Artykuły w czasopismach na temat „Gold ores”
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1
Vaughan, J. P., i A. Kyin. "Refractory gold ores in Archaean greenstones,Western Australia: mineralogy, gold paragenesis, metallurgical characterization and classification". Mineralogical Magazine 68, nr 2 (kwiecień 2004): 255–77. http://dx.doi.org/10.1180/0026461046820186.
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AbstractMesothermal gold ores in the Archaean Yilgarn Craton of Western Australia are dominated by a pyrite ± arsenopyrite ± pyrrhotite sulphide assemblage. Many of these ores are refractory to varying degrees and require treatment by roasting, bacterial oxidation or finer milling. The most common sulphide ore types can be sub-divided broadly into pyritic (pyrite±pyrrhotite) and arsenical types (pyrite+arsenopyrite± pyrrhotite). Arsenical ores vary from highly refractory to free-milling. Arsenopyrite in highly refractory ores is finer grained, As-deficient (27 –32.5 at.% As), contains high average concentrations of submicroscopic gold (60 –270 ppm), but does not contain inclusions of particulate gold. Arsenopyrite in free-milling ores is coarser grained, less As-deficient to slightly As-rich (30 –35 at.% As), contains low or negligible concentrations of submicroscopic gold, but contains inclusions and fracture fillings of particulate gold. In some refractory arsenical ores, pyrite also contains moderately high levels of submicroscopic gold (20 –40 ppm), the concentration of which is directly related to As content of the pyrite.Pyritic ores are free-milling to mildly refractory, or rarely moderately refractory. Pyrite in pyritic ores contains negligible to low levels of submicroscopic gold (<5 ppm). Other reasons for refractory behaviour in pyritic ores include very fine-grained native gold inclusions in pyrite, or the presence of gold-bearing tellurides.It is concluded that submicroscopic gold is incorporated into the crystal lattices of arsenopyite and arsenical pyrite at sub-greenschist to lower greenschist-facies temperatures, and is progressively expelled as inclusions and fracture fillings of native gold in sulphides, and ultimately into the gangue, as recrystallization proceeds through upper greenschist- into amphibolite-facies temperatures, during deformation and burial. Submicroscopic gold is expelled more rapidly from pyrite than arsenopyrite.Pyrrhotite progressively replaces primary pyrite at higher temperatures, but rarely contains gold. Finally, a metallurgical classification scheme for refractory ores is presented which incorporates the above mineralogical conclusions.
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DVORNIK, Gennadiy Petrovich. "Conformities distribution contents gold and silver in ore bodies of the Berezovskoe deposit (Middle Urals)". NEWS of the Ural State Mining University, nr 4 (15.12.2023): 55–68. http://dx.doi.org/10.21440/2307-2091-2023-4-55-68.
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The relevance of the work is due to the importance industrial meaning associated with beresits and listvenites gold ores deposit in the world production. Purpose of the work – study conformities of distribution gold and silver concentration in ore bodies of the Berezovskoe deposit. Methods of research included separation industrial types of ores for valuation quality gold chute, use probabilistic-statistic, geometric-statistic and geostatistic models for description amplitude and frequency changeability gold and silver content in ore bodies of Berezovskoe deposit. Results. It was established definite conformities in distribution contents gold and silver in primary types ores of Berezovskoe deposit. So in limits mineralized dikes granitoids on percentage correlation rich, ordinary and poor ores, meaning coefficients wealth and the gold-silver ratio the best quality distiquished sulphide-quartz ores in the strip veins in comparison with more poor impregnation ores in berezites near veins. In distribution parameters gold mineralization (contents gold and silver, linear productivity of ores) was established tier vertical zonality with separation 2–3 levels the largest foul prevalence mineralization on dip dikes granitoids in interval of depth 112–712 meters. In distribution contents gold and silver in ores registered lateral zonality on strike ore-bearing dikes granitoids. She expressed in conforming growth productivity of ores on horizons with moving off in direction with south to the north from the contact Shartash massif of granitoids. Distribution gold and silver content in mineralized dikes granitoids on amplitude variability changed from quite uneven to extremely uneven. Among colour sulphide-quartz veins of Berezovskoe deposit on content in their gold and silver, linear productivity of ores the best quality defined veins, formed on upper ore level (53–168 m). Quality ores conforming lowered with growth of depth bedding veins on middle ore level (201–262 m) and lower ore level (442–512 m) horizons.
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Abramov, B. N. "Peculiarities of the distribution of rare-earth elements in the ores of some gold deposits of Eastern Transbaikalia". Proceedings of higher educational establishments. Geology and Exploration, nr 5 (2.11.2018): 48–58. http://dx.doi.org/10.32454/0016-7762-2018-5-48-58.
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The distribution of rare-earth elements (REE) in ores of gold deposits of East Transbaikalia has shown that the ore-bearing magma chambers have different depths and degrees of differentiation. The greatest degree of differentiation was within the magmatic foci (Eu/Eu* — 0,29—0,32; Rb/Sr — 0,98—1,40), which are the sources of gold-quartz-arsenopyrite ores, the magmatic sources of the gold-quartz and gold-sulfide-quartz ores (Eu/Eu* — 0,53—0,72; Rb/Sr of 0,10 to 0,54) had lesser degree of differentiation. Magma chambers that are sources for the gold-quartz-arsenopyrite ores (Eu/Sm — 0,08—0,14), were at shallower depths than those for gold-quartz and gold-sulfide-quartz ores (Eu/Sm — 0,11—0,19). The formation of gold-quartz-arsenopyrite ores took place at the magma chambers, largely enriched in volatile components, it is indicated by the existence of a significant tetrad effects in REE patterns of (T1-4 - 0,80; 1,15; 1,16).
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Keedy, C. R., L. Parson i J. Shen. "Determination of gold in gold ores". Journal of Radioanalytical and Nuclear Chemistry Letters 137, nr 3 (październik 1989): 191–99. http://dx.doi.org/10.1007/bf02167774.
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Amdur, A. M., R. A. Apakashev, S. Ya Davydov i N. G. Valiev. "The extraction of the associated precious metals out of the construction industry's complex ores". NOVYE OGNEUPORY (NEW REFRACTORIES), nr 8 (27.12.2018): 20–23. http://dx.doi.org/10.17073/1683-4518-2018-8-20-23.
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The effective processing methods were investigated for the precious associated components extraction out of the ores by means of the physical and chemical and the chemical and metallurgical enrichment integration. It was established experimentally that the gold's disperse drops melted by means of the external heat source moved to the ore's surface through the pores under the thermocapillary pressure influence. After the enclosing rocks melted the gold drops were floated by the gas bubbles. The pyrometallurgical device was developed to extract the dispersive gold out of the complex ores in the course of the cast refractory materials processing.Ill.3. Ref. 5.
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Bulaev, Aleksander, Zylikha K. Kanayeva, Maxim I. Muravyov, Ashimkhan T. Kanayev i Tamara F. Kondrat'eva. "Column Bioleaching of Refractory Gold Ores". Advanced Materials Research 1130 (listopad 2015): 459–62. http://dx.doi.org/10.4028/www.scientific.net/amr.1130.459.
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Refractory sulfide ores are ubiquitous resources of gold around the world. It was demonstrated that biooxidation pretreatment of refractory whole ores could be conducted in heaps. The effectiveness of column biooxidation of off-balance gold ores from Bakyrchik and Bolshevik deposits (northeast Kazakhstan) containing pyrite and arsenopyrite was examined in the laboratory. Bakyrchick ore contained 1.5% of pyrite, 3% of arsenopyrite and 4.5 g/t of gold. Bolshevik ore contained 1% of pyrite, 1% of arsenopyrite and 10.7 g/t of gold. The recovery rates of gold from the Bakyrchik and Bolshevik ores by direct cyanidation were 4.5% and 8.2%, respectively. Representative samples of each ore were processed in air-lift percolators. A bioleaching experiment was performed in duplicate. The enrichment culture was obtained from the pyrite flotation wastes and used as an inoculum. Bioleaching was conducted for 60 days at ambient temperature (20-25°C). The recovery rates of gold from the bioleaching residues of Bakyrchik and Bolshevik ores by cyanidation were 21.0% and 48.5%, respectively. The results obtained in the present work may be used to estimate perspectives of heap bio-oxidation for the recovery of gold from these sulfide ores.
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Razmakhnin, KK, i PA Vasiljuk. "Technological and environmental features of heap leaching of Delmachik gold-bearing ores deposit". IOP Conference Series: Earth and Environmental Science 991, nr 1 (1.02.2022): 012044. http://dx.doi.org/10.1088/1755-1315/991/1/012044.
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Abstract The problem of gold ores hydrometallurgical processing with using sodium cyanide is evaluated. The prospects for the development of the use of cyanide-free reagents for leaching gold from ores are studied. The possibility of introducing a cyanide-free environmentally friendly reagent instead of the widely used sodium cyanide was determined. The results of experimental studies on the comparability of the processing of gold ores using sodium cyanide and a reagent based on sodium cyanoate are obtained. The optimal parameters of the technological process for the extraction of gold from ores using a cyanide-free reagent are established.
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Chen, Bo Wei, Jian Kang Wen i Guo Cheng Yao. "Acidophiles and its Use in Mineral Biomining with Emphasis on China". Advanced Materials Research 926-930 (maj 2014): 4201–4. http://dx.doi.org/10.4028/www.scientific.net/amr.926-930.4201.
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Acidophiles have been widely used in heap and dump bioleaching of secondary copper sulfide ores and biooxidation of refractory gold ores. 22 genera of acidophiles have been found in biomining environments. This paper gives a preliminary introduction to the application of mineral biomining in China. Challenges and technical trends for heap bioleaching of primary copper sulfide ores, purification of bioleaching solution of polymetallic sulfide ores and biooxidation of carbonaceous refractory gold ores are also recommended.
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Zalesov, M. V., V. A. Grigoreva, V. S. Trubilov i A. Ya Boduen. "Designing of engineering solutions to enhance efficiency of high-copper gold-bearing ore processing". Mining Industry Journal (Gornay Promishlennost), nr 5/2021 (12.11.2021): 51–56. http://dx.doi.org/10.30686/1609-9192-2021-5-51-56.
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The modern metals industry is characterised by a downward trend in the quality of ores involved in processing, and conventional methods of extracting useful components are inefficient for raw materials with complex composition. To maintain the growing level of metal production it is required to introduce new efficient technologies for processing of low-grade and refractory ores as well as man-made deposits. The article describes processing methods of refractory raw materials with high cyanide content using copper-gold ores as an example, where gold is the primary commodity, and copper is the accompanying useful component. The most common method of processing copper-gold ores is preconcentration followed by selective leaching of copper and gold. In some cases, technologies involving copper by-products and cyanide recovery from the cyanide leaching solutions offer equally effective options for processing of the copper-gold ores and concentrates. Copper-gold ores are processed at gold mines using the cyanide procedures, supplemented if required by gravity and flotation concentration. In all variations of the cyanide treatment, most of copper minerals actively react with cyanides of alkali metals, binding the CN– ions into the copper complex of [Cu(CN3)]2–. This reaction results in an increased solvent consumption, as well as in number of challenges related to cleaning tailings and slurries from highly toxic cyanide compounds and dissolved copper. In addition to technological complications associated with the need to meet strict requirements for the maximum permissible concentrations, copper accumulated in the cycling solutions also causes a decrease in gold extraction from the processed ores.
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Vikentyev, Ilya, Olga Vikent’eva, Eugenia Tyukova, Maximilian Nikolsky, Julia Ivanova, Nina Sidorova, Dmitry Tonkacheev i in. "Noble Metal Speciations in Hydrothermal Sulphides". Minerals 11, nr 5 (3.05.2021): 488. http://dx.doi.org/10.3390/min11050488.
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A significant part of the primary gold reserves in the world is contained in sulphide ores, many types of which are refractory in gold processing. The deposits of refractory sulphide ores will be the main potential source of gold production in the future. The refractory gold and silver in sulphide ores can be associated with micro- and nano-sized inclusions of Au and Ag minerals as well as isomorphous, adsorbed and other species of noble metals (NM) not thoroughly investigated. For gold and gold-bearing deposits of the Urals, distribution and forms of NM were studied in base metal sulphides by laser ablation-inductively coupled plasma mass spectrometry and by neutron activation analysis. Composition of arsenopyrite and As-pyrite, proper Au and Ag minerals were identified using electron probe microanalysis. The ratio of various forms of invisible gold—which includes nanoparticles and chemically bound gold—in sulphides is discussed. Observations were also performed on about 120 synthetic crystals of NM-doped sphalerite and greenockite. In VMS ores with increasing metamorphism, CAu and CAg in the major sulphides (sphalerite, chalcopyrite, pyrite) generally decrease. A portion of invisible gold also decreases —from ~65–85% to ~35–60% of the total Au. As a result of recrystallisation of ores, the invisible gold is enlarged and passes into the visible state as native gold, Au-Ag tellurides and sulphides. In the gold deposits of the Urals, the portion of invisible gold is usually <30% of the bulk Au.
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Andreev, Yury V. "Arsenic Precipitation from Solutions in Autoclave-Hydrometallurgical Technology of Processing Sulphide Concentrates". Solid State Phenomena 299 (styczeń 2020): 980–85. http://dx.doi.org/10.4028/www.scientific.net/ssp.299.980.
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Currently, the share of gold extracted from technologically simple gold ores is steadily decreasing, which determines the involvement in the processing of refractory gold ores containing finely disseminated gold and silver in sulfides, mainly in pyrites and arsenopyrites. Autoclave oxidation is a promising method of pretreatment of the refractory sulfide-arsenic gold-bearing raw materials before cyanidation. A serious problem of auriferous ores autoclave-hydrometallurgical processing is the removal of contained arsenic into relatively harmless and capable of being kept forms. This article shows the results of behavior of arsenic during the neutralization of solid after autoclave oxidative leaching of refractory gold-containing materials.
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Аskarova, G. Е., А. B. Begalinov, М. R. Shautenov i K. Аmantaiuly. "The main characteristics of the development of ores of the gold-bearing Vasilkovskoye deposit". Engineering Journal of Satbayev University 145, nr 3 (2023): 19–24. http://dx.doi.org/10.51301/ejsu.2023.i3.03.
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In the article, the continuous growth in the development of the gold mining industry in our country, the growth in the consumption of metals and other minerals justify the search for and development of new minerals, the development of new efficient technological schemes for mining. processing of minerals, development of new types of raw materials from difficult-to-enrich ores. Research is aimed not only at the preparation and development of new deposits, the determination of the enrichment of gold-bearing ores, but also at the theoretical development of methods for separating the components of mineral raw materials. There are more than 2.000 gold deposits in the Republic of Kazakhstan. Over the past two decades, studies of the structure of gold-bearing raw materials show an increasing trend in the extraction of ores. The continuous growth in the rate of development of the gold mining industry, the increase in the consumption of metals and other minerals justify the search for and development of new minerals, the development of new efficient technological schemes for the processing of minerals, the development of new types of raw materials from hard-to-enrich ores. Research is aimed not only at the preparation and development of new deposits, the determination of the enrichment of gold-bearing ores, but also at the theoretical development of methods for separating the components of mineral raw materials. In the last two or three decades, the proportion of gold obtained from technologically simple gold ores has been steadily declining. In nature, gold occurs mainly in the form of a native metal, intermetallic compounds and minerals containing gold, silver, copper, iron, mercury, bismuth, platinum, palladium, iridium, rhodium and gold gelluride minerals. In addition, gold occurs in the form of compounds with organic acids.
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Seitkan, A. S., i S. A. T. Redfren. "Arsenic in refractory gold ore processing". Kompleksnoe Ispolʹzovanie Mineralʹnogo syrʹâ/Complex Use of Mineral Resources/Mineraldik Shikisattardy Keshendi Paidalanu 317, nr 2 (15.06.2021): 5–13. http://dx.doi.org/10.31643/2021/6445.12.
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With "easy" ores becoming diminished, extractive industries are now shifting towards difficult deposits. In the future, gold-arsenic-bearing refractory ores will represent a prime example of the type of ores that may become more typical sourse for global gold recovery operations. Mining and beneficiation of As-bearing ores inevitably produce As-bearing wastes, which exacerbate any natural As mobilization. The mobility of As is governed by the interplay of redox reactions, adsorption/desorption, ion exchange, precipitation/dissolution, and biotransformation. The dominant processes depend on local biogeochemical conditions of the media, such as pH, Eh, chemical composition, as well as the presence and intensity of biological activity. This article provides an overview of current research on arsenic contamination of the environment caused by mineralization, mining and extraction of gold on the example of specific gold deposits.
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Umarov, Akromiddin, Anvar Shukurov, Alisher Djurabayev, Mansur Ruziev, Ilkhom Ruziev i Satbay Nurjanov. "Minerals of bismuth and antimony in original deposits of zarmitan gold zone, located in granitoid intrusion (Uzbekistan)". E3S Web of Conferences 401 (2023): 01002. http://dx.doi.org/10.1051/e3sconf/202340101002.
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Modern methods of nanomineralogy (electron microscopy, electron probe microanalysis) were used to study the ores of one of the largest industrial facilities of Uzbekistan - the Zarmitan gold zone, which includes the Zarmitan, Urtalik, Guzhumsay deposits, which are located in the Koshrabadgranosyenite massif. The development of / Au-W / Au-Bi-Te / Au-As / Au-Ag-Te / Au-Ag-Se / Au-Sb-Ag / Au-Hg / types of ores. Productive mineral-geochemical types of ores are Au-Bi-Te gold-bismuth-telluride, represented by maldonite, tellurides, and sulfosalts of bismuth: hedleyite, joseite, tsumite, tetradymite, matildite, treasure, and also Au-Sb-Ag gold-silver-sulfoantimonide type represented by aurostibite, sulfoantimonidesPb, Fe, Ag: plagionite, jamsonite, boulangerite, goodmundite, ovichiite and gold-pyrite-arsenopyrite with nanogold, lellingite, gersdorfite. The main industrial resource of gold is provided by Au-Bi-Te, Au-Sb-Ag, and partially Au-As types. The objects of the Zarmitan zone belong to the orogenic gold deposits associated with the intrusion. The established mineral and geochemical features of ores are direct signs of prospecting, typification, and assessment of hidden gold mineralization of orogenic belts.
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Mineev, Gennadiy, Andrey Vasiliev i Anton Nikitenko. "HEAP LEACHING OF GOLD ORES". Proceedings of Irkutsk State Technical University 21, nr 4 (kwiecień 2017): 147–56. http://dx.doi.org/10.21285/1814-3520-2017-4-147-156.
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Inculet, I. I., G. S. P. Castle, R. M. Quigley i K. J. Hodgson. "Electrostatic beneficiation of gold ores". IEEE Transactions on Industry Applications 24, nr 3 (1988): 380–86. http://dx.doi.org/10.1109/28.2885.
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Vassiliou, Andreas H. "Gold in Disseminated Carbonaceous Ores". JOM 40, nr 4 (kwiecień 1988): 26–28. http://dx.doi.org/10.1007/bf03259017.
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Hausen, D. M. "Processing Gold Quarry refractory ores". JOM 41, nr 4 (kwiecień 1989): 43–45. http://dx.doi.org/10.1007/bf03220200.
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Fraser, K. S., R. H. Walton i J. A. Wells. "Processing of refractory gold ores". Minerals Engineering 4, nr 7-11 (styczeń 1991): 1029–41. http://dx.doi.org/10.1016/0892-6875(91)90081-6.
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Medina, Diego, i Corby G. Anderson. "A Review of the Cyanidation Treatment of Copper-Gold Ores and Concentrates". Metals 10, nr 7 (5.07.2020): 897. http://dx.doi.org/10.3390/met10070897.
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Globally, copper, silver, and gold orebody grades have been dropping, and the mineralogy surrounding them has become more diversified and complex. The cyanidation process for gold production has remained dominant for over 130 years because of its selectivity and feasibility in the mining industry. For this reason, the industry has been adjusting its methods for the extraction of gold, by utilizing more efficient processes and technologies. Often, gold may be found in conjunction with copper and silver in ores and concentrates. Hence, the application of cyanide to these types of ores can present some difficulty, as the diversity of minerals found within these ores can cause the application of cyanidation to become more complicated. This paper outlines the practices, processes, and reagents proposed for the effective treatment of these ores. The primary purpose of this review paper is to present the hydrometallurgical processes that currently exist in the mining industry for the treatment of silver, copper, and gold ores, as well as concentrate treatments. In addition, this paper aims to present the most important challenges that the industry currently faces, so that future processes that are both more efficient and feasible may be established.
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Askarova, Gulzhan, Mels Shautenov i Kulzhamal Nogaeva. "Flotation enrichment of resistant gold ores". E3S Web of Conferences 168 (2020): 00005. http://dx.doi.org/10.1051/e3sconf/202016800005.
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Ores of the Vasilkovsky deposit include arsenopyrite, pyrite, pyrrhotite, marcasite, gold, chalcopyrite, sphalerite, galena, faded ore (tennantite)S, bismuthine, native bismuth, lellingite, molybdenite, cubanite, bornite, antimonite, relict minerals, magnetite, apatite and apatite chromite, sericite, chlorite, potassium feldspar, tourmaline), quartz, carbonates (siderite, ankerite, calcite), fluorite, barite. Arsenopyrite is the main ore mineral. It contains the bulk of gold, as well as impurities - copper, cobalt, nickel, bismuth, zirconium, titanium, lead, zinc, antimony, silver, molybdenum. Bismuth and its minerals are widespread, they are constantly associated with arsenopyrite, forming intergrowths with native gold, less often with chalcopyrite and faded ore. Native gold is distributed very unevenly, forms the finest precipitates ranging in size from tenths of a micron to 0.063 mm, grows together with quartz, arsenopyrite, pyrite and bismuth minerals. Rich ores were formed by combining bismuthcontaining associations with arsenopyrite. The role of gold in arsenopyrite increases with depth. Ores are of the gold-quartz-sulfide type. Quartz in ore up to 90 %, sulfides from 3 to 5 %. The content of harmful impurities (arsenic) reaches 2 % or more. Ores are refractory, require special technology for the beneficiation and extraction of gold.
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Osmonbetov, E. "Geology and Goldness Deposits Shambesai". Bulletin of Science and Practice 6, nr 5 (15.05.2020): 249–56. http://dx.doi.org/10.33619/2414-2948/54/31.
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The specificity of the location and the degree of field search are shown. The characteristic of ore zones (bodies), the mineral composition of ores and reserves are given. The deposit is similar to the gold deposits of the Karlinsky type. Two main technological types of ores have been distinguished: easily miscible oxidized ores that do not contain harmful impurities, suitable for heap leaching, and refractory sulfide gold-arsenic ores, requiring special complex processing methods. These ores are planned to be mined together with oxidized and temporarily stored separately. It is necessary to organize a public hearing and involve professional experts in the examination of projects.
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Stepanov, Vitali. "On the gold content in the antimony and mercury mineralization in Priamurye". Ores and metals, nr 1 (7.04.2023): 40–51. http://dx.doi.org/10.47765/0869-5997-2023-10004.
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The data on the geological and structural position, composition of metasomatites, ores, and gold content of antimony and mercury deposits and occurrences of the Priamursky gold-bearing area are presented. It was established that the ores of many of them contain native gold, whose concentration reaches commercial values. Some of the gold-bearing antimony and mercury deposits serve as sources of the formation of gold placers. By the composition of ores, near-ore metasomatites and samples of native gold, the analogues of these deposits and occurrences are the famous gold deposits of Yakutia - Sarylakh of the gold-antimony formation and Kyuchus of the gold-mercury formation. It is recommended to audit a number of mercury and antimony deposits and occurrences in the Priamursky province for gold. As a result, it is expected to identify deposits of gold-antimony and gold-and-mercury formation. In addition, occurrences of antimony and mercury may be indicative of the presence of gold-sulfide formation deposits in the bedrock, similar to a large deposit Mayskoye (Chukotka).
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Olson, Gregory J. "Microbial oxidation of gold ores and gold bioleaching". FEMS Microbiology Letters 119, nr 1-2 (czerwiec 1994): 1–6. http://dx.doi.org/10.1111/j.1574-6968.1994.tb06858.x.
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Abramov, B. N. "KARA GOLD ORE CLUSTER (EASTERN TRANSBAIKALIA): GEOCHEMICAL FEATURES OF ORES, THE RELATIONSHIP OF MAGMATISM WITH MINERALIZATION". Geology and mineral resources of Siberia, nr 1 (2023): 61–67. http://dx.doi.org/10.20403/2078-0575-2023-1-61-67.
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Dykes of the Amudzhikano-Sretenskiy complex (J3–K1) including hybrid porphyries are widely developed in the area of the Kara gold ore cluster. The parameters of the lanthanides distribution in them are close to those of ores of the quartz-tourmaline-pyrite association, indicating probable single sources of their formation. In hybrid porphyries, ΣTR is 52.24–123.35; in ores of the quartz-tourmaline-pyrite association ΣTR is 52.82–133.78. In hybrid porphyries, Eu/Sm is 0.18–0.65; in ores of the quartz-tourmaline-pyrite association Eu/Sm is 0.18–0.47. The degree of differentiation of magmatic chambers according to Eu/Eu* is 0.61-2.26 in dikes of hybrid porphyries; Eu/Eu* is 0.78–1.49 in ores of quartz-tourmaline-pyrite association. The represented data indicate that their magmatic chambers of dikes of hybrid porphyries and quartz-tourmaline-pyrite ores were not differentiated and, consequently, had a deep source. According to the geochemical composition, part of the Amudzhikano-Sretenskiy complex granite values corresponds to ore-bearing granites with goldmolybdenum mineralization. Ores of the actinolite-magnetite association are characterized by the highest gold contents among productive stages of gold mineralization. Close correlation relationships of Au with Zn, W, Mo were established in ores of the actinolite-magnetite association; in ores of the quartz-tourmaline-pyrite association – with Mo, Pb; in ores of the quartz-arsenopyrite association – with Pb, Mo, As, Ag.
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Munganyinka, Jeanne Pauline, Jean Baptiste Habinshuti, Jean Claude Ndayishimiye, Levie Mweene, Grace Ofori-Sarpong, Brajendra Mishra, Adelana R. Adetunji i Himanshu Tanvar. "Potential Uses of Artisanal Gold Mine Tailings, with an Emphasis on the Role of Centrifugal Separation Technique". Sustainability 14, nr 13 (3.07.2022): 8130. http://dx.doi.org/10.3390/su14138130.
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Few investigations have focused on the potential uses of artisanal gold (Au) mine tailings, despite the fact that artisanal gold mining activity contributes to environmental issues such as greenhouse gas. Mineralogical characterizations of artisanal gold mine tailings in Miyove gold mine (Baradega and Masogwe) in Rwanda were investigated for potential utilization as a source of valuable gold, using the centrifugal separation technique. Results of X-ray diffraction analysis, energy dispersive X-ray spectroscopy, inductively coupled plasma mass spectrometry, inductively coupled plasma–optical emission spectroscopy, and X-ray fluorescence showed that artisanal gold mine tailings samples have significant amounts of gold to justify economical gold extraction opportunity. The gold grades in the ores and artisanal gold mine tailings were in the ranges of 37–152 and 2–7 g t−1, respectively. Quartz was a major phase, with minor impurities in two different types of gold ores and their respective tailings. The beneficiation carried out using centrifugal separation, regarded as an extension of gravity separation, showed gold grades in the range of 535–1515 g t−1 for gold ores and 36–302 g t−1 for artisanal gold mine tailings. The gold recoveries for ores and artisanal gold mine tailings were in the range of 21.8–47.3% and 46.9–63.8%, respectively. The results showed that the centrifugal separation technique was more efficient in boosting gold recovery compared to the present panning approach employed at the site, which sometimes recover as low as 10%. The results suggest that mineralogical characterization of artisanal gold mine tailings allows for the development and design of a suitable methods for improving gold ore beneficiation and artisanal gold mine tailings reprocessing.
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SANAKULOV, Kuvondik, Alexander VOROBYOV, Evgeny KOZYREV i Zhang LIANZI. "Physical and chemical properties of gold nanoparticles in ores and catalysts". Sustainable Development of Mountain Territories 14, nr 4 (30.12.2022): 676–84. http://dx.doi.org/10.21177/1998-4502-2022-14-4-676-684.
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Introduction. At present, in the instrumental study of the mineral forms of finding gold in geogenic and technogenic ores, more and more attention has been paid to free gold, with a size of several nanometers. Such gold has been found in almost all types of its geogenic ores: starting with deposits of primary sulfide ores and ending with various gold-bearing placers. A similar situation is observed with technogenic gold-bearing ores accumulated in numerous dumps and tailings. At the same time, with the increase in research on nanogold, not only its fundamental, but also practical importance grows, because. in theoretical and applied research, more and more of its actual physical and chemical properties and previously unknown phenomena and effects accompanying them are discovered and clarified. Research methods and materials. An important aspect is the instrumental study of the geometry of various forms of nanogold occurrence in natural (geogenic) and technogenic ores and minerals. The instrumental and analytical part of our research was based on the visualization of nanoparticles obtained from the Nanjing Research Institute of the Chemical Industry under Sinopec (PRC), carried out on a JEOL 2010F microscope. Research results. The studied gold nanoparticles were presented in the form: • spherical fullerene-like monoparticles; • fullerene-like gold cells, consisting of a different number (from 13 to 20 clusters) of gold nanoparticles; • self-organized «fractal» dendrites; • rather complex composites with the participation of nanogold; • various aggregates of nanoparticles, etc. The concentrations of gold nanoparticles vary significantly from one deposit to another and between individual ore facies (even within the same deposit). Discussion of the obtained results. It was found that nanogold can be contained in arsenopyrites in 2 main forms: a) as a structurally bound solid solution (Au + 1) located in the lattice of this mineral; b) in separate mineral inclusions of submicron size or nanoparticles. Gold nanoparticles (5-10 nm in size) detected in arsenopyrite in concentrations up to 4% mass fraction are sufficiently representative to account for their amount in gold-bearing ores. A gold nanoparticle with a size of 3 nm usually has an average coordination number CN = 9.5, similar nanoparticles with a size of 1 nm have an average CN = 6, and nanoparticles with a size of 0.5–1 nm have an average CN = 3.6. Conclusion. To date, a nanoparticle catalyst has been developed in which gold clusters are attached to metal oxides that are semiconductors. At the same time, their number is very limited and includes only Fe2O3, TiO2, CeO2, and MgO compounds, which can be used not only in the form of nanoparticles, but also nanofilms. Such an innovative nanocatalyst ensures the efficient flow of a number of oxidative and other processes with hydrocarbons at normal temperatures, which is difficult to achieve by other methods. Findings. The article presents the results of studies of the physicochemical properties of gold nanoparticles installed in ores and catalysts. The morphology of gold nanoparticles has been established. The character of gold speciation in various sulfides is determined. The presence of gold nanoparticles in ores and rocks in the state of colloids has been confirmed. The catalytic activity of nanoparticles of various shapes and chemical states was revealed, depending on the values of the ambient temperature. The results of the research can be useful in the enrichment of gold-bearing ores of upland deposits.
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Shang, He, Jian Kang Wen i Biao Wu. "Biooxidation of High-Sulfur Refractory Gold Concentrate by Ferroplasma acidiphilum". Advanced Materials Research 997 (sierpień 2014): 642–45. http://dx.doi.org/10.4028/www.scientific.net/amr.997.642.
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Gold ores can be categorized into two types-free milling and refractory. Free milling ores are easy to treat. Gold in such ores is recovered by gravity separating techniques or direct cyanidation. Refractory gold ores, on the contrary, are difficult to treat and require pre-treatment prior to cyanidation, such as roasting, pressure oxidation, fine grinding and biooxidation. A number of bacteria are used in biomining but the prominent ones that are known to be involved in the oxidation of sulfide ores include Thiobacillusferrooxidans, Thiobacillus thiooxidans and Leptospirillum ferrooxidans. In this study, the gold concentrate was biooxidized in a reactor at 45°C over a period of 10 days at a pulp density of 15% solids using a culture of already grown Ferroplasma acidiphilum. The initial pH was adjusted to 1.5 with sulfuric acid, resulted in 85.39 % oxidation of sulfur from initial grade of 33.83 %, and the slag rate was 68.52 %. The products of sulfide biooxidation were leached at a pulp density of 20 %(v/w) for 24 h at pH 11. The pH was adjusted using CaO and cyanide strength was 10 kg/t, we got a gold extraction of 90.71 %, which ncreaseed 80.09 % compared with the direct cyanide leaching.
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MYKHAILOV, Volodymyr, Ivan VIRSHYLO, Vasyl ZAGNITKO, Dmytro KRAVCHENKO, Oleksandr DUBYNA, Vitaliy SUKACH i Sergii CHULKOV. "TIJIRIT GOLD ORES DISTRICT IN MAURITANIA". Visnyk of Taras Shevchenko National University of Kyiv. Geology, nr 4 (103) (2023): 66–73. http://dx.doi.org/10.17721/1728-2713.103.08.
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The distribution of a new gold ore district in the Republic of Mauritania – Tijirit, which is associated with the greenstone belt (GSB) of Sebkhet Nich of submeridional extension, is substantiated. It is located 25–30 km to the east of the Reguibat GSB, where the large Tasiast gold deposit is known. The coincidence of the structural position of these two objects and direct signs of gold ore mineralization in the territory of the Tijirit ore district in the form of contrasting lithochemical anomalies of gold, grab sample and trench sample with an increased gold content make it possible to highly evaluate the prospects of its gold ore mineralization. In the ore district, four submeridional to north-northeast trending ore-bearing zones have been identified, within which a number of gold occurrences have been established: Sophie-I, II, III, Lily, Eleonore, Eleonore East, Salma. They coincide with the weakened zones of the same direction, as a rule, they are confined to the contacts of rocks of different composition (metabasalts, metasandstones, banded iron formations, granites), stand out on space image, in geophysical fields, and control the placement of mineralization zones. Of these zones, the most interesting for further geological exploration works is the relatively poorly studied Eastern mineralization zone, which is confined to the contact of the Salma granites and the metabasites of the eastern wing of the Sebkhet Nich GSB. It is associated with the Eleonore East and Salma gold occurrences, numerous lithochemical anomalies, grab, trench and core samples with increased gold content (up to 42–100 g/t). It is recommended to concentrate further geological exploration work within this zone. A number of gold deposits in Ukraine (Sergiivske, Balka Shiroka, Balka Zolota, Surozke) are also associated with the Mesoarchean greenstone structures of the Ukrainian Shield. We hope that the experience of studying gold ore objects in West Africa will help to conduct an objective assessment of gold ore objects in Ukraine.
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Yongkang, Liu, Liu Shirong, Wan Guangquan, Zhou Lindi, Li Jilian i Lu Fangqiong. "A Study on the Occurrence of Gold in Unoxidized Carlin-Type Ores in China Using AEM, SEM-EDX and SXRF". Proceedings, annual meeting, Electron Microscopy Society of America 48, nr 2 (12.08.1990): 414–15. http://dx.doi.org/10.1017/s0424820100135678.
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The knowledge about the occurrence of gold is essential both to the explanation for the genesis of gold mineralization in its deposits and to the evaluation and exploration or even smelt process of its ores. It has been well known that the gold occurrence in the Carlin-type ores still remains a difficult question to be answered because of the tiny scale of its locality and its very low content.This paper reports the results of our analysis on some gold bearing minerals in the Carlin-type ores discovered during recent years in China with combined use of analytical electron microscopy (AEM), scanning electron microscopy-energy dispersive X ray spectrometry (SEM-EDX) and synchrotron X ray flourescence analysis (SXRF) techniques as following:(1) Some gold occurred as submicron size grains in the ores (see Photo 1-4 and Figure 1-3) with grain size generally less than 0.2 micron.(2) It has been found by AEM and SEM-EDX observation and SXRF analysis that gold occurred as micrograins embedded in the boundaries of clay or quartz minerals rather than, as said, entered the lattice or adhered as a covering film to the surface of clay minerals (see Figure 4).
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Jiang, Mei Guang, Quan Jun Liu, Jun Long Yang i Hong Xiao. "The Method for the Characterization of Carlin Trend Gold Ores". Applied Mechanics and Materials 295-298 (luty 2013): 3071–74. http://dx.doi.org/10.4028/www.scientific.net/amm.295-298.3071.
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Carlin Trend gold ores are often refractory by conventional cyanid, for a number reasons:1) the gold is locked up within host sulfide minerals such as pyrite or arsenopyrite; 2) the ore contains carbonaceous compounds which are preg-robbing; 3) the gold is locked up in silicate minerals. An alternative technique called diagnostic leaching, originally developed by the Anglo American Research Laboratories in South Africa, has been used successfully to distinguish between a wide variety of different gold associations, including the proportion of preg-robbing gold in carbonaceous gold ores.
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De la Nuez Colon, D., i M. Santa Cruz Pacheco. "Gold and gold-bearing volcanogenic massive sulphide deposits of the Central Cuba". Proceedings of higher educational establishments. Geology and Exploration, nr 3 (28.02.2021): 27–37. http://dx.doi.org/10.32454/0016-7762-2020-63-3-27-37.
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Background. Volcanogenic massive sulphide deposits (VMS) are the most important sources of Cu and Zn; they account for a large share of the world production of Pb, Ag, Au, Se, Te, Bi and Sb, as well as small amounts of many other metals. The polymetallic VMS deposits of economic value of varying degrees are known in the rocks of the Los Pasos Cretaceous Formation, Cuba.Aim. To show the potential of the Cretaceous volcanic deposits of Central Cuba for gold, silver, copper, zinc and lead deposit prospecting.Materials and methods. The study characterises the San Fernando, Independencia, Antonio, Los Cerros VMS deposits and the Boca del Toro and El Sol ore occurrences located in the Los Pasos Formation. The similarities and differences in the mineral and elemental composition and structures of the ores of these objects are described, which underlie the assessment of their economic importance.Results. The latitudinal zoning of VMS and noble metal mineralisation of the Central Cuban ore region is outlined. In the west, copper-VMS deposits with accompanying gold ore objects prevail. In the east, copper-zinc VMS deposits with barite and gold-silver objects are widespread.Conclusions. It is necessary to assume the different erosional sections corresponding to the blocks of the Cretaceous volcanic arc of Central Cuba, which is larger in the west and smaller in the east. Proceeding from the presence of veinlet gold ores, their confinement to tectonic zones and the lack of correlation between noble and chalcophile metals at the San Fernando deposit, as well as significantly different gold-silver ratios in the considered ore objects, it could be assumed that some of the gold-silver ores were formed after VMS. The obtained Au/Ag ratios are close to the ores of the high sulphidation type (high sulphide ores) from similar ore regions of Venezuela and the Kur-il island arc. In this regard, one can expect hidden gold deposits in the west and gold-silver deposits in the east of the studied area.
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Sayitov, Sardor S., i Vladimir D. Tsoi. "MINERALOGICAL AND GEOCHEMICAL FEATURES AND PROSPECTS FOR COMPLEX MINERALIZATION OF THE YAKHTON DEPOSIT (MOUNTAINS CHAKYL-KALYAN, UZBEKISTAN)". Bulletin of the Tomsk Polytechnic University Geo Assets Engineering 334, nr 9 (29.09.2023): 76–90. http://dx.doi.org/10.18799/24131830/2023/9/4107.
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Link for citation: Sayitov S.S., Tsoi V.D. Mineralogical and geochemical features and prospects for complex mineralization of the Yakhton deposit (mountains Chakyl-Kalyan, Uzbekistan). Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 9, рр. 76-90. In Rus. The relevance. The results of mineralogical and geochemical studies increase the efficiency of exploration work, since reliable knowledge about the distribution of useful components and their finding forms in various types of ores, character of distribution, their intergrowth, sequence of hypogene mineral formation are necessary for predicting the ore potential of objects and determining the directions of geological exploration. In addition, the data of mineralogical and geochemical studies are used in the development of a rational scheme for the enrichment of ores and ensure the complex processing and use of mineral resources. The main aim of the research is to study the material composition and mineralogical and geochemical features of ores and ore-bearing rocks. Object of the research is Yakhton deposit, located in the Chakyl-Kalyan mountains of Uzbekistan, which is known as a skarn tungsten object with associated gold. The results of recent exploration work have shown high prospects of the object for gold mineralization. Industrial grades of gold with a complex of associated components were established in the zones of metasomatic alteration of granitoids. Methods. Chemical composition of ores was studied by silicate, spectral semi-quantitative, ICP-mass spectrometric, atomic absorption, chemical research methods. Mineral composition of ores was established by complex analyzes: optical microscopy in transmitted and reflected light, mineralogical analysis of heavy fractions, X-ray spectral local analysis under a microprobe. Results. Ore and ore-bearing rocks of Yakhton deposit are aluminosilicate (granitoid) and carbonate (skarns, limestones) composition. The ores of the Yakhton deposit are complex. The content of gold in the composition of ores is up to 4,45 g/t, tungsten oxide is up to 0,33 %. In the sequence of increasing concentration clarks in the composition of ores, the following series of elements with clarke concentrations of 40–16500 times was established: Sb<W<Re<Au<Cu<As<Ag<Se<Mo<Te<Bi. The mineral form of gold is native gold, electrum. The pyrite-arsenopyrite paragenetic mineral association is the main productive one for gold mineralization. The manifestation of the gold-silver stage and the telescoping of several paragenetic mineral association are due to the formation of complex ores.
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Mhandu, Takunda Joseph, Ilhwan Park, Sanghee Jeon, Sohta Hamatsu, Yogarajah Elakneswaran, Mayumi Ito i Naoki Hiroyoshi. "A Pretreatment of Refractory Gold Ores Containing Sulfide Minerals to Improve Gold Leaching by Ammonium Thiosulfate: A Model Experiment Using Gold Powder and Arsenic-Bearing Sulfide Minerals". Metals 13, nr 8 (28.07.2023): 1357. http://dx.doi.org/10.3390/met13081357.
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The use of thiosulfate to extract gold from refractory ores is promising because of its non-toxicity and high selectivity. Sulfide minerals (i.e., pyrite, arsenopyrite, chalcopyrite), major gold carriers in refractory gold ores, however, hinder gold extraction due to the high consumption of a lixiviant. In this study, a new method to improve gold extraction from sulfide bearing gold ores is proposed based on the model experiments using a mixture of gold powder and arsenopyrite-bearing sulfide (HAsBS) ore. The effects of HAsBS ore on gold leaching in ammonium thiosulfate solutions were investigated, and it was found that gold extraction in the presence of HAsBS ore was suppressed because of the unwanted decomposition of thiosulfate on the surface of sulfide minerals. To improve gold extraction in the presence of the sulfide minerals, this study investigated the effects of the pretreatment of HAsBS ore using ammonium solutions containing cupric ions and confirmed that HAsBS ore was oxidized in the pretreatment and its surface was covered by the oxidation products. As a result, thiosulfate consumption was minimized in the subsequent gold leaching step using ammonium thiosulfate, resulting in an improvement in gold extraction from 10% to 79%.
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Silyanov, Sergey A., Anatoly M. Sazonov, Yelena A. Zvyagina, Andrey A. Savichev i Boris M. Lobastov. "Gold in the Oxidized Ores of the Olympiada Deposit (Eastern Siberia, Russia)". Minerals 11, nr 2 (11.02.2021): 190. http://dx.doi.org/10.3390/min11020190.
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Native gold and its satellite minerals were studied throughout the 300 m section of oxidized ores of the Olympiada deposit (Eastern Siberia, Russia). Three zones are identified in the studied section: Upper Zone ~60 g/t Au; Middle Zone ~3 g/t Au; Lower Zone ~20 g/t Au. Supergene and hypogene native gold have been found in these zones. Supergene gold crystals (~1 μm), their aggregates and their globules (100 nm to 1 μm) predominate in the Upper and less in Middle Zone. Relic hypogene gold particles (flattened, fracture and irregular morphology) are sporadically distributed throughout the section. Spongiform gold occurs in the Lower Zone at the boundary with the bedrock, as well as in the bedrock. This gold formed in the process of oxidation of aurostibite, leaching of impurities and its further dissolution. Hypogene gold is commonly isolated but for supergene gold typically associated with ferric (hydr)oxides. New formation of gold occurred due to oxidation of sulfide ores and release of “invisible” gold, as well as dissolution, mobilization and re-deposition of metallic hypogene gold. A model for the formation of oxidized ores with the participation of meteoric and low-temperature hydrothermal waters has been proposed.
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Zvereva, N., V. Myazin i I. Kostromina. "Technological possibility of increasing the complexity of the use of gold-bearing polymetallic ores of the Novo-Shirokinsky deposit". TRANSBAIKAL STATE UNIVERSITY JOURNAL 28, nr 6 (2022): 6–14. http://dx.doi.org/10.21209/2227-9245-2022-28-6-6-14.
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Gold-bearing polymetallic ores of the Novo-Shirokinsky deposit (further NShD) are complex, containing other valuable components besides gold and silver, which include lead, zinc, copper, iron, etc. According to the content of sulfides in the ores, they belong to the moderate sulfide type. The main feature of the material composition of ores NShD: expressed multicomponent content of valuable minerals; proximity of flotation properties of shared minerals; especially valuable mineral in ores, in addition to gold and silver, is copper, which is mainly concentrated in lead concentrate. The highest technological indicators of ore beneficiation are achieved when they are enriched according to a collective technological scheme. The technological scheme of ore beneficiation at the plant is shown in fig. 1. A lead-copper concentrate is obtained, which, as a rule, is subsequently sent for subsequent selective flotation. The factory produces two main concentrates - lead and zinc (corresponding to TU 07.29.15-002-24722376-2018, TU 1725-001-24722376-2011). This work is aimed at increasing the complexity of the use of NShD polymetallic ores in order to justify the possibility of additional production of copper concentrate at the plant. The object of the study – gold-bearing polymetallic ores of the Novo-Shirokinsky deposit. The subject of the study – flotation process of ore beneficiation as the basis for obtaining copper concentrate by constructing effective technological schemes for the polymetallic ores’ processing. The main idea of the work – sequential extraction of copper from lead concentrates using retreatments and optimal operating parameters of the flotation process
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Belogub, E. V., K. A. Novoselov, I. B. Fadina i M. A. Rassomakhin. "Alteration of sulfide ore of the Samolazovskoe deposit, Aldan shield, in an experimental bioleaching heap". МИНЕРАЛОГИЯ (MINERALOGY) 9 (29.03.2023): 45–59. http://dx.doi.org/10.35597/2313-545x-2023-9-1-3.
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The article contains the results of a mineralogical study of sulfide ores of the Samolazovskoe deposit (Aldan Shield) and the products of their experimental bacterial oxidation in a heap. Pyrite and marcasite are the major minerals of primary ores. They form fine-grained crystalline and micrometer-grained to cryptocrystalline aggregates. Sphalerite, galena, chalcopyrite, pyrrhotite, fahlore, luzonite, bournonite and other Sb sulfosalts, antimonite, arsenopyrite are minor minerals. Tiemannite, coloradoite, calaverite, hessite, petzite and native gold are rare. The ores in the experimental biooxidation heap are mostly altered in its upper parts. The secondary products of the alteration of ores include fine-grained Mg- and S-bearing calcite, smectites after feldspars, and films of Fe3+oxyhydroxides on the surface and in fractures of ore. In the lower part of the heap, technogenic processes are weak and mainly include the formation of gypsum . The sulfides are preserved throughout the heap vertical profile including very fine crystalline, colloform and botryoidal aggregates with a nonstoichiometric ratio of cations and anions and the presence of As, Ni and Cu. The botryoidal aggregates of the Fe disulfides contain galena, which forms a “microseptary” structure, which was not found in primary ores. The high-fineness native gold was found in assemblage with coloradoite and calaverite as inclusions in fine-grained aggregates of Fe disulfides. The conclusion is made on an insufficient impact of the bioleaching of refractory ores in the irrigation regime used, and forming of the secondary minerals that prevent the extraction of gold. Keywords: Samolazovskoe deposit, Aldan Shield, coloradoite, calaverite, native gold, refractory ores, bio-oxidation.
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Christova, Julia, Todor Todorov i Kalinka Petrova. "Distribution of the silver in Bulgaria ore deposits". Geologica Balcanica 33, nr 1-2 (30.06.2003): 3–16. http://dx.doi.org/10.52321/geolbalc.33.1-2.3.
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The content of silver in the different, in terms of genesis and macrochemism, endogenic mineralisations in Bulgaria varies from 1-2 to 200 g/t, most frequently 5-35 g/t. The highest concentrations of this element are registered in the West Balkan region (lead-silver ores near Chiprovtsi, gold-sulphide ores near Govezhda and polymetallic ores Iskar-Vratsa ore region as well as Kremikovtsi deposit); in the Central Rhodopes region (lead-zinc deposits in Laki, Madan and Davidkovo ore fields, Ardino silver-polymetallic deposit); in the lead-zinc ores in Ossogovo ore region; in the East Rhodopes ore region (gold-silver-polymetallic ores in Madzharovo ore field and Popsko, silver-gold ores in Sedefche and Sarnak); in the East Srednogorie (gold-copper-polymetallic ores near Bakadzhik and Zidarovo). Some of the more significant favourable geological prerequisites for the accumulation of silver in the ores are: Late Paleozoic or Tertiary (Oligocene-Miocene) age, geodynamic environments of collision and zones with thick earth crust, anticlinoria and big horst-like uplifts, WNW and NW host structures, close to the surface or flange sections of the mineralisations. The mineralisations with higher content of silver are, as a rule, related to granites. Their host rocks are carbonates with development of metasomatic processes such as dolomitisation and granitoids with periore alterations of the quartz-sericite, quartz-mica (beresite), adular-sericite or quartz-adularia metasomatites and argillizites. The composition of the ores includes lithophile-chalcophile geochemical associations with prevalence of antimony. A favourable factor for the accumulation of silver is the lead-zinc macrochemism with prevalence of lead in zones with thick earth crust and the polymetallic - in zones with basificated (subocean type) earth crust. The mineral composition of the ores includes galena, sulphosalt silver minerals, the especially high silver-bearing tetrahedrite-tennantite series with prevalence of tetrahedrite and participation of magnesium and iron carbonates (siderite, ankerite, dolomite). The character of the silver-bearing mineralisations in Bulgaria is medium to low-temperature and, according to their peculiarities, they can be related to the mesothermal, epithermal or telethermal genetic classes.
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VALIEV, NIYAZ, GAMET HUSEYNOV i ZARIFA EFENDIYEVA. "SOME TYPOMORPHOUS FEATURES OF NATIVE GOLD OF THE DAGKESAMAN POLYMETALLIC PYRITE DEPOSIT AND THEIR PRACTICAL SIGNIFICANCE". News of the Tula state university. Sciences of Earth 1, nr 1 (2023): 348–59. http://dx.doi.org/10.46689/2218-5194-2023-1-1-348-359.
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The typomorphic features of native gold are considered, which provide valuable information in the study of the conditions for the formation of ores. When determining the stages and stages of ore deposition at the Dagkesaman deposit, data on the forms of isolation, chemical composition and internal structure of gold particles were used. The established granulometric composition and mineral association of gold are ofpractical importance in the technological processing of ores.
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Grigoreva, V. A., i A. Ya Boduen. "Prospects for refractory gold-sulfide ore processing". Izvestiya. Non-Ferrous Metallurgy, nr 6 (4.01.2024): 22–34. http://dx.doi.org/10.17073/0021-3438-2023-6-22-34.
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Cyanide-refractory ores constitute 30 % of the world’s gold mineral resource base. With the global decrease in the availability of high-grade and free-milling ores, low-quality ores, including those rich in sulfur and arsenic, are increasingly being processed. The authors have conducted an assessment of the primary factors complicating the leaching process of refractory gold. These factors include the influence of gold distribution within the ore, the presence of preg-robbing effects, and the impact of cyanicidal minerals, notably pyrrhotite, on the leaching process. Sulfide minerals significantly affect the kinetics of gold leaching and associated reagent costs. The behavior of Fe5S6 is elucidated through the concept of “chemical depression”. Under cyanide leaching conditions, pyrrhotite actively and directly reacts with NaCN/KCN, undergoing surface oxidation by dissolved oxygen in the pulp. This leads to the formation of ferrocyanide complexes and rhodanides, which are unable to leach gold. Presently, there are two approaches to enhance the process parameters of refractory ore processing technology. The first approach involves the inclusion of preparation operations for cyanidation, aimed at liberating gold from the sulfide matrix (including hydrometallurgical and pyrometallurgical oxidation technologies and mechanical activation). An alternative approach is to use alternative reagents as leaching agents (notably thiourea, sodium and ammonium thiosulfates, and halides). The article explores means of modifying the technological process for gold extraction when ores contain substantial amounts of pyrrhotite or concentrates.
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Radomskii, S. M., i V. I. Radomskaya. "Features of noble metals at Pioneer gold deposit". Earth sciences and subsoil use 45, nr 1 (31.03.2022): 50–59. http://dx.doi.org/10.21285/2686-9993-2022-45-1-50-59.
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The purpose of the present study is to evaluate the mass fractions of the group of noble metals (gold, silver, platinum, ruthenium, osmium, palladium, iridium, rhodium) in the ores and host rocks of the Pioneer deposit (the Upper Amur Region, Russia) and to determine their migration activity and hydrochemical classification of ore metals by sizes. The object of the study is primary and oxidized ores, as well as rocks hosting this mineralization. The study employs the method of quantitative chemical analysis, micro assay melting with an error of correctness, accuracy and reproducibility of the results of ≤30 %. Pioneer is a near surface hydrothermal deposit with oxidized and sulfide types of ores, which are processed both by the open method of alkaline heap cyanide leaching, and by the closed pressure method, respectively. A gold concentration plant was built to implement these processing methods. The main recoverable component of this technology is gold, whereas silver and platinum group metals are present in industrial products as impurities. The technology is highly profitable, which allows cost-effective processing of ores with the mass fractions of 1–4 ppm of gold. The performed hydrochemical classification of the sizes of native gold minerals has showed that the bulk of the nuggets (74– 78 %) of primary, sulfide, and oxidized ores accounts for the fraction with the sizes of 160–1000 μm and 11–13 % account for the fraction with sizes of 16–40 μm. Fine gold of the deposit provides its complete dissolution during the cyanidation process.
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FEDOTOV, Pavel, Arkadiy SENCHENKO, Konstantin FEDOTOV i Aleksander BURDONOV. "Studies of enrichment of sulfide and oxidized ores of gold deposits of the Aldan shield". Journal of Mining Institute 242 (25.05.2020): 218. http://dx.doi.org/10.31897/pmi.2020.2.218.
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The paper presents the analysis of studies of the enrichment of sulfide and oxidized ores in Yakutia deposits. The ore of the deposit is a mixture of primary, mixed and oxidized ores. The main useful component of the studied ore samples is gold with a content of 1.5 to 2.8 g/t, the silver content is low – 5-17 g/t. Ore minerals are represented by sulfides, among which pyrite predominates. The total sulfide content does not exceed 3-5 %. The presence in the ore of free and associated gold with a grain size from fractions of a micron to 1.5 mm. Gold is represented by nuggets in intergrowth with sulfides and also forms independent inclusions. Ores are classified as easily cyanidable.
It was found that the content of amalgamable gold is 10-49, the share of cyanidable gold ranges from 66.67-91, the share of refractory gold is 9.0-33.33 %, which in absolute amount equals to 0.24-0.8 g/t. The extraction of gold in gravitation concentrate varies depending on the gold content in the ore and the yield of concentrate and for ores with a gold content of 1.5-2.8 g/t from 40 to 60 %. The direct cyanidation of all studied ore samples established the possibility of extracting gold into solution up to 86.7-92.9 %, the gold content in cyanidation cakes is 0.2-0.3 g/t. Investigations of the gravitation concentrate by the method of intensive cyanidation showed that with an initial gold content of ~ 500 g/t, up to 98.9 % is extracted into the solution. The gold content in intensive cyanide cakes will be 6-15 g/t. A set of studies carried out by the authors of the article at various institutes showed that it is advisable to process ore from the deposit using cyanidation technology with preliminary gravitational extraction of gold.
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Rubtsov, Yu, А. Trubachev, E. Voronov, A. Lavrov i A. Lavrik. "INTENSIFICATION OF DISPERSED AND FINE-GRAINED SILVER EXTRACTION IN CYANIDE HEAP LEACHING OF GOLD". Transbaikal State University Journal 26, nr 8 (2020): 40–48. http://dx.doi.org/10.21209/2227-9245-2020-26-8-40-48.
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Since the cost of gold has increased by an order of magnitude over the past 20 years, gold mining began to be carried out from ores that are not previously acceptable for heap leaching (HL) technology – these are refractory ores with thin and ultrafine inclusions of precious metals, ore with an increased silver content. In the Russian Federation, classical representations in the field of gold and silver HL prevail in design solutions. At the same time, the problem of silver leaching is considered in terms of the associated extraction of the main component. This approach is determined by a limited set of technological measures that have become an integral part of the classic technological regulation: ore crushing to the class –200–40 mm, sodium cyanide consumption at the level of 0,5 kg/t; pH value – 10,5; cycle duration 65 days or more; gold concentration in production solutions – fractions, mg/l; using activated carbon for sorption of noble metals. Processing ores with silver contents of 30 g/t and a more classical approach to gold HL does not allow to increase the degree of extraction. There is a need to modernize the circuit or change the parameters of the technological regulations. The object of the study was a sample of poor quartz ore provided by the customer developing one of the gold and silver deposits of the Far Eastern Federal District, the object was to increase the degree of leaching of silver from poor gold-bearing ores without changing the technological scheme and without attracting additional mining equipment. Critical analysis of literary data was carried out and the main directions of gold production from poor gold-bearing ores were identified. Chemical and mineralogical compositions of silver-containing minerals and ore rocks were investigated. Forms of association of silver with ore minerals and rocks have been established. The option of physical and chemical activation of increase of reactivity of cyanide solutions during heap leaching of silver from poor gold-bearing ores is chosen. In laboratory conditions, it was found that an increase in the concentration of sodium cyanide by 6 times or more contributes to a satisfactory extraction of gold both in agitation and percolation leaching of silver. However, in the latter case, the positive result was obtained only with the use of solutions with increased reactivity
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Santos-Munguía, P. C., F. Nava-Alonso, V. M. Rodríguez-Chávez i O. Alonso-González. "Hidden gold in fire assay of gold telluride ores". Minerals Engineering 141 (wrzesień 2019): 105844. http://dx.doi.org/10.1016/j.mineng.2019.105844.
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Chen, T. T., L. J. Cabri i J. E. Dutrizac. "Characterizing gold in refractory sulfide gold ores and residues". JOM 54, nr 12 (grudzień 2002): 20–22. http://dx.doi.org/10.1007/bf02709181.
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Spry, Paul G., Stephen Chryssoulis i Christopher G. Ryan. "Process mineralogy of gold: Gold from telluride-bearing ores". JOM 56, nr 8 (sierpień 2004): 60–62. http://dx.doi.org/10.1007/s11837-004-0185-4.
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Malyutina, A. V., Yu O. Redin, A. S. Gibsher i V. P. Mokrushnikov. "SPATIOTEMPORAL AND GENETIC RELATIONSHIPS OF GOLD ORE AND MERCURY-ANTIMONY MINERALIZATION AT THE HG-SB-GOLD-BEARINGCHAUVAI DEPOSIT (KIRGHIZIA): GEOLOGY, MINERALOGY OF ORES AND FEATURES OF HYDROTHERMAL-METASOMATIC PROCESSES". Geology and mineral resources of Siberia, nr 3 (2021): 61–82. http://dx.doi.org/10.20403/2078-0575-2021-3-61-82.
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The Chauvai Hg-Sb deposit is a striking example of combining two contrasting types of mineralization in space: mercury-antimony and gold ones. The article studies the spatial-temporal and genetic relationships of goldore and mercury-antimony mineralization based on a complex of both traditional geological and mineralogicalgeochemical methods, as well as modern instrumental methods for analyzing the mineral composition. Two types of ores with clear structural confinedness have been found at the deposit: a) mercury-antimonic (cinnabarantimonite) ores, associated with jasperoid breccias and manifested exclusively along the tectonic contact of limestone of the Alai section and terrigenous rocks of the Tolubai Formation, and b) gold- sulphide (arsenopyritepyritic) ores, localized in slightly modified carbonate-terrigenous rocks of the Tolubai Formation, overlying the plane of tectonic contact. Ore formation occurred during the following stages: in the late diagenetic, without interruption passing into the catagenetic-hydrothermal, characterized by the formation of gold mineralization, and then in the later hydrothermal-telethermal, characterized by the development of Hg-Sb mineralization. It is established that the main carrying agent of invisible gold (“invisible gold”) in ores is framboidal and idiomorphic pyrite and, especially, its high-arsenic varieties. A set of conducted studies has shown that the gold ore and mercury-antimony mineralization is broken in time and is genetically associated with various hydrothermalmetasomatic processes, and the Chauvai deposit can be classified as a Carlin-like type.
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Motov, Andrey, i Alexander Sobolev. "Phylogenesis of gold in polymetallic volcanogenic-sedimentary massive sulfide ores". Ores and metals, nr 2 (11.07.2023): 64–77. http://dx.doi.org/10.47765/0869-5997-2023-10009.
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The Au concentrational level of the ores of polymetallic volcanogenic-sedimentary massive sulfide deposits is predetermined by the geodynamic setting of their formation. The ores formed in a mid-ocean ridge setting are characterized by low Au grades. The ores formed under the island arc conditions possess higher Au contents. In the course of the further existence of the ore deposit, its ores experience repeated external influences: underwater halmyrolysis, thermal and dynamic metamorphism, hydrothermal-metasomatic transformations, and exogenous oxidation. These processes lead to the transfer of gold from a micro- or nano-sized form in the sulfides to the free form and to redistribution of Au over the ore field of the deposit. The heterogeneity of the ores in terms of the Au content and existence forms must be taken into account when preparing a feasibility study. The work is intended for geologists conducting mining and geological modeling, designing techniques for the ore extraction, and proposing ore processing technologies.
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Solodenko, A. A. "INVESTIGATIONS OF GOLD BEARING ORES BENEFICATION". Izvestiya Vuzov. Tsvetnaya Metallurgiya (Proceedings of Higher Schools. Nonferrous Metallurgy), nr 3 (27.02.2015): 15. http://dx.doi.org/10.17073/0021-3438-2014-3-15-20.
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Zhang, Jian, Yao Zhang, William Richmond i Hai-peng Wang. "Processing technologies for gold-telluride ores". International Journal of Minerals, Metallurgy, and Materials 17, nr 1 (luty 2010): 1–10. http://dx.doi.org/10.1007/s12613-010-0101-6.
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