Pretreatment of refractory ores in gold leaching process con

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  • OBORTS Company, Opposite the residence of old General Mambou, Near Dragage, Bastos, Yaoundé, Cameroon
    Email: [email protected]

  • Microbial Pretreatment of Refractory Gold Ore - Xinhai

    Mar 28, 2016· Microbial Pretreatment of Refractory Gold Ore. 2016-03-28 17:59:31 XinHai (1801) For coarse grain size of gold after crushing and grinding by flotation, gravity concentration, cyanide leaching process or several process combined treatment will be able to complete the separation of gold and gangue minerals, but there are some curing refractory

  • ALTA MetBytes - What's Happening in Gold Ore Processing

    Rapid Oxidative Leach (ROL) Process . FL, USA, is developing the application of their mechano-chemical pre-treatment process to oxidize refractory sulphide gold ores and concentrates under atmospheric pressure without ultrafine grinding and at temperatures much lower than traditional roasting or autoclave pre-treatment(14). 2019. . .

  • Review Pretreatment Process on Refractory Gold Ores with As

    reach it in cyanide leaching process. 2) The gold ores with As must be broken or decomposed in the gold particles scales, so that gold is fully exposed, and then extracted with the appropriate gold leaching agent. The process of crushing or decomposition before gold leaching is called pretreatment of refractory gold.

  • Gold extraction - QueensMineDesignWiki

    Figure 5 - Refractory Ore Pretreatment Options. In order to choose a pretreatment option for a refractory ore, the main concern is attaining a solution which succeeds in preparing the ore for cyanidation, whilst remaining economically feasible. Mill Sizing. The ore throughput rate of a mill is largely dependent on the mining production rate.

  • Pretreatment Process on Refractory Gold Ores with As

    The process of crushing or decomposition before gold leaching is called pretreatment of refractory gold. Statistics show that, in the world, about 2/3 gold resource belongs to the difficult processing ores, and about 1/3 total output of world gold is produced from refractory gold. This proportion will further increase in future.

  • Process for treating refractory gold ores by roasting

    Microscopic gold inclusions in sulfide minerals cannot typically be extracted by conventional cyanidation. The gold ore must be pretreated to oxidize sulfide minerals associated with gold and to remove other minerals and chemical compounds that interfere in the cyanidation leaching process. The recovery of gold from refractory sulfidic-carbonaceous ores after roasting pretreatment was studied.

  • Effect of Pretreatment of Sulfide Refractory Concentrate

    A clear boundary between refractory and non-refractory ore in terms of gold recovery is not well defined, but several authors have pointed out that less than 60% gold recovery by direct cyanide leaching, after fine grinding of mineral indicates a refractory mineral [1]. The refrac- tory ore must be destroyed or attacked by chemical

  • US4559209A - Leaching refractory gold ores - Google Patents

    A method is disclosed for leaching a gold ore which is refractory due to the presence of sulphide minerals of arsenic and antimony. The ground ore is leached with cyanide in a pipe reactor at a pressure of between 5 and 8 MPa. The terminal pH value of the pulp is controlled to be 10 or less than 10.

  • Developments in the pretreatment of refractory gold

    submicroscopic gold inclusions within sulphide minerals such as arsenopyrite and pyrite. Such ores require a pre-treatment process to alter or destroy the sulphide matrix and render the gold accessible to cyanide and oxygen (Gudyanga et al., 1999). The gold in high-sulphur and high-arsenic refractory gold concentrate (HGC) is encapsulated

  • Research status of carbonaceous matter in carbonaceous

    The gold ores mainly are categorized into two types: non-refractory and refractory. With the increasing exhaustion of non-refractory gold ores, refractory gold ores have become main materials of the gold industry, and nearly one third of gold comes from refractory gold ores all over the world [1]. Carbonaceous refractory gold

  • CA1293858C - Method for the recovery of gold using

    ABSTRACT A gold recovery pretreatment process is disclosed in which the gold content is more completely extracted from refractory sulfidic ores which contain large quantities of metal carbonates such as dolomite than occurs in traditional gold extraction methods. The process includes treating the ore in an autoclave at elevated temperature and oxygen overpressure conditions in the presence of

  • A two-stage bacterial pretreatment process for double

    A two-stage bacterial pretreatment process for double refractory gold ores R.K. Amankwah a,*, W.-T. Yen a, J.A. Ramsay b a Mining Engineering Department, Queen’s University, Kingston, Ontario, Canada K7L 3N6 b Chemical Engineering Department, Queen’s University, Kingston, Ontario, Canada K7L 3N6 Received 7 April 2004; accepted 11 May 2004 Abstract Double refractory gold …

  • How to Improve the Refractory Gold Leaching Process? - Xinhai

    Aug 18, 2020· 01 One. Pretreat the refractory gold. The gold leaching rate of most refractory gold ores is about 10% ~ 20% when they are directly stirred by sodium cyanide. Generally, the gold leaching rate of refractory gold ore can be greatly improved by pretreating the raw materials, including oxidative roasting, hot-pressure oxidation, biological oxidation.

  • Pretreatment of a refractory arsenopyritic gold ore using

    Mar 01, 2015· An arsenopyrite refractory ore was pretreated with NaOH to increase gold extraction. After pretreatment, gold and silver were leached with copper ammonium thiosulfate solution. Thiosulfate leaching of the as-received ore extracted only 21% and 29% of silver and gold, respectively. Up to 81% of the gold and 50% of the silver were recovered after

  • Establishing thE ProcEss MinEralogy of gold orEs

    available to gold process mineralogy, introduce the procedure employed at SGS Lakefield Research, and provide some case studies to give a complete picture of gold process mineralogy. gold orEs and MinErals gold orE tyPEs Gold ores are commonly classified by the metallurgist into two major categories: free-milling and refractory ores.

  • Refractory gold ores: Challenges and opportunities for a

    Mar 23, 2021· Gold miners are facing a reserves crisis, and what is left in the ground is becoming more and more challenging to process.Refractory gold reserves, which require more sophisticated treatment methods in order to achieve oxide-ore recovery rates, correspond to 24 percent of current gold reserves and 22 percent of gold resources worldwide (Exhibit 1).

  • Improved gold and silver extraction from a refractory

    Jan 01, 2011· The pretreatment of an antimonial refractory gold and silver ore was investigated using alkaline sulphide leaching. The ore assayed 20 g/t Au and 220 g/t Ag and contained predominantly quartz/clay and barite, and to a lesser extent, sulphides such as pyrite, stibnite, sphalerite, zinkenite (Pb 9 Sb 22 S 42) and andorite (Sb 3 PbAgS 6).The latter mineral was identified to be the most important

  • pretreatment of refractory ores in gold leaching process congo

    reach it in cyanide leaching process. 2) The gold ores with As must be broken or decomposed in the gold particles scales, so that gold is fully exposed, and then extracted with the appropriate gold leaching agent. The process of crushing or decomposition before gold leaching is called pretreatment of refractory gold.

  • (PDF) A Preliminary Study on Nitric Acid Pre-treatment of

    This study was undertaken to evaluate the nitric acid leaching as a potential pre-treatment process prior to cyanidation of refractory gold/silver ores. The nitric acid pre-treatment experiments

  • Gold extraction - Wikipedia

    These refractory ores require pre-treatment in order for cyanidation to be effective in recovery of the gold. A refractory ore generally contains sulfide minerals, organic carbon, or both. Sulfide minerals are impermeable minerals that occlude gold particles, making it difficult for the leach solution to form a complex with the gold.

  • OPTIMISATION OF ROASTING OF ARSENIC- CARBON …

    Optimisation of roasting of arsenic-carbon refractory gold ores for cyanide leaching 61 In the course of pilot tests, the process parameters were changed, in which there was the variation of material retention time in the kiln (1–4 hours), ore grain size

  • Studies on the bioleaching of refractory concentrates

    for the pre-treatment of refractory gold ores and concentrates and the leaching of whole-ore copper heaps. In many cases, it offers economic, environmental and technical advantages over pressure oxidation and roasting1,2. However, in order for bioleaching to compete successfully with other pre-treatment processes it needs to be optimized with

  • Improvement of Gold Leaching from a Refractory Gold

    A total gold extraction of 70.2% could only be reached via direct cyanidation from a refractory As-, S- and C-bearing gold concentrate calcine, and the gold extraction varied noticeably with different size fractions. The reasons for unsatisfactory gold extraction from the calcine were studied through analyses of chemical composition, chemical phase and SEM-EDS of different sizes of particles.

  • Microwave pretreatment of a double refractory gold ore

    Abstract 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 refractory gold ore was investigated as an

  • Gold Leaching from Refractory Ores—Literature Survey

    Apr 27, 2007· However, pretreatment processes involving thermal oxidation, such as roasting, chemical oxidation, such as acid leaching, acid or alkaline pressure leaching; or biological oxidation such as bioleaching with T. Ferrooxidans liberates gold from refractory minerals. Gold is then recovered from the oxidized mass by alkaline cyanidation.

  • Biooxidation‒thiosulfate leaching of refractory gold

    Jul 21, 2019· A process of biooxidation followed by thiosulfate leaching of gold from refractory gold concentrate was investigated. Mineralogical studies on the concentrate showed that very fine gold grains (<10 μm) were encapsulated in pyrite and arsenopyrite, while the proportion of monomer gold …

  • Recovery Refractory Resources - SGS

    are driven by the gold recovery rate. The pre-treatment of refractory gold ore should increase the gold recovery rate in the cyanide leach process by 30-40% in order to be economical” “Large operations tend to choose roasting or pressure oxidation, while smaller operations tend to select bacterial leaching,” says Dr Fleming. “Other

  • Improvement of Gold Leaching from a Refractory Gold

    energy consumption. As a result, proper pretreatments are necessary to improve the leaching of gold from these refractory gold ores [5,6]. The pretreatment of oxidative roasting has always been one of the most extensively used methods in China attributing to its mature technique, high efficiency, energy conservation, etc. [7,8] Effective

  • Effect of Pretreatment on Leaching Primary Copper Sulfide

    The pretreatment leaching process obtained 91.6% Au compared to 67.3% Au for leaching without pretreatment. The bio-oxidation stage improves metal recovery. Qiu et al. [15] developed a cyanidation process with a pretreatment stage for silver and gold recovery from a refractory Au–Ag ore. The pretreatment used pyrite as a reductant where MnO2

  • Treatment of copper-rich gold ore by cyanide leaching

    Treatment of copper-rich gold ore by cyanide leaching, ammonia pretreatment and ammoniacal cyanide leaching A. D. BAS, E. KOC, E. Y. YAZICI, H. DEVECI Hydromet-B&PM Group, Division of Mineral & Coal Processing, Department of Mining Engineering, Karadeniz Technical University, Trabzon 61080, Turkey Received 28 March 2014; accepted 1 September 2014

  • (PDF) Implementation of sodium hydroxide pretreatment for

    Implementation of sodium hydroxide pretreatment for refractory antimonial gold and silver ores. Hydrometallurgy, 2011. PDFs related to this paper. READ PAPER. Implementation of sodium hydroxide pretreatment for refractory antimonial gold and silver ores from a refractory antimony ore by pretreatment with alkaline sulphide leach.

  • Application Note Refractory Gold Pretreatment - pH

    Refractory Gold Pretreatment - pH Mining: Gold Processing Refractory gold ores are defi ned as containing minerals or carbon compounds that trap encapsulated gold and make leaching extraction diffi cult. These types of ores require pretreatment prior to cyanidation. Options for pretreatment include the following processes: • Roasting

  • Refractory Gold Ore Treatment Methods

    Jul 14, 2016· 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 Extraction from Carbonaceous OreList Gold Refractory Process Methods Where gold is associated with arsenic, antimony, tellurium, and …

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

    Bacterial leaching as a pre-treatment step for gold recovery from refractory ores Stirred reactor bio-leaching processAn important feature of bio-leaching as applied to refractory gold ores is the distinction that can be exploited between the relative reaction rates of gold-bearing sulphides. bio-leaching is rather a slowly process. If

  • CHLORIDE HYPOCHLORITE OXIDATION AND LEACHING OF …

    (Fig. 4). Major elements composition of the ore and floated concentrate are presented in Table 1. As shown in this table, by flotation of the ore with 3.770 g/Mg gold, a con-centrate containing 20.451 g/Mg gold was obtained. After 24 hours, direct cyanide leaching of the initial ore resulted in only 54.8% gold …

  • pretreatment of refractory ores in gold leaching process congo

    Pretreatment Process on Refractory Gold Ores with As. 2 The gold ores with As must be broken or decomposed in the gold particles scales so that gold is fully exposed and then extracted with the appropriate gold leaching agent The process of crushing or decomposition before gold leaching is called pretreatment of refractory gold.

  • Methods of Processing of the Gold-Containing Refractory

    conditions of gold leaching by means of thiourea method from the above-mentioned ores and concentrates with 85-90% gold extraction were established. Investigations were carried out on electrochemical leaching of refractory gold-containing sulfide ores and concentrates. We used the acid chloride electrolyte, which

  • PAPER OPEN ACCESS Biooxidation pretreatment of low …

    tailings. In addition, the gold leaching process does not undergo optimally if gold ore that is processed is refractory. Gold minerals are called refractory when gold metal particles are very small (50 μm in diameter) and are included in carbonaceous minerals, sulfides, tellurides, and cyanicides. With the presence of these minerals, the

  • MODELING OF HIGH PRESSURE PRETREATMENT PROCESS …

    Keywords: pretreatment process, pressure oxidation, refractory gold ore and concentrate, leaching, modeling Investigation of high pressure pretreatment process for gold leaching is the objective of the present master's thesis. The gold ores and concentrates which cannot be easily treated by leaching process are called "refractory".

  • Leaching Guide of Refractory Gold Ore

    Feb 28, 2020· 1.What Is Refractory Gold Ore? With the development of beneficiation technology, the definition of refractory gold ore is changing. Generally speaking, refractory gold ore in leaching field is a kind of ore whose leaching rate of gold is less than 80% when directly processed by cyanidation after find grinding.

  • 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.

  • BACTERIAL LEACHING AS A PRE-TREATMENT STEP FOR …

    There are two general methods of bacterial leaching in gold hydrometallurgy. These are both stirred reactor bio-leaching process and bio-heap leach process. This article will focus upon the stirred reactor bio-leaching process. Stirred reactor bio-leaching process An important feature of bio-leaching as applied to refractory gold ores is the