A multidisciplinary approach has been used to study Au occurrences within pyrite and arsenopyrite in four refractory Au ores from Colombia, France (Le Châtelet and Villeranges) and Portugal (Neves Norte).Web
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A pressure oxidation procedure that has gained commercial status for treating gold-bearing arsenopyrite or pyrite employs sulfuric acid (H2SO4) and oxygen as reagents. High temperatures (170° to 190° C) and pressures (up to 400 psig O2) are required to achieve complete oxidation of the sulfide minerals. The chemistry of these …Web
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The chemical composition of various pyrites and arsenopyrites from gold-bearing quartz veins, disseminated pyrite-arsenopyrite-sericite-quartz mineralized slate with different orientation and intense mineralized breccia were determined by LA-ICPMS on a suite of 8 representative samples (Table 1).Web
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A gold bearing arsenopyrite concentrate was characterised, and found to consist of 70% arsenopyrite and 25% pyrite with a small amount of stibnite and silicate minerals. On cyanide leaching only 6% of gold was extracted. Of the remainder, the gold associated with the arsenopyrite fraction was in solid solution, as was some of the gold …Web
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Due to geochemical similarity between arsenic and sulphur, polymetallic sulphide deposits and pyrite/arsenopyrite-bearing coal beds often contain exceptionally high concentrations of arsenic. Arsenic release from mine waste occurs after oxidative dissolution of sulphide minerals. Both arsenite and arsenate forms coexist in many mine …Web
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Pyrite is another common gold-bearing mineral and often intergrown with arsenopyrite [11]. The effect of pyrite on leaching of arsenopyrite cannot be ignored. According to the measured rest potentials of sulfide minerals [12], the rest potential of arsenopyrite is lower than that of pyrite.Web
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All types of arsenopyrite contain gold (1250–3000 ppm) and other trace elements such as Cu (200–1300 ppm), Sb (up to 9000 ppm) and Tl (3000–4500 ppm). …Web
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To be common, sulfide minerals in nature, pyrite and arsenopyrite, are often associated with other metal sulfide ore. At the same time, they are also the carrier minerals of some rare metals such as gold, silver, and platinum group metals [1–3].Pyrite and arsenopyrite are the desired minerals for gold-bearing sulfide ore flotation.Web
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Effect of Au status on ion emission rate Comparison with EMPA analyses The SIMS depth profiles of pyrite and arsenopyrite Au-bearing grains (Fig. 7) show that the first Figure 9 shows grade profiles obtained by SIMS mineral layers enhance Au emission during the Au and EMPA analysis, superimposed for compar- SIMS analysis: steady state is ...Web
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Separation of gold-bearing arsenopyrite from barren pyrite. When attempting to concentrate submicroscopic and in particular solid–solution gold, it is important to keep in mind the following two peculiarities of the host sulfides: ... Similar to pyrite, arsenopyrite oxidation is a three-step electrochemical process involving cathodic reaction ...Web
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arsenopyrite and pyrite as the major sulphide minerals. The ABA confirmed that the gold sulphide ore could be a potential source of AMD with respect to AMD marginal of safety if the ore is left ...Web
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Au speciation in sulfides (including "invisible" Au), which mostly controls the loss of Au during ore dressing, is discussed. Modern methods of analysis of Au speciation, with discussion of limitations by locality and sensitivity, are reviewed. The results of sulfide investigation by the methods of scanning and transmission electron microscopy, mass …Web
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Notwithstanding, in the separation of gold bearing sulphides during froth flotation, a concentrate made up of both pyrite and arsenopyrite is obtained due to their similar characteristics and ...Web
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Pyrite and arsenopyrite occur as ten and four texturally distinct subtypes; all host invisible gold, which is lattice-bound. Trace element mapping of selected pyrite and …Web
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The arsenopyrite and pyrite are the main objects for analytical study of gold-bearing sulfide minerals, their different textures, morphology of the crystals and aggregates. The studies of ore...Web
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Metallic minerals are dominated by pyrite, arsenopyrite (Fig. 3 b–g), native gold, and minor sphalerite, galena, chalcopyrite, tetrahedrite and pyrrhotite. Gangue minerals consist mainly of quartz, ankerite, sericite and chlorite. ... Thirty-three pyrite-bearing samples were collected from the drill cores (ZK0304, ZK0703, ZK3502, ZK3507 …Web
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The Gutaishan deposit is a slate-hosted lode Au–Sb deposit in the Xiangzhong Sb–Au metallogenic province, South China. The deposit has a proven reserve of ca. 9 -t gold at an average grade of 13-g/t and contains 2500-t Sb. The deposit represents the product of a complex ore-forming process, comprising four different stages, of which …Web
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Fleet, M.E., Mumin, A.H. (1997) Gold-bearing arsenian pyrite and marcasite and arsenopyrite from Carlin-trend gold deposits and laboratory synthesis. American Mineralogist: 82: 182-193. Maddox, L.M. et al. (1998) Invisible gold: Comparison of Au deposition on pyrite and arsenopyrite.Web
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Based on its paragenetic association with pyrite, arsenopyrite was mostly arranged radially at the edges of the pyrite (Figs. 3C, 4B, and 4D), and formed later than some pyrite, which is consistent with observed sequences among Au-bearing minerals in Carlin-type Au deposits (Ohmoto and Rye 1979; Chen et al. 2009). Moreover, the Baidi …Web
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Moreover, a slightly negative correlation between the Au and Fe is observed in the compositions of Au-bearing pyrite and arsenopyrite crystals, and the Au/As values are below the solubility limit ...Web
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Pyrite Arsenopyrite: Biooxidation tank reactors (Rawlings et al., 2003) Chuquicamata, Chile (planned) ... High level arsenic resistance in bacteria present in biooxidation tanks used to treat gold-bearing arsenopyrite concentrates: a review. Trans. Nonferr. Met. Soc. China, 18 (6) (2008), pp. 1311-1318.Web
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We suggest that invisible gold in arsenian pyrite and marcasite and arsenopyrite from sediment-hosted gold deposits represents Au removed from ore fluids …Web
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The results from TD tests, carried out on pure copper minerals (chalcopyrite, arsenopyrite, chalcocite, digenite, bornite, covellite, enargite, and tennantite) showed a broad range of copper releases.All TD time series for the copper-bearing minerals (except digenite) displayed a good fit with a second-order release model, indicating the participation of at …Web
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In both lithologies, euhedral pyrite and arsenopyrite coexist with quartz and ankerite, but chalcopyrite, galena, sphalerite and others are also present, to a lesser extent. Download : Download high-res image (1MB) Download : Download full-size image; ... the sulfur isotopic characteristics of gold-bearing pyrite, and paucity of regional ...Web
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Calculated As concentrations in equilibrium with the pyrite–arsenopyrite assemblage in the surficial environment are 0.01–0.1 ppm, similar to groundwater in arsenopyrite-bearing rocks in this study (0.005–0.3 ppm), and these waters may be in chemical equilibrium. Arsenopyrite decomposes in oxidised waters to yield up to 1100 …Web
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Arsenopyrite and pyrite are the most common Au-bearing minerals in various Au deposits (Large et al., 2007;Bi et al., 2011;Cook et al., 2013). Major and trace elements in arsenopyrite and pyrite ...Web
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Gold-bearing arsenian pyrite and marcasite and arsenopyrite from Carlin Trend gold deposits and laboratory synthesis. Abstract Invisible gold in natural and synthetic arsenian pyrite and marcasite correlates with anomalous As content and Fe deficiency, and high contents of invisible gold in most natural and all….Web
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Biooxidation of gold-bearing arsenopyrite concentrates, using acidophilic microbial communities, is among the largest commercial biohydrometallurgical processes. However, molecular mechanisms of microbial responses to sulfide raw materials have not been widely studied. The goal of this research was to gain insight into the defense …Web
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Abstract. A multidisciplinary approach has been used to study Au occurrences within pyrite and arsenopyrite in four refractory Au ores from Colombia, France (Le …Web
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The Shuiyindong Carlin-like gold deposit, the largest one of this type in China, is located in the Late Paleozoic–Early Mesozoic Youjiang basin. The pyrites in the studied ore bodies (No. I to V) can be divided into four main types plus several sub-types: (1) As-poor pyrites include Py1 (Py1a and Py1b), Py2, and Py3; and (2) As-rich pyrite Py4 …Web
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Trace-element geochemistry of pyrite and arsenopyrite: ore genetic implications for late Archean orogenic gold deposits in southern India. Mineralogy, …Web
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Pyrite and arsenopyrite occur as ten and four texturally distinct subtypes; all host invisible gold, which is lattice-bound. ... change, rele asing of T e and formatio n of T e-bearing mine rals ...Web
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The ore minerals mainly consist of native gold, pyrite, arsenopyrite, galena, sphalerite, and chalcopyrite, and the gangue minerals comprise quartz, calcite, albite, ankerite, chlorite, epidote, and sericite. ... The middle-stage Py2c is also an important gold-bearing pyrite type, as its Au content ranges from 0.18 to 18.0 ppm, with a median of ...Web
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Later, after particular dissolution of pyrite-1, Au-rich As-bearing pyrite-2 and arsenopyrite precipitated. These facts suggest a marked increase in the arsenic and gold activities in ore-bearing fluids. The As-content of pyrite-2 decreases in an oscillatory manner from the core to the rim, reflecting changes in the As activity or/and in the P ...Web
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Gold bonding in arsenopyrite, examined by transmission electron microscopy, is shown to be dispersed within the FeAsS crystal structure. Typical growth patterns and …Web
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Pyrite-mediated arsenopyrite oxidation is an important process affecting arsenic (As) mobility. The iron sulfides-induced reactive oxidation species (ROS) can exert significant influence on As transformation. However, the impact of pyrite-arsenopyrite association on ROS production and its contribution to As transformation were rarely …Web
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