oxidation of refractory minerals

  • ACID PRESSURE OXIDATION OF REFRACTORY GOLD MINERAL ...

    Jan 01, 1987· Pressure oxidation of these refractory gold mineral carriers is a very complex reaction system involving several oxidation and hydrolytic reactions which occur in series and/or parallel. Moreover these oxidation reactions are highly exothermic. Since the nature and composition of the reaction products can have a considerable impact on the ...

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  • (PDF) Oxidative Hydrometallurgy of Sulphide Minerals

    The refractory sulfide gold ores in which gold is surrounded by sulfide minerals, oxidative pretreatment of the ore is important to oxidize the sulfides and expose the gold (Carrillo-Pedroza et al ...

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  • Oxidation studies of some refractory metals

    Oxidation studies of some refractory metals Abstract Samples of niobium, tantalum, molybdenum and tungsten metals have been given phosphided cases by heating in a phosphorous atmosphere. The samples were subsequently exposed to air at an elevated temperature. In tests at 800°C, the phosphided samples resisted air oxidation markedly compared to ...

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  • Issues affecting heap biooxidation of low-grade refractory ...

    These sulfate mineral accumulations locally reduce permeability and may channel the oxidizing solution and induced airflow as well as limiting diffusion within the aggregate itself resulting zones of reduced oxidation and therefore reduced gold recovery.

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  • Pressure Oxidation of a Refractory Sulfide Concentrate and ...

    Significant advances have taken place in the treatment of refractory gold ores and concentrates during the past decade. In sulfide ores, pyrite is the most common host mineral for gold. Studies by Gasparrini (1983) showed that gold occurs in pyrite as native gold or electrum in all sizes and forms. Arsenopyrite is probably the second most common host for gold and forms similar associations ...

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  • The Leachox™ Refractory Gold Process – The Testing, Design ...

    Oxidation . ABSTRACT . The Leachox refractory gold process has to date been applied to the selectivetreatment of several refractory gold ores but on a relatively small scale. In this paper the successful implementation of the process, from initial testing through to commissioning at one of the world's largest refractory gold mines is described.

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  • Bioleaching review part B: | SpringerLink

    Oct 18, 2003· This review describes the historical development and current state of metals leaching and sulfide mineral biooxidation by the minerals industries. During the past 20 years commercial processes employing microorganisms for mineral recovery have progressed from rather uncontrolled copper dump leaching to mineral oxidation and leaching in designed bioheaps for oxidation of refractory gold …

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  • Sun High Pressure Oxidation Of Refractory Gold Minerals

    Sulfide Iron Leaching For Gold Recovery Flowsheet. Pressure Oxidation Of Refractory Gold Ores The 2014101Pressure oxidation is employed to liberate gold and silver in refractory sulfide concentrates often and ores The main pressure oxidation products from iron sulfide minerals are sulfuric acid and metal sulfates and hematite Depending on the conditions within the autoclave acid containing

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  • Pretreatment Process on Refractory Gold Ores with As

    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.

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  • Atmospheric alkaline pre-oxidation of refractory sulphide ...

    Four iron-sulphide-containing gold ores from the White Mountain mine in the Jilin Province, China were studied to examine the benefits of using oxidative treatment prior to conventional cyanidation to leach gold. This pre-treatment consisted of bubbling air into an ore/water mixture for eight hours while adding enough caustic sodium hydroxide to maintain a pH of 11 throughout the test. Three ...

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  • Microbial oxidation of gold ores and gold bioleaching ...

    This paper reviews recent progress in the use of microorganisms tooxidize the sulfidic matrix in refractory gold ores (bio-oxidation) and to solubilize elemental gold (bioleaching). Arsenopyrite oxidation, Bioleaching, Biohydrometallurgy, Pyrite oxidation, Refractory …

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  • (PDF) Bacterial leaching as a pre-treatment step for gold ...

    Such ores are known as refractory ores (Attia and El-Zeky, 1989).Various pre-oxidation methods of refractory ores and concentrates are commonly used to improve precious metal recoveries. For example, oxidative roasting has been used in some cases as a pre-oxidation step before cyanidation.

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  • Gold recovery from refractory gold concentrates by ...

    Abstract: Naturally, refractory gold is enclosed by sulfide minerals such as pyrite and arsenopyrite and a higher content of organic carbon, which results in difficulty in the recovery of gold. In this study, the

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  • Biooxidation - BioMineWiki

    "In refractory ores, small particles of gold are covered by insoluble sulfides impeding the contact between cyanide and gold. In this case, a pretreatment stage must be considered, such as pressure oxidation, chemical oxidation, roasting or bio-oxidation, the latter currently being

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  • POX Oxidation of refractory gold ore - Hydrometallurgy ...

    Hi as you know one of the method for treatment of refractory gold ore is POX. could you please explain about the limitation of S content in the concentrate? because I found in a Chinese text that the maximum content of S in the sulfide concentrate not be more than 10%. if it is true, please tell

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  • Refractory metals - Wikipedia

    Refractory metals are a class of metals that are extraordinarily resistant to heat and wear.The expression is mostly used in the context of materials science, metallurgy and engineering.The definition of which elements belong to this group differs. The most common definition includes five elements: two of the fifth period (niobium and molybdenum) and three of the sixth period (tantalum ...

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  • Bio-Oxidation and Biocyanidation of Refractory Mineral ...

    Bio-Oxidation and Biocyanidation of Refractory Mineral Ores for Gold Extraction: A Review October 2014 Critical Reviews in Environmental Science and Technology 45(15)

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  • Developments in the pretreatment of refractory gold ...

    processing refractory gold ores, especially development in the pretreatment of refractory gold minerals by nitric acid. These processes include the high-pressure and the atmospheric-pressure oxidation methods. High-pressure oxidation processes are difficult …

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  • Bio-Oxidation and Biocyanidation of Refractory Mineral ...

    (2015). Bio-Oxidation and Biocyanidation of Refractory Mineral Ores for Gold Extraction: A Review. Critical Reviews in Environmental Science and Technology: Vol. 45, No. 15, pp. 1611-1643.

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  • Pressure oxidation - Wikipedia

    Pressure Oxidation is a process for extracting gold from refractory ore.. The most common refractory ores are pyrite and arsenopyrite, which are sulfide ores that trap the gold within them.Refractory ores require pre-treatment before the gold can be adequately extracted. The pressure oxidation process is used to prepare such ores for conventional gold extraction processes such as cyanidation.

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