A process of biooxidation followed by thiosulfate leaching of gold from refractorygold concentrate was *** studies on the concentrate showed that very fine gold grains(<10μm)were encapsulated in pyrite and arsenopyr...
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A process of biooxidation followed by thiosulfate leaching of gold from refractory gold concentrate was *** studies on the concentrate showed that very fine gold grains(gold was only 21%.The gold-bearing sample was identified as a high-sulfur fine-sized wrapped-type refractory gold *** gold leaching efficiency obtained by direct cyanidation was only 59.86%.After biooxidation pretreatment,the sulfide minerals were almost completely decomposed,92 wt%of the mineral particles of the biooxidation residue were decreased togold in the biooxidation residue was over 86%.Meanwhile,the gold content in the biooxidation residue was enriched to 55.60 g/t,and the S,Fe,and As contents were reduced to approximately 19.8 wt%,6.97 wt%,and 0.13 wt%,*** thiosulfate was used for gold extraction from the biooxidation residue of the refractory gold *** results showed that the optimal reagent conditions were 0.18 M thiosulfate,0.02 M copper(II),1.0 M ammonia,and 0.24 M *** these conditions,a maximum gold leaching efficiency of 85.05%was obtained.
Acid producing bacterium Acetobacter aceti causes pitting corrosion of stainless steel(SS).This work investigated the enhanced resistance of 2205-Cu duplex stainless steel(DSS)against biocorrosion by *** in comparison...
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Acid producing bacterium Acetobacter aceti causes pitting corrosion of stainless steel(SS).This work investigated the enhanced resistance of 2205-Cu duplex stainless steel(DSS)against biocorrosion by *** in comparison with 2205 DSS using electrochemical and surface analysis *** the addition of Cu to 2205 DSS,biofilms on the 2205-Cu DSS surface were inhibited *** largest pit depth on 2205-Cu DSS surface in the presence of A aceti was 2.6μm,smaller than 5.5μm for 2205 DSS *** i(corr)was 0.42±0.03μA cm^-2 for 2205-Cu DSS in the biotic medium,which was much lower than that for 2205 DSS(3.69±0.65μA cm^-2).All the results indicated that the A aceti biofilm was considerably inhibited by the release of Cu^2+ions from the 2205-Cu DSS matrix,resulting in the mitigation of biocorrosion by A aceti.
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