recovery of g from sulfide refractory g oreapr 01, · the method consisted of two stages roasting for arsenic and sulfur removal, g recovery by thiourea leaching, followed by an enhanced chlorination roasting for g recovery in the presence of pyrite. in the twostage roasting process, the phase transition of feass and fes 2 during the roasting process was analyzed.author hong qin, xueyi guo, qinghua tian, dawei yu, lei zhangmicrobial oxidation of g ores and g bioleachingjun 01, 94· abstract. much recent work in the field of biohydrometallurgy has been directed to the study of biooxidation of g ores by acidophilic iron and sulfur oxidizing microorganisms. this work has been done worldwide and has resulted in several pilot plant and commercial scale operations for g ore biooxidation.biological oxidation of sulphide minerals to recover gthis invention relates to the oxidation of sulphide minerals, including the recovery of g from sulphide minerals, by means of biological oxidation. biological oxidation of sulphide ores, especially pyritic g ores, has been known for some time and there are many references in the literature to ore processing in this way.efficient strategies to enhance g leaching duringjul 30, · the high reactivity of sulfide minerals in alkaline cyanide solutions makes g cyanidation a multifactorial process controlled by the mineralogy of the host rock and where g recovery is a complex outcome from g surface passivation, galvanic interactions between the conducting phases (i.e., ausulfide and sulfidesulfide) present in multisulfidic ores and excessbacterial oxidation of refractory sulfide ores for gsep 27, 08· the overall oxidation of the sulfides is an important variable for g recovery. pilot and commercialscale bioleaching processes for gcontaining pyrite and arsenopyrite ores are reviewed. this application of mineral biotechnology competes favorably with pressure leaching and roasting processes, both of which are problematic and energyintensive alternatives for pretreatment of auriferous pyrite/arsenopyrite ores.cited by 98potential pretreatment and processing routes for recovery2.1 microwave pre treatment of refractory g ores . most of refractory g occurs within sulphide minerals such as fes 2 and feass and are treated by roasting, pressure leaching or bacterial leaching to render the g amenable to recovery by subsequent treatment techniques (haque, 87).biooxidation of arsenopyritic and pyritic containing gbeing the most common sulfide minerals, arsenopyrite and pyrite under oxidizing conditions breaks down to release acids of as and s into the environment, leading to acid mine drainage with high concentrations of dissolved as. in this research, the dissolution of g ore (with fes2 and feass as the main sulfides) from tianli g mine, liaoning province, china was investigated.
the influence of pyrite preoxidation on g recovery byjul 01, 06· to find maximum g recovery after complete sulfide oxidation, a series of hot nitric acid pretreatment tests were performed on the fineground samples and followed by cyanide/cil. after the nitric acid pretreatment, the sulfide oxidation was over 99.2%.leaching of copper sulphides saimmthe recovery of other valuable metals such as g and silver can be carried out economically. phase are an important parameter in enhancing the rate of the sulphide oxidation reaction. in general, ferric sulphate leaching of secondary sulphide ores has been successfully commercialised at the cobre las cruces (clc) and sepon copperg recovery 101 sepro mineral systemsviable. if the g is encapsulated in sulfides, oxidation of the sulfide minerals by roasting, pressure oxidation or biooxidation can be employed. chemical interference various minerals can interfere with the leaching process by consuming cyanide or dissolved oxygen. inatmospheric alkaline preoxidation of refractory sulphideatmospheric alkaline preoxidation of refractory sulphide g ores. creator. rego, alan joseph. publisher. university of british columbia. date issued. . description. four ironsulphidecontaining g ores from the white mountain mine in the jilin province, china were studied to examine the benefits of using oxidative treatment prior tov1n8a4 evaluation of ozonation technology for gstages of g processing in order to improve g recovery, reduce operating costs by recycling cyanide, and minimize the environmental impact by efficient detoxification of the effluent streams. 8% 72*0 refractory g, g recovery, preoxidation, ozonation, cyanide detoxification. * mintek, randburg, south africa.technical session 2b preoxidation of refractory ores 1sep , · he came back to academia in and his research interests are ore characterization, hydrometallurgical processes of g and copper, rare earth elements, biohydrometallurgy of refractory sulfide ores and novel sulfide oxidation processes, recycling metals from urban resources, mine water treatment, repurposing mine tailing, and biological derecovery of g in pyritic sulfide ores mine engineerusing cyanide to recover g from sulfide ores generally results in 30 to 35% recovery, and the best i have heard of is around 50% recovery. the fine coating of a iron compound definitely appears to be a key component of the inability of cyanide to efficiently leach low grade pyritic ores. perhaps there is some room here for a pretreatment, toprocess mineralogy as a tool for improvingrecovery of complex sulphide ores an overview by p. a. olubambi and j. h. potgieter of chemical and metallurgical engineering, university of the witwatersrand, johannesburg, south africa abstract process mineralogy is one of the most important and fundamental tools for obtaining optimum economic recovery, but is often overlooked.wo6350a1 method for recovering g from sulfidethis method for recovering g from sulfide ore comprises a first step in which sulfide ore or leach reside remaining after sulfide ore has been subjected to leaching is brought into contact with...author , ,
pressure oxidation of a refractory sulfide concentrate andaug , · pressure oxidation of the refractory sulfide/carbonaceous ores has gained worldwide acceptance. compared with roasting, pressure oxidation yields higher g extractions from ores or concentrates and enables better handling of environmentally sensitive impurities. normally, g is extracted from neutralized autoclave leach residue by cyanidation.estimated reading time 9 minscn100485059c method for recovering g from sulphidethe invention relates to a method for recovering g from a sulphidic concentrate, particularly one containing arsenopyrite and/or pyrite, hydro metallurgically. the concentrate is first...author j·, o·, s·, v·, m·（）flexicone technology for sulfide ores flexicone100% g recovery from sulphide concentrates the possibility of using only gravity recovery after oxidation and complete or partial rejection of the leaching process. grinding and oxidation of sulfides is carried out in a vortex ultrasonic reactor.review pretreatment process on refractory g ores with ascial plant which applied bacterial oxidation to pretreat refractory g ores was built in south africa. after bacterial oxidation, sulphide decomposition, arsenic comes into the solution, so as to remove arsenic. the process is showed in fig. 4. the reactions are as follows 39 4 23 2 33 3 43 feass naoh o na ass na aso fe oh ++ =+ + 44 36high pressure oxidation gmay 27, · g recovery from refractory g concentrates by . 31 · keywords g pressure oxidation thiosulfate leaching rsm 1. introduction g was an important rare and precious metal always coexists with sulphide minerals such as pyrite and arsenopyrite (azizi et al. 10 nunan et al. ). due to the depletion of highgrade g ores. chatsulphide g ore treatment by leaching and flotation processapr , · problem with g recovery from sulphide ore how may a mill get the maximum recovery of g from a sulphide ore, at the least capital cost and at the same time obtain the highest net return.this latter point is most important. in many cases a g mill using an allcyanide flowsheet with fine grinding of all the ore will report very low g content in the tailings particularly on anestimated reading time 6 minsbacterial leaching as a pretreatment step for gtime) to achieve acceptable levels of sulphide oxidation and subsequent g recovery. sulphidic material with as little as 0.7 g/t of g content can be profitably bioheap leached with 6070% g recovery. industry estimates place bioheap leaching costs at (46)/t of ore processed (brierley, 95). industrial applications bacterial leaching as a pretreatment step for gfor one concentrate, g recovery of 81% was achieved following an 87% oxidation compared with 24% recovery by direct cyanidation of nonoxidized concentrate.