高砷高碳氧化金矿石提金试验研究

甘肃某金矿矿石中金矿物嵌布粒度微细,属于典型的高砷高碳难处理类卡林型金矿。对该矿石采用单一浮选工艺进行处理时,金回收率仅为21.37%;直接全泥氰化时,金浸出率仅为34.62%。根据矿石的性质及探索试验结果分析,确定采用浮选碳金精矿—碱浸预处理—氰化炭浸工艺进行处理。通过优先浮选可浮性较好的碳,消除碳对氰化浸出"劫金"的影响;利用高浓度氢氧化钠对砷黄铁矿及硫化矿进行化学分解,打开包裹金;再利用氰化炭浸工艺浸出回收金。该工艺在1 000 t/d炭浸厂应用时,可以获得金品位130.21 g/t、回收率12.18%的碳金精矿,尾矿氰化炭浸金作业浸出率72.16%,原矿金综合回收率达到74.34%;这对中国西部类卡林型金矿的生产应用具有借鉴意义。

Experimental research on gold recovery from oxidized gold ores with high content of carbon and arsenic

The dissemination particle size of gold mineral from one gold mine in Gansu province is fine,indicating the deposit is a typical Carlin-like gold deposit with high arsenic and carbon and the ores are difficult to process. The recovery of gold is only 21 . 37 % in the process of single flotation and the all-sliming cyanide leaching rate is only 34. 62 %. According to the features of the minerals and preliminary test results,a flotation-alkaline leaching pretreat-ment-cyanidation CIL process is adopted. The gold-robbing effect is eliminated by preferentially float the carbon with good floatability. Chemical decomposition of arsenopyrite and sulphide ore is realized by taken advantage of high con-centration NaOH,unwrapping the encased gold particle,and then the technology of all-sliming CIL cyanide leaching is applied to recover the gold. During the application of the process in a 1 000 t/d CIL processing plant,a gold grade of 130. 21 g/t and a recovery rate of 12. 18 % are obtained,the tailings' leaching rate of cyanide carbon leaching is 72. 16 % and the comprehensive recovery rate of gold from raw ores is 74. 34 % which is a fairly good index. There-fore this technology process can be referred to for the production application of Carlin-like gold deposit in western Chi-na.