Experimental Study on Gold Recovery from a High-Sulfur Gold Tailings by Beneficiation-Metallurgy Combination
Online published: 2024-07-03
In order to realize the high-efficiency recovery of gold from gold tailings,an experimental study was carried out on gold tailings in Shaanxi Province.The chemical analysis shows that 11.60% S,1.5 g/t Au and 84.77% wrapped gold is contained in the raw material,which belongs to high-sulfur wrapped refractory gold ore.Due to the difficulty to separate gold from sulfur by a single flotation process,and obtaining qualified concentrate products,the combined process of pretreatment-flotation preconcentration-flotation middling regrinding-leaching was applied in the experimental research to improve the gold recovery.The results show that with mechanical agitation,ultrasonic,and pretreatment with H2SO4 and Na2S,the surface properties of gold minerals can be improved and the flotation recovery increase,among which H2SO4 is the best pretreatment.With 100×10-6 of sulfuric acid,110×10-6 of copper sulfate,80×10-6 of butane yellow,40×10-6 of butane black and 30×10-6 of 2 # oil,and after two roughing operations,the mixed coarse concentrate product with an gold grade of 6.94×10-6 and a recovery rate of 87.22% are obtained.The flotation recovery rate is 10.52% higher than that without pretreatment,realizing the preconcentration of bare gold and sulfide-coated gold.As the gold in the coarse concentrate is mostly in sulfide wrapped state,it is difficult to achieve full productization.Therefore,under the conditions that the amount of sodium silicate,sodium hexametaphosphate,and NaCN is 500×10-6,200×10-6,and 50×10-6 respectively,the sulfur suppression concentration process is adopted to obtain a gold concentrate with an gold grade of 21.65×10-6 and a part of qualified gold concentrate products are obtained.The beneficiated middlings was leached for 48 h under the conditions of -400 mesh gold concentrate,accounting for 95%,and NaCN concentration of 0.16%,the direct leaching rate is 91.48%,and the final combined recovery rate of gold is 80.45%,showing the realization of the efficient recovery of gold from the high sulfur wrapped refractory gold tailings resources.
Wei YANG, Jinqiu YE, Tao LONG, Sha DENG, Wentao WANG . Experimental Study on Gold Recovery from a High-Sulfur Gold Tailings by Beneficiation-Metallurgy Combination[J]. Gold Science and Technology, 2023 , 31(1) : 113 -122 . DOI: 10.11872/j.issn.1005-2518.2023.01.154
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