2020-6-11 · The results demonstrate that the fungus, P. chrysosporium, is a potential microorganism for oxidative decomposition of metal sulfides associated with refractory gold ores. With improvement in system controls, higher levels of oxidation are feasible.
Request PDF | Fungal pretreatment of sulfides in refractory gold ores | This study assessed the capability of the fungus, Phanerochaete chrysosporium, to decompose pyrite, arsenopyrite and a ...
· title = "Fungal pretreatment of sulfides in refractory gold ores", abstract = "This study assessed the capability of the fungus, Phanerochaete chrysosporium, to decompose pyrite, arsenopyrite and a sulfide-containing flotation concentrate in an effort to develop a microbial process for pretreating refractory gold ores.
56 GMJVol. 17, No. 2, December, 2017 Fungal-Transformation of Surrogate Sulphides and Carbonaceous Matter in Refractory Gold Ores: Revisited* 1G. Ofori-Sarpong, 2D. K. Adjei and 1R. K. Amankwah1 1Minerals Engineering Department, University of Mines and Technology, Tarkwa, Ghana 2Energy and Mineral Engineering Department, Pennsylvania State University, USA ...
2008-11-24 · (P. Afenya, Treatment of Carbonaceous Refractory Gold Ores, Minerals Engineering, Vol. 4, pp. 1043-1055, 1991. W. Guay, The Treatment of Refractory Gold Ores Containing Carbonaceous Material and Sulfides, Society of Mining Engineers of AIME, 81-34, pp. 1-4, 1981). An additional problem in recovering gold from highly carbonaceous ores is that a ...
Refractory carbonaceous sulfide ores are treated in a manner so as to improve gold recovery by a treatment in specific combination of steps whereby the ore is treated with chlorine after pretreatment and before cyanidation; the particular steps in the treatment of the ore have been found to be necessary as the conventional pretreatment will not improve the yields on any economic basis.
2019-7-1 · Double refractory gold ore was sequentially pretreated to oxidize sulfides by thermophilic archaeon Acidianus brierleyi and then to decompose carbonaceous matters using the cell-free spent medium (CFSM) from white-rot fungus Phanerochaete chrysosporium.The pretreatment by A. brierleyi significantly improved the gold recovery from 25% to 77%. . Additionally, the crude lignin-degrading …
Changes in sulfide sulfur concentration and the formation of oxide phases during fungal treatment were confirmed using Raman spectroscopy and X-ray diffraction analysis. These results suggest that P. chrysosporium is a potential microorganism for oxidative decomposition of metal sulfides associated with refractory gold ores.
2008-9-27 · Abstract. The microbiological leaching of refractory sulfide ores (pyrite, arsenopyrite) for recovery of gold is reviewed in this article. The underlying physiological, biochemical, and genetic fundamentals of the bacteria involved (Thiobacillus and Sulfolobus spp.) are complex and have yet to be elucidated in depth.The chemistry of acid and biological leaching of pyrite and arsenopyrite ...
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 aqueous ...
Fungal pretreatment of sulfides in refractory gold ores G. Ofori-Sarpong, K. Osseo-Asare, M. Tien, 2011, Minerals Engineering on p. 499-504
investigated in an attempt to enhance gold recovery from the refractory sulfide gold ores. An oxidative pretreatment of the ore is essential to oxidize the sulfides and expose gold. The conventional methods of extraction of refractory sulfide gold ores usually follow roasting-leaching and electrowinning steps.
2018-8-11 · Pressure oxidation of the refractory sulfide/carbonaceous ores has gained world-wide acceptance. Compared with roasting, pressure oxidation yields higher gold …
2014-6-19 · The majority of the refractory gold and silver occurs in occlusion in sulphides, then precious metal dissolution is possible by first oxidizing auriferous sulfide concentrate using sodium hypochlorite-sodium-hydroxide solution followed of pressure cyanidation of the oxidized concentrate, for the extraction of precious metals. This process was conducted and evaluated under cyanide and oxygen ...
The technological mineralogy of a gold deposit located in North-Western province of Zambia was carried out by using X-ray fluorescence spectroscopy (XRF), X-ray diffraction spectroscopy (XRD), and scanning electron microscope (SEM). The results showed that gold was highly dispersed in gold-bearing minerals such as pyrite, arsenopyrite, and some gangues in the form of natural gold and electrum.
mainly about the refractory gold leaching easily through arsenic removal to expose gold, changing the composition, physic-chemical and electro-chemical properties of the ore. Currently, there are four main methods of pretreatments of refractory gold ores with As. Pretreatment options for deal-ing with refractory gold ores are illustrated in Fig ...
Results indicated that the mechanism of Na 2 SO 4 on double refractory gold concentrate at roasting pretreatment can be summed up in the following three aspects: Firstly, Na 2 SO 4 can react with SO 2 and SO 3 which is produced by the oxidation of sulfides and generate Na 2 S 2 O 7 (l), which plays buffer effect on sulfides exothermic oxidation ...
Fungal pretreatment of sulfides in refractory gold ores. Article. May 2011 ... In the recovery of gold from refractory gold ores, pretreatment is required to decompose sulphides and liberate ...
Gold ores are considered refractory if gold extractions from a conventional cyanidation process are less than 80% even after fine grinding. 1) Arsenic-bearing refractory gold ore has stones extremely difficult to deal with. In the stones, gold is locked up in arsenic mineral matrix as the form of microscopic or submicroscopic lattice.
2020-3-24 · In this study, microbial pre-treatment of double refractory gold ore (sample A) and concentrate (sample B) was investigated using a white-rot fungus, Tramestes versicolor (ATTC 20869). Pulp density, temperature, pH and retention times were the process variables considered.
2021-3-11 · 2.1 Microwave pre- treatment of refractory gold ores . Most of refractory gold occurs within sulphide minerals such as FeS 2 and FeAsS and are treated by roasting, pressure leaching or bacterial leaching to render the gold amenable to recovery by subsequent treatment techniques (Haque, 1987).
2016-3-20 · cause. Gold ores that contain high levels of Au-Ag tellurides have poor solubility in cyanide. Very finely grained inclusions of native gold in sulfides, where the size of gold particles is less than about 10 μm and gold is therefore difficult to liberate, are often refractory.
2018-8-11 · Pressure oxidation of the refractory sulfide/carbonaceous ores has gained world-wide acceptance. Compared with roasting, pressure oxidation yields higher gold extractions from ores or concentrates and enables better handling of environmentally …
2013-12-24 · For extraction of gold from refractory ores or concen- trate, in which gold is surrounded or covered by iron sul- fide minerals, mainly arsenopyrite and pyrite, mineral oxidative pretreatment is essential to oxidize sulfides and to expose gold to the leaching solution. Pyrometallurgi- cal oxidation by roasting is under environmental restric-
2013-5-1 · Double refractory gold ores require pretreatment before gold cyanidation. • Single-stage biotreatment of double refractory gold ore (DRGO) is yet to be a success. • P. chrysosporium simultaneously biotransformed sulfides and carbonaceous matter. • Gold recovery increased substantially after fungal treatment. •
2011-5-1 · 1. Introduction. In sulfidic refractory gold ores, tiny gold particles typically <1 μm (Marsden and House, 2006) may be highly disseminated and locked up within the grain boundaries or fractures of sulfide minerals such as pyrite and arsenopyrite.Thus, decomposition of the sulfides is required to liberate the gold (Baako, 1972, Boyle, 1979, Komnitsas and Pooley, 1989, Benzaazoua et al., 2007).
2010-11-16 · This paper presents the alkaline sulfide pretreatment of an antimonial refractory gold and silver ore. In the ore, gold occurs mainly as gold-silver alloys and as associated with quartz and framboidal pyrite grains, and, to a small extent, as the inclusions within antimonial sulfides. Silver is present extensively as antimonial sulfides such as andorite. Alkaline sulfide pretreatment was shown ...
2016-7-14 · Metallurgical ContentGold Leaching & Processing of Arsenic OreMispickel (Arsenopyrite: FeAsS).6Leaching and Recovering Gold from Antimony MineralsStibnite (Antimony Sulphide, Sb2S2)Telluride Gold Ore ProcessingSolubility of TelluridesGold …
