刚果(金)某高碳酸盐氧化铜矿酸浸前浮选抛尾试验研究

为解决刚果(金)某高碳酸盐氧化铜矿原矿浸出酸耗高、浮选工业指标较差的问题,根据碳酸盐脉石与氧化铜矿物浮选性能差异,采用开路硫化浮选的方法对氧化铜矿物进行选择性富集和对耗酸碳酸盐脉石进行预先抛尾,再使用搅拌酸浸处理浮选粗精矿。结果表明,使用NaHS(1 050 g/t)对矿浆进行硫化,以戊黄药、Z-200和羟肟酸钠按4∶1∶1配合后的组合捕收剂(650 g/t)进行4次开路浮选,得到了铜品位8.16%的粗精矿,回收率达到了94.75%,而耗酸脉石的抛除率则超过80%。对粗精矿在常温常压下进行搅拌浸出,控制浸出过程pH=1.5,搅拌强度200 r/min,浸出2 h,浸出率可达89.75%。采用开路浮选-搅拌浸出联合工艺处理该矿石,在保证总回收率85.04%的情况下,浸出酸耗比原矿酸浸降低80%,搅拌浸出处理量仅为原矿浸出的20%左右,取得了良好的技术经济指标。

Experimental Study on Discarding Flotation Tailings before Acid Leaching for High Carbonatite Copper Oxide Ore from DRC Congo

To resolve problems, such as high acid consumption and poor flotation performance in processing a high carbonatite copper oxide ore from DRC Congo, an open-circuit of sulfidation-floatation was chosen to selectively enrich the copper oxide minerals and discard the acid-consuming carbonatite gangue according to their difference in floatability, with the obtained rough concentrate treated by agitation leaching. It is shown after NaHS (1 050 g/t) was used to sulfurize the pulp, amyl-xanthate, Z-200 and sodium benzohydroxamic mixed at a proportion of 4∶1∶1 was taken as the collector (650 g/t) in the floatation of copper oxide with a four-stage open-circuit flowsheet, a rough copper concentrate grading 8.16% Cu at 94.75% recovery was produced, with 80% of carbonatite discarded as tailings. An agitation leaching of the rough concentrate under normal pressure and at room temperature, with pH value controlled at 1.5 and agitation intensity of 200 r/min, led to the leaching rate at 89.75% after 2-hour leaching. An open circuit with a combined process of floatation-agitation leaching was adopted to process such ore, under the premise of ensuring the total recovery at 85.04%, bringing the acid consumption down by 80% and the volume for agitation leaching down to around 20% of that for raw ore leaching, leading to good technological and economic indicators.