提高河南某低品位金矿金回收率试验研究

Experiment on Improving the Gold Recovery Rate of a Low-grade Gold Mine in Henan

河南某低品位金矿具有嵌布粒度不均匀、粒级分布宽和脉石夹杂严重等特点,金矿物的回收困难。为提高金的回收率,在工艺矿物学的研究基础上进行了一系列的选矿试验研究工作。结果表明:①原矿主要有用矿物为自然金,原矿金品位为1.39 g/t;银品位为3.35 g/t,可以作为伴生金属综合利用。次要金属矿物主要为黄铁矿,另含有少量的黄铜矿、磁铁矿、辉铋矿和方铅矿等,脉石矿物主要为石英、斜长石、绿泥石、云母、白云石、方解石,其次含少部分角闪石。②金颗粒主要是以包裹金(占58.83%)形式存在,其次是裂隙金(占23.53%),粒间金占比较小(占17.65%),其中石英包裹金占19.11%。③在最佳的试验条件下,采用重—浮联合工艺,经3次尼尔森重选、1次摇床精选,重选尾矿经"1粗2精2扫"浮选,最终可以获得重砂含金986.60 g/t、金回收率为50.42%及浮选精矿含金35.75 g/t、金回收率为41.57%。全流程金的总回收率达到了91.99%,较好地完成了该矿区金矿物的回收。

A low-grade gold deposit in Henan province are characterized by uneven grain size,wide grain size distribution and serious gangue inclusion,which makes it difficult to recover the gold minerals.In order to improve the recovery rate of the gold,a series of beneficiation experiments were carried out on the basis of mineral processing.The results showed that:①the main useful mineral of the raw ore is native gold.The gold grade is 1.39 g/t in the raw ores.The grade of the siliver is3.35 g/t,which could be recycled as the associated metal.The secondary metal minerals are mainly pyrite,with a small amount of chalcopyrite,magnetite,bismuth an dgalenite.The gangue minerals mainly are quartz,plagioclase,chlorite,mica,dolomite and calcite,followed by a small amount of amphibole.②Gold particles mainly exist in the form of wrapped gold accounting for 58.83%,followed by cracked gold accounting for 23.53% and intergranular gold accounting for 17.65%,in which the gold in quartz accounting for 19.11% of the gold.③Under the best test conditions,the combined process with gravity separation and flotation was adopted.After three times Nelson gravity separation and one cleaning with shaker,the heavy separation tailings were floated by one roughing,two cleaning and two scavenging.Finally,the gravity sand contains 986.60 g/t of gold,the gold recovery rate of 50.42%,and the flotation concentrate contains 35.75 g/t of gold,and the gold recovery rate of 41.57% were obtained.The total recovery rate of the gold in the whole process reached 91.99%,which well completed the recovery of the gold in the mine.