甘肃某卡林型金矿选矿试验研究

Experimental Study on Beneficiation of a Carlin-type Gold Ore in Gansu Province

甘肃某卡林型金矿石金品位为4.04 g/t,载体矿物主要为黄铁矿和毒砂,两者嵌镶密切,黄铁矿普遍含砷,砷的含量为0.69%;同时矿石中金嵌布粒度微细,主要以不可见次显微金为主,因此,矿石中金回收率较难提高。针对该问题,对矿石中载金矿物的赋存状态进行了研究,最终确定采用粗磨强化浮选—再磨再选工艺流程对金进行了回收,与原矿磨矿直接浮选流程相比,金回收率提高了6.75个百分点,金总回收率达到了91.91%。在小型试验基础上开展了扩大连选试验,选别指标与小试接近,连续稳定运转9个班的试验数据表明,采用粗磨强化浮选—再磨再选工艺可获得金品位32.72 g/t,金回收率为91.79%的金精矿,尾矿中金品位降至0.40 g/t。

The gold grade of a carlin-type gold ore in Gansu was 4.04 g/t.The carrier minerals were mainly pyrite and arsenopyrite, which were closely embedded.The pyrite generally contains arsenic, and the arsenic content was 0.69%.At the same time, the gold disseminated in the ore was fine, mainly invisible sub-microscopic gold, so it was difficult to improve the recovery of gold in the ore.In view of this problem, the occurrence state of gold bearing minerals in the ore was studied, and the gold recovery was finally determined by the process of primary grinding-enhanced flotation-regrinding and re-election.Compared with the direct flotation process of raw ore grinding, the gold recovery was increased by 6.75 percentage points, and the total gold recovery reached 91.91%.Based on the small scale test, pilot test was carried out, and the separation indexes were close to that of small scale tests.The test data of 9 consecutive and stable operation showed that gold concentrate with gold grade of 32.72 g/t and gold recovery of 91.79% can be obtained by using primary grinding-enhanced flotation-regrinding and re-election.process, and the gold grade in tailings is reduced to 0.40 g/t.