Experimental On Gold Extraction Process Of A Gold Mine In Indonesia

A gold mine has abundant reserves of gold mine with high gold grade in Indonesia,which has great development and utilization value.Study on detailed ore process mineralogy was carried out on the gold ore,and all-slime cyanidation,single flotation test,flotation tailings cyanide leaching test,and flotation gold concentrate cyanide leaching test were carried out to determine a best beneficiation solution and conditions.The gold ore contains Au 8.76 g/t,and the gold minerals are mainly silver-gold and natural gold.The main metal sulfides are mainly pyrite,followed by Arsenopyrite,chalcopyrite,sphalerite,and galena.The gangue mineral is mainly composed of quartz,followed by feldspar,kaolin,biotite,sericite,chlorite etc.The results of cyanide leaching test showed that the leaching rate of gold reached 79.38% in the condition of grinding fineness of-0.074 mm 95%,consumption 15 kg/t of CaO,consumption 6 kg/t of NaCN and leaching time in 24 h.We can get gold concentrate with grade of 63.79 g/t and a recovery rate of 64.30% by closed-circuit flotation of 1-time roughing,2-time concentrate,3-time scanvenging,with a grinding fineness of-0.074 mm of 65%.The recovery rate of a single flotation process gold is low,and gold cannot be recovered efficiently.Conducting cyanide leaching for flotation roughing tailings,it shows that leaching rate reached 90.98%,under the condition of grinding fineness is-0.074 mm 95%,the CaO dosage is 10 kg/t,the NaCN dosage is 5 kg/t,and the leaching time is 48 h.The total recovery of gold in the flotation-tailing cyanide leaching process reached 96.16%.The flotation gold concentrate is subjected to a roasting-cyanide process and pretreated by oxidation roasting,and the gold leaching rate reaches about 88%.According to the status of the development and utilization of the gold mine,we prefer to use flotation-tailings cyanidation processing flow and selling the gold concentrate.The gold mine is planned to build a 150,000 t/a processing plant with a total investment of RMB 120,747,200 an annual net profit of RMB 127,977,100,and a posttax investment recovery period(including the infrastructure period)of 1.9 years.Figure36;Table23;Reference 65.