Experimental Study Of High Grade Gold Henan Huatai Non-cyanide Treatment Beneficiation

Being a kind of precious metal, gold is widely used in many industry due to its fine physical perforouance and stable chemical properties. Along with the exploiting of resources, high-grade gold ores increasingly rare, the emphasis and difficulty of the ore are how to obtain a relatively high gold recovery.This paper presented a detailed study on process mineralogy of a high-grade gold ores, based on its chemical analysis, the ore assays16.44g/t Au in a complex occurrence state, dominating by electrum in the form of natural element, which accounting for77,25%of total. Secondly exists in pyrite, galena and other sulfide minerals in the form of isomorphism, accounting for16.77%. Thirdly exists in quartz, mica and other gangue minerals in the form of fine-grained dissemination, accounting for5.98%. On the other hand, the associated silver assaying65.5g/t, dominating by pyrite and galena in the form of isomorphism and independent minerals, which accounts for57.8%. Secondly the silver exists in electrum in the form of natural element, which accounts for14.73%. Thirdly the silver exists in quartz, mica and other gangue minerals in the form of fine-grained dissemination, which accounts for0.95%.Extracting gold by cyanide has gradually been prohibited due to the environmental pollution of process, hence non-cyanide process should be considered. In view of the properties and characteristics, initially a contrast test about the sequence of flotation and gravity concentration was conducted and results showed that the combined flowsheet of gravity concentration-flotation was superior to the reverse one, But a limitation for this process is that the tailings after the beneficiation still had a high gold content. Therefore, complementary experimental researches, flotation after regrinding and gravity concentration after regrinding for the above tailings were conducted, which showed that the gold in tailing was locked in gangue minerals and could be recycled by gravity concentration after a fine regrinding, so the combined flowsheet of gravity concentration-flotation-gravity concentration was determined. After the beneficiation conducted by above tests, gold in tailing was reduced to0.86g/t, a gold concentrate with a grade of43.04g/t at the recovery of96.71%, silver gold concentrate with grade of172.49g/t at the recovery of97.28%.