化的影响

Effect of Chloride on Bio-oxidation and Carbon-in-leach Cyanidation of Refractory Gold Concentrate

高盐矿区往往缺乏淡水资源供生产使用。针对矿区盐水现状,进行高砷难处理金精矿生物氧化-氰化提金试验,考查不同氯离子浓度对硫化物氧化率、金浸出率等技术指标的影响。结果表明,氯离子浓度对金精矿生物氧化的不利影响随着浓度的升高而增强,氯离子浓度1.5 g L以上时,硫化物的氧化率显著降低,10 g L氯离子盐水生物氧化延长至18 d,砷浸出率88.4%,硫氧化率仅为35.3%。相同生物氧化渣在相同氰化条件下采用清水和10 g L氯离子盐水进行氰化浸出时,盐水将降低金的浸出率。1.5 g L、5 g L氯离子盐水生物氧化10 d后的氧化渣采用10 g L氯离子盐水氰化,金的浸出率分别比清水氰化时的分别低2.8、3.4个百分点。难处理金精矿生物氧化砷浸出率均高于硫氧化率,表明毒砂氧化率高于黄铁矿,金浸出率与毒砂氧化率的相关性较黄铁矿氧化率更加密切。

High salt mining areas often lack fresh water resources for production.In view of the saline status in mining area,the biooxidation-cyanidation gold extraction tests for high arsenic refractory gold concentrate were carried out by using water with different chloride concentration.Effect of chloride in biooxidation solution on sulfide oxidation rises with increase of chloride concentration.At the level of 1.5 g L Cl-or above,the negative impact of chloride is signficant.Biooxidation via salt water with 10 g L Cl-extends to 18 days,arsenic extraction and sulfur oxidation is 35.3%and 88.4%respectively.Water quality used in cyanidation has influence on the cyanidation of biooxidation residue:gold extraion with 10 g L Cl-salt water under the same cyanidation conditions is lower than that with tap water.After biooxidation for 10 days with 1.5 g L and 5 g L Cl-salt water,subsequently gold extraction of caynidatioin with 10 g L Cl-salt water is 2.8%and 3.4%lower than that with tap water.In biooxidation,arsenic extraction is higher than sulfur oxidation,demonstrating that arsenopyrite oxidation is higher than pyrite.Gold extraction is closely correlates to arsenopyrite oxidation.