Pressure Oxidation Pretreatment of Refractory Gold
Pressure oxidation of gold containing concentrates and ores is an effective pretreatment for liberating refractory gold. This is particularly true when an appreciable portion of the gold is associated with sulfides and is not amenable to conventional cyanidation. A brief review of the literature on pressure oxidation of refractory gold materials is presented. The chemistry of the …
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Extraction of Gold from a Low-Grade Double Refractory Gold Ore …
The treatment process of a low-grade refractory gold ore containing sulfide minerals and carbonaceous matters was studied in this work. The gold extraction of this ore by all-sliming cyanidation was only 11.75%. Hence, a pretreatment was necessary. In this paper, a flotation-preoxidation-cyanide leaching process was developed. The concentrate from the …
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How to Apply Microwave-Assisted Leaching for Faster Gold and …
Microwave-assisted leaching involves the use of microwave radiation to heat the leaching environment, which accelerates the chemical reactions between the reagents and the metal ores.
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Recovery of gold from sulfide refractory gold ore: Oxidation …
The chemicals used in leaching gold ore can harm human health and seriously pollute the environment (Peng et al., 2021). ... ton ore, without NaClO 3, microwave power 700 W and roasting time 30 ...
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Optimization of microwave-assisted roasting: Box-behnken …
Using highly hazardous chemicals impedes leaching and poses a significant risk to human health and the ecosystem [19].In addition, the presence of impurity metals in RGO, such as copper, zinc, and nickel, increases the need for oxidants and cyanide, which forms a coating on the gold surface, impedes the leaching, and reducing the rate of gold recovery [19, 20].
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CN101225467A
The invention relates to a method to pre-treat a hard-to-leach gold ores-pyrite by microwave roasting, which is characterized in that the gold ores-pyrite or fine gold ores-pyrite with the granularity being 200 meshes which takes 90% to 95% of the whole gold ores-pyrite is positioned in a reaction chamber of a microwave roasting oven, a nitrogen is filled fully into the reaction …
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Microwave-assisted Leaching-A Review [J]
This paper reviews microwave-assisted leaching of copper, gold, nickel, cobalt, and manganese, lead and zinc and also coal desulphurisation. ... vat and/or pressure leaching. 17, 18 Several ...
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Oxidation of sulfide mineral and metal extraction analysis in the
Pretreatment using microwave-assisted roasting with NaClO 3 as an additive to the oxidizing agent is a new method of processing refractory gold ore. Oxidation was studied …
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A clean and efficient innovative technology for refractory sulfide gold
In the light of mentioned above, pyrolysis pretreatment of sulfide gold ore can expose the encapsulated gold. Meanwhile, the pyrolysis products of pyrite are self-generating thiosulfate at atmospheric pressure by our proposed scheme, and applying it to the green extraction of gold has become a reality (Ou et al., 2022).Hence, the specific aim of this study is …
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A fundamental study of the alkaline sulfide leaching of gold
gold electrode (m2), and t is the time elapsed (s). Thus, the slope of the kinetic plot is a measure of the leaching rate. It can be seen from Figure 1 that the gold/silver leach rate increases as a function of time, eventually reaching a steady state value after 350s. At steady state, the leaching rate for gold/silver is
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Sulfidic gold ore leaching by cysteine in the presence of Na
Cysteine (CSH: C 3 H 7 NO 2 S) was used to leach gold and silver from sulfidic gold ore with a grade of 29 g/t Au and 28 g/t Ag. <20% of the gold was enclosed in sulfides/silicates, and over 70% of the silver was Ag 2 O. The gold extracted by 0.5 M cysteine at 70 °C was 42% in 24 h. When leaching was conducted at an initial pH of 11.5, the leachate was very alkaline, pH …
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Pretreatment of arsenic-bearing gold ore with microwave …
gold ore through air oxidation and sodium hydroxide leaching under the effect of microwave irradiation was investigated.
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Process for treating refractory gold ores by roasting under …
Therefore, it is crucial to eliminate the preg-robbing phenomenon of carbonaceous matter and oxidized sulfides before the leaching of carbonaceous gold ore. Oxidation roasting, pressure oxidation ...
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Concentrate Using Microwave Assisted Leaching
Microwave-assisted leaching experiments for gold recovery were conducted for the refractory gold concentrate. More extreme reaction conditions (nitric acid concentration 1.0 M) facilitated...
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An application of microwave pre-oxidation in improving gold recovery …
A high carbon low-grade gold ore, in which gold mainly occurs in carbonaceous matters, is a typical refractory gold ore whose conventional cyanide leaching extraction is only 12.9 %.
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Recovery of Gold from the Refractory Gold …
The recovery rate of gold in the leach residue was improved with microwave-assisted leaching, with a gold recovery of ~132.55 g/t after 20 min of the leaching experiment (2.0 M nitric acid), according to fire assays.
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Microwave heating of gold ores for enhanced
In this research, microwave pretreatment was used to augment the grinding of a free-milling gold ore containing quartz, silicates and iron oxides. Under microwave irradiation, …
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Microwave-assisted leaching—a review
Various authors have suggested potential applications of microwave energy in mineral extraction and several review papers can be found in this area Xia and Pickles, 1997, Kingman and Rowson, 1998, Haque, 1999.It was indicated that microwave energy could have a potential application in comminution, drying, pre-treatment of refractory gold ores, coal …
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(PDF) Evaluation of pre-treatment methods for gold …
A new hydrometallurgical process for a carbonaceous refractory gold concentrate at ambient temperature and pressure was presented, including grinding-leaching, intensified alkaline leaching (IAL ...
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Extraction of Gold from a Low-Grade Double Refractory Gold Ore …
The treatment process of a low-grade refractory gold ore containing sulfide minerals and carbonaceous matters was studied in this work. The gold extraction of this ore by all-sliming cyanidation ...
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Review Pretreatment Process on Refractory Gold Ores with …
refractory gold ore.8,9) Haque K E used microwave to dis-pose of arsenical pyrite and gold concentrate with pyrite, the gold leaching rate reached 98%.10) ... and is bad for cyanidation leaching. High temperature and pressure are good for avoiding the generation of sulphur. The process can be carried on not only in acidic medium
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Technology for Aiding the Cyanide Leaching of Gold Ores
Cyanide leaching technology was studied for low-grade oxidized gold ores in Guangxi Province. The gold grade of the raw ores was 1.32 g/t. The gold leaching rate was 90.91% under the optimal conditions for the following conventional leaching process: using steel forging as the grinding medium, a grinding fineness of −0.074 mm accounting for 92.53%, a …
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Microwave Treatment of Minerals and Ores: Heating Behaviors
The application of microwave technology in mineral metallurgy is a transformative approach to ore processing that offers new ideas about the current progressive depletion of resources and the environmental impact of mineral processing. This review delves into the principles, applications, and future directions of microwave treatment in mineral and ore …
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Microwave pretreatment of a double refractory gold ore
Double refractory gold ores, such as Barrick's Goldstrike ore, contain both pyrite and carbonaceous matter and the latter results in the loss of gold from solution during cyanide leaching. ... For both conventional and indirect microwave roasting, gold recoveries of over about 98% were achieved after cyanide leaching. For microwave roasting ...
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COMPARISON OF CYANIDE AND THIOSULPHATE …
Before leaching the gold, ore must be crushed and grinded into small particles, usually particle size varies between 30 and 180 μm. Free milling ores are ready for leaching after crushing and grinding whereas refractory ores need pretreatment. It is important to pretreat a refractory ore before leaching to achieve better gold extraction.
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Oxidation of a refractory gold concentrate using pressure
The gold group at SGS Minerals Metallurgy (Malaga, Western Australia) has conducted a test programme in which a refractory gold ore sample was beneficiated by bench-scale floatation to generate a bulk sulphide concentrate grading 10.6 g/t Au, 13.1% S, 11.4% Fe, 0.18% C and 2.36% As. Mineralogical analyses determined that gold in the ore was ...
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Microwave heating of gold ores for enhanced
Microwave heating of gold ores for enhanced grindability and cyanide amenability ... 1995), (2) the use of high energy to propagate micro-crack formation such as the high pressure grinding rolls (Schonert, 1988) and (3) electrical/ultrasonic energy (Parekh et al., 1984, Walkiewicz et al., 1991). ... Leaching of gold from a free milling gold ore ...
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Leaching of nickel laterite ore assisted by microwave technique
DOI: 10.1016/S1003-6326(10)60016-7 Corpus ID: 55676750; Leaching of nickel laterite ore assisted by microwave technique @article{Zhai2010LeachingON, title={Leaching of nickel laterite ore assisted by microwave technique}, author={Xiujing Zhai and Qiang Wu and Yan Fu and Lin-zhi Ma and Chuan-lin Fan and Nai-jun Li}, journal={Transactions of Nonferrous …
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Microwave pretreatment of a double refractory gold ore
In the study of utilizing microwaves in the pretreatment of carbonaceous sulphidic gold ores, microwave roasting ... temperature at 308.15 K; oxygen pressure at 0.5 Mpa; leaching time of 18 h and ...
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Evaluation of pre-treatment methods for gold recovery from …
quartz and talc. Gold recovery by direct cyanidation was low at 17.3%. Mechanical (ultra fine grinding . P. 80 -16μm) and chemical (alkaline, NaOH) pre-treatment and microwave roasting and microwave-assisted cyanide leaching were investigated to increase gold recoveries. Ultrafine . grinding was the most effective, producing recoveries of 66.5%.
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