应用尼尔森重选优化河南某氧化型金矿选别指标

Improving the Ore Dressing Indicators of an Oxidized Gold Ore in Henan Province by Knelson Concentrator

河南某金矿矿石中金的品位为2.14 g/t,金主要以裸露及半裸露金的形式存在,占总金的41.20%,其次为硫化物包裹金,占总金的27.31%,硫铁矿包裹金含量较少,为12.04%。目前,选矿工艺为单一浮选流程,金的回收率指标一直不太理想,造成了资源的严重浪费。为降低尾矿金品位,提高金回收率,开展了应用尼尔森重选优化选别指标的试验研究。研究结果表明:①生产尾矿中存在一定量的麦粒状、长角粒状和板片状颗粒金,应用尼尔森重选回收,可获得35.33%的作业回收率;②应用尼尔森从旋流器给矿中回收颗粒金,可以获得金品位为734.40g/t、金回收率为41.07%的重选金精矿;③旋流器给矿与沉砂的重选可回收金(GRG)值基本一致,说明绝大多数GRG颗粒金通过旋流器沉砂进入磨矿循环系统,将尼尔森配置在旋流器给矿处较为合适,进而实现能早收就早收的选矿原则;④采用重浮联合工艺,精矿金的回收率由85.74%提高至90.80%,尾矿金品位由0.35 g/t降低至0.23 g/t。本研究为下一步工业实践提供了借鉴。

A gold mine in Henan province was with the gold grade of 2.14 g/t.The gold mainly existed in the form of exposed and semi-exposed gold accounting for 41.20%of the total gold,followed by gold wrapped in sulfide accounting for27.31%of the total gold.Gold wrapped in pyrite is less which accounted for 12.04%of the total gold.At present,the beneficiation process is single flotation,and the ore dressing indexes are relatively low,which makes the resource terrible waste.In order to improve the grade and recovery rate of the gold,the mineral processing experiments were carried out by Knelson concentrator to reduce gold grade of the tailings.The results indicated that:①Particle gold existed in the production tailings in the form of wheat grain,longhorn grain and plate-flake,which could be recycled with the operating recovery rate of35.33%by using Knelson concentrator.②The gravity concentrate with gold grade of 734.40 g/t and recovery rate of 41.07%could be obtained from the feeding of hydrocyclone by using Knelson concentrator.③The GRG value in the underflow and feeding were basically the same,which means the most gold particles entering the grinding system with hydrocyclone underflow.The beneficiation princple of recycling early as much as possible could be fully embodied by configurating the Knelson concentrator at the feeding of hydrocyclone.④The gold recovery rate of concentrate increased from 85.74%to 90.80%,and the gold recovery rate of tailings decreased from 0.35 g/t to 0.23 g/t by flotation combined gravity dressing technology.The research results would provide reference for the next industry practice.