某高硫含砷碳低品位难处理金矿选矿试验研究

Experimental Study on Beneficiation of Arsenic/carbon-bearing Refractory of Low-grade Gold Ore Containing High Sulfur

某低品位金矿石原矿含金1.68 g/t,砷0.43%、碳0.40%、硫3.20%,金以显微或次显微形式浸染于毒砂、黄铁矿、褐铁矿中,具有载金矿物粒度细、砷和碳含量高等特点,是典型的低品位含砷碳极难处理金矿石,严重影响金的浮选指标。为回收利用矿石中的金,分别进行了直接全泥氰化浸出、重选、浮选三种方案对比试验研究。结果表明,直接全泥氰化浸出率仅5%,重选金精矿回收率不足10%,浮选可获得金品位15.04 g/t、回收率77.13%的金精矿。由于浮选金精矿含砷、碳、硫有害元素均较高,浮选尾矿含金0.42 g/t,损失较高,因此试验采用焙烧预处理以脱除金精矿和尾矿中的有害元素,然后焙砂氰化浸出回收金。最终试验采用浮选—金精矿焙烧氰化浸出—尾矿焙烧氰化浸出联合工艺,得到金总回收率70.66%的较好指标,有效地回收了矿石中的金。

A low-grade gold ore contained Au of 1.68 g/t,As of 0.43%,C of 0.40%and S of 3.20%,respectively,and the gold was disseminated in arsenopyrite,pyrite and limonite in microscopic or submicroscopic form.The ore was a typical refractory ore containing arsenic and carbon with the characteristics of fine particle size,high arsenic and carbon,which seriously effected the recovery of the gold.In order to recover the gold from the ore,cyanide leaching,gravity separation and flotation were carried out respectively.The results showed that the gold cyanide leaching recovery rate was only 5%,and the recovery rate of gravity separation was less than 10%.The gold concentrate could be obtained with Au grade of 15.04 g/t and Au recovery rate of 77.13%by flotation.Because of the higher harmful elements such as arsenic,carbon and sulfur in the gold concentrate and the higher loss of gold(0.42 g/t)in the flotation tailings,roasting pretreatment was adopted to remove harmful elements in gold concentrate and tailings,and then cyanidation leaching of calcine was used to recover gold.Finally,the total gold recovery rate of 70.66%was obtained by using the combined process of flotation,concentrate roasting cyanidation leaching and tailing roasting cyanidation leaching scheme.The gold of the ore was recovered effectively.