四川某高碱性含铜金矿综合回收钙镁铜金试验研究

Study on Comprehensive Recovery of Calcium,Magnesium,Copper and Gold from High-alkaline Copper-bearing Gold Ore in Sichuan Province

针对碳酸盐、砷和铜含量高的“三高”金矿选矿回收难度较大的问题,采用原矿焙烧脱碳除砷-NH4Cl“闪速”浸钙-(NH4)2SO4浸镁铜-非氰浸剂药剂(swust-1)浸金工艺流程综合回收矿石中有价元素。研究结果表明:当焙烧温度为950℃、焙烧时间为2h、矿浆浓度为30%、-0.074mm粒级含量为70%、NH4Cl浓度为3.0mol/L和浸出时间为10min时,矿石中Ca^2+、Mg2+和Cu^2+浸出率分别为82.88%、20.12%和16.75%;在(NH4)2SO4浓度为2.5mol/L、矿浆浓度为30%和浸出温度为50℃的条件下,经过“两段”浸出,Mg^2+和Cu^2+浸出效果较好。经过“焙烧-浸钙镁铜”后,金的浸出率也大大提高。通过上述工艺流程处理后,钙、镁、铜和金的总浸出率分别可达96.18%、95.16%、80.51%和78.86%,提高了高碱性含铜金矿中有价元素浸出率和综合经济价值。

The high alkaline copper-bearing gold ore usually have the following three characteristics:(1)The alkaline gangue has a high content,and often contains a large amount of carbonate minerals,such as calcite and dolomite.(2)The copper content is relatively high,and the copper content in the ore is usually above 1.0%.(3)The high alkaline copper-bearing gold ore is often mixed with both sulfide and oxidized minerals,as well as arsenic and other toxic and harmful elements. It is difficult to obtain the ideal separation index by conventional mineral processing methods. However,with the gradual decreasement of easily-recover gold ores,more and more attention has been paid to the study on the metallurgical technology of refractory gold ores.The technological process, Roasting of raw ore to remove carbon and arsenic-Rapid leached by ammonium chloride of calcium-Ammonium sulfate leaching of magnesium and copper-Non-cyanide leaching(swust-1)of gold,was used to recover valuable elements from ore,and to increase recovery rate of“three high”gold mine,the gold ores characterize high- carbonate,high-arsenic and high-copper.The result shows that leaching rate of calcium,magnesium and copper reached 82.88%,20.12% and 16.75%,recpectively,when calcination temperature is 950 ℃,calcination time is 2 h, pulp density is 30%,-0.074 mm grain size content is 70%,ammonium chloride concentration is 3.0 mol/L,and leaching time is 10 min. After“two-stage”leaching,the leaching rate of magnesium and copper ion is more higher than unroasted ore,under the condition of ammonium sulfate concentration of 2.5 mol/L,pulp concentration of 30%,and leaching temperature of 50 ℃. After“roasting-leaching of calcium,magnesium and copper”,the leaching rate of gold was also greatly improved.Through the above process,the total leaching rates of calcium,magnesium, copper and gold can reach 96.18%,95.16%,80.51% and 78.86%,respectively,which improve the leaching rate and comprehensive economic value of valuable elements in high-alkaline copper-bearing gold deposits,and has the potential of popularization and application.