碳质金矿中金的化学物相分析方法改进

为了解决碳质金矿金化学物相分析结果与选矿试验结果不符的问题,基于岩矿鉴定和测试结果对分析流程进行改进。方法改进后测试项目包括裸露金和半裸露金、有机碳石墨包裹金、碳酸盐包裹金、褐铁矿包裹金、黄铁矿包裹金、石英和硅酸盐包裹金6项。有机碳石墨包裹金选用Na_2S_2O_3–CuCl_2–NH_4OH–NH_4Cl体系为浸金剂,取代I_2–NH_4I体系,该体系中金的测定采用铜置换原子吸收法。裸露金半裸露金、有机碳石墨包裹金和黄铁矿包裹金的相和为82.34%,与选矿试验金精矿实际回收率(75.83%)基本吻合。改进后的方法适合碳质金矿金化学物相分析。

Improvement on Measurement of Chemical Phase Analysis of Gold in Carbonaceous Gold Ores

In order to solve the problem of value deviation between mineral process test and chemical phase analysis of gold in carbonaceous gold ores by traditional procedure,an improved procedure on the basis of the results of rock ore appraisal and testing was proposed. It included the determination of the phases of exposed and half-exposed native gold, gold wrapped by organics and graphite, carbonate meterials,limonite,pyrite,quartz and silicate meterials. The system of Na2S2O3-CuCl2-NH4OH-NH4Cl was used as leaching agents of gold instead of I2-NH4I. Gold in the system was determined by copper replacement-atomic absorption spectrometry. The sum of the phases of exposed and half-exposed native gold, gold wrapped by organics and graphite,and pyrite was 82.34%,which was basically consistent with the recovery rate of gold concentration (75.83%). The improved method is suitable for chemical phase analysis of gold in carbonaceous gold ores.