卡林型金精矿加压氧化—铁矾分解—非氰提金研究

Research on pressure oxidation-iron alum decomposition-non-cyanide gold extraction of Carlin-type gold concentrate

某卡林型金精矿为典型难处理金精矿,绝大部分金被黄铁矿和砷黄铁矿包裹,直接浸出时金浸出率仅为7.8%。针对卡林型金精矿提金困难、氰化提金污染严重等问题,创新性提出了加压氧化—铁矾分解—非氰提金方法。卡林型金精矿经加压氧化预处理和铁矾分解处理可实现包裹金的高效解离,氧压渣和破矾渣在反应时间2 h、活性炭用量50 g/L、搅拌速度400 r/min、温度30℃、pH值1.3~1.5、空气流量2 L/min、液固比4∶1、硫脲用量4 g/L条件下,金浸出率分别为76.2%和86.1%,实现了卡林型金精矿的高效、清洁提取。

A Carlin-type gold concentrate is a typical refractory gold concentrate,and most of the gold is encapsulated in pyrite and arsenopyrite,with a gold leaching rate of only 7.8%by direct leaching.In order to address the difficult gold extraction and severe pollution caused by cyanide leaching in Carlin-type gold concentrate,a gold extraction method using pressure oxidation-iron alum decomposition-non-cyanide gold extraction was proposed.The encapsulated gold can be effectively dissociated after pre-treatment by pressure oxidation and iron alum decomposition.The gold leaching rates of oxygen pressure residue and alum destruction slag were 76.2% and 86.1%,respectively,under the following conditions:reaction time of 2 h,activated carbon dosage of 50 g/L,stirring speed of 400 r/min,temperature of 30℃,pH value of 1.3-1.5,air flow rate of 2 L/min,liquid-solid ratio of 4∶1,and thiourea dosage of 4 g/L.This method realizes efficient and clean extraction of Carlin-type refractory gold concentrate.