含硫砷含碳金精矿提金工艺研究

针对含硫砷含碳金精矿的性质,进行了提金工艺探索。该金精矿经直接氰化浸出,金浸出率仅为1.33%;经两段焙烧—氰化浸出,金浸出率提高到71.33%,但该方法所需时间长、能耗高、有害元素的脱除不完全且容易发生过焙烧。鉴于此,提出了一段富氧添加硫酸钠焙烧—硫化钠碱浸强化—焙砂氰化浸出提金工艺。一段富氧添加硫酸钠焙烧不但可强化硫、砷和碳的脱除,降低焙烧温度50℃,缩短焙烧时间至30 min以内,而且少量硫酸钠的添加可消除焙砂的固结问题,使金的浸出率增加到84.14%;而对焙砂再进行硫化钠碱浸处理,不仅使被包裹的金得到进一步解离,金浸出率提高到94.72%,且可以回收锑,实现金矿资源的综合回收利用。

Study on gold extraction from carbonaceous gold concentrates containing sulfur and arsenic

According to the property of carbonaceous gold concentrates containing sulfur and arsenic,the paper carried out experimental research on gold extraction. Gold extraction only reaches 1. 33 % by direct cyanidation leac-hing. Gold recovery increases to 71. 33 % by two-stage roasting pretreatment,but the method has the disadvantages of long processing time,high energy consumption,incomplete removal of detrimental elements and incidental over-roast-ing. In light of that,the paper proposed that the ores be treated by one-stage oxygen-rich roasting with sodium sulfate additive and the calcine be leached by cyanidation after intensified by alkaline leaching by sodium sulfide. One-stage oxygen-rich roasting with addition of sodium sulfate not only intensifies the removal of sulfur,arsenic and carbon,cools the roasting temperature by 50 ℃,shortens time to less than 30 minutes,but solves the consolidation problem of cal-cines by adding a small amount of sodium sulfate,eventually increasing Au extraction to 84. 14 %. After the calcine was subjected to alkaline leaching by sodium sulfide,the encapsulated gold got effectively liberated and the Au recov-ery was elevated to 94. 72 %. Also,antimony could be recovered and comprehensive recovery of gold ore resource was realized.