A simplified system boundary is also observed in Fig. 2, showing various stages from comminution to electrowinning for producing 1 kg gold from double refractory ores in a roasting process plant. A roasting facility in Nevada was developed to process 12,000 t of double refractory ore daily (Thomas et al., 1997; Thomas and Cole, 2016).
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The characteristics of gold ores change with time during exploitation from free-milling to refractory and double refractory gold ores. This prevents extraction of the minerals of interest in ...
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The bio-treatment of double refractory gold ores (DRGO) to reduce preg-robbing needs to account for the heterogeneity of the ore so as to acquire a much more complete picture of the system. To ...
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refractory gold ore (double refractory). This was a very disappointing finding. A small scale gravity and flotation test programme was developed to produce a concentrate with the majority of the gold. This also failed with most of the gold remaining in the tailings. An ICP scan also showed variable levels of antimony.
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DOI: 10.1016/j.hydromet.2024.106330 Corpus ID: 269862156; Complete gold extraction and recovery from double refractory gold ores by thiourea after bio-oxidation @article{Sasaki2024CompleteGE, title={Complete gold extraction and recovery from double refractory gold ores by thiourea after bio-oxidation}, author={Keiko Sasaki and …
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This chapter introduces the mineralogical and chemical changes in the various solid residues produced during a sequential biotreatment, consisting of the liberation of gold from sulfides by an iron-oxidizer and decomposition of carbonaceous matter by lignin-degrading enzymes secreted from a white rot-fungus, which successfully …
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Removal of TCM from unoxidized, double refractory ores has been problematic due to significant gold losses in the TCM concentrate, which renders such removal impractical. Removing TCM from oxidized sulfide products can circumvent such gold losses and reduce the preg robbing behavior of the ores.
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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. One possible remedy is to roast the ore and thus oxidize the pyrite and remove the organic carbon. In this research, microwave roasting of a double ...
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La homeopatía es una práctica médica alternativa creada a finales del siglo XVIII por el médico alemán Hahnemann. Surgió como una respuesta crítica a los métodos tradicionales de la época, que Hahnemann consideraba excesivamente invasivos y nocivos; recordemos que la medicina actualmente es considerada un arte y una ciencia …
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AMANKWAH R K, YEN W T, RAMSAY J A. A two-stage bacterial pretreatment process for double refractory gold ores [J]. Minerals Engineering, 2005, 18(1): 103âˆ'108. [8] PYKE B L, JOHNSTON R F, BROOKS P. The characterization and behavior of carbonaceous material in a refractory gold bearing ore [J]. Minerals …
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Environmentally friendly pretreatment of double refractory gold ores (DRGO) to improve gold recovery without emitting pollutant gas is challenging. Sequential biotreatment, including iron-oxidizing microorganisms to decompose sulfides, followed by the enzymatic decomposition of carbonaceous matter, was recently developed. ...
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Sulfides and carbonaceous matter in double refractory gold ore (DRGO) were bio-treated sequentially using an iron-oxidizing archaeon Acidianus brierleyi followed by lignin peroxidase-dominating crude enzymes released from the white-rot fungus Phanerochaete chrysosporium to significantly improve gold recovery from 24% to 92%. …
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Carbonaceous sulfidic gold ores are commonly double refractory and thus require pretreatment before gold extraction. In this paper, the capacity of pre-bio-oxidation can simultaneously decompose sulfides or …
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The initial results for the cyanide leach gold recoveries were very poor on a high grade primary sulphide ore of 6.2 g/t Au with no silver. Subsequent mineralogy showed the ore …
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Removal of TCM from unoxidized, double refractory ores has been problematic due to significant gold losses in the TCM concentrate, which renders such removal impractical. Removing TCM from oxidized sulfide products can circumvent such gold losses and reduce the preg robbing behavior of the ores.
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However, refractory and double refractory ores are not easily treated by cyanidation because gold is locked within the sulfide minerals in refractory ores (Natarajan, 2018; Norgate and Haque, 2012; Vaughan, 2004). Furthermore, double refractory ores indicate preg-robbing properties caused by carbonaceous matter in the …
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Double refractory gold ore (DRGO) not only include ppt levels of gold grains locked in sulfide minerals but also a problematic amount of carbonaceous matter. …
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Double refractory gold ores (DRGO) contain metal sulfides that encapsulate gold and prevent its dissolution by cyanide, and carbonaceous matter (CM) that adsorbs gold cyanide complex. Pretreatment is therefore required to decompose the sulfides and liberate gold before cyanidation, and to deactivate CM and prevent it from adsorbing gold during ...
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Double refractory gold ores (DRGOs), in which few percentages of carbonaceous matter are present and gold grains are encapsulated in sulfides, have been abandoned to develop due to economic loss ...
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Double refractory gold ores (DRGOs), which are carbonaceous refractory gold ores, are a more challenging target than non‑carbonaceous ores (Konadu et al., 2020). Carbonaceous refractory gold ores not only require pretreatment to liberate gold grains, but also require the removal and/or decomposition of carbonaceous matter to …
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DOI: 10.1016/J.MINENG.2004.05.009 Corpus ID: 33480265; A two-stage bacterial pretreatment process for double refractory gold ores @article{Amankwah2005ATB, title={A two-stage bacterial pretreatment process for double refractory gold ores}, author={Richard Kwasi Amankwah and Wan Tai Yen and Juliana A. Ramsay}, …
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Environmentally friendly pretreatment of double refractory gold ores (DRGO) to improve gold recovery without emitting pollutant gas is challenging. Sequential biotreatment, including iron-oxidizing microorganisms to decompose sulfides, followed by the enzymatic decomposition of carbonaceous matter, was recently developed. The …
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The use of alkaline pressure oxidation to pretreat refractory gold ore often results in insufficient gold recovery (<60%) in downstream thiosulfate leaching. To improve gold recovery, flotation was considered …
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Ores in which gold is associated with sulfides and with high carbonaceous matter content are considered double refractory. The northern Nevada region in the …
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The pretreatment of carbonaceous material in double refractory gold ores (DRGO) is necessary to decrease preg-robbing of gold and maximize gold recovery. DRGO contains of carbonaceous matter and gold grains encapsulated in sulfide minerals, which typically results in very poor gold recovery.However, there is growing interest in …
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Double refractory gold ores (DRGO) contain organic carbonaceous matter (CM) and sulfide minerals, and thus require pretreatment before cyanidation for gold extraction. Though there have been several studies into microbial pretreatment of DRGO, available literature indicates that microbial degradation of both sulfides and CM in a single-stage ...
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The term double refractory is applied when refractoriness of the gold ore is exacerbated by the presence of preg-robbing carbonaceous material. The problem of …
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Carbonaceous sulfidic gold ores are commonly double refractory and thus require pretreatment before gold extraction. In this paper, the capacity of pre-bio-oxidation can …
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A brief analysis of the existing and developed methods for processing refractory- and double-refractory gold raw materials showed the futility of focusing on the existing modern technological schemes, which, despite being considered effective, in many cases are fundamentally incapable of providing efficient processing of such ores …
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Besides, gold may be present in ores of that mineragenic type as bi-element clusters of Au-C type as well which is reluctant to cyanation. Formation of AuSx is indicated at the gold surface of double refractory gold ore (sulphide with carbon coatings) in a …
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