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Date submitted2023-11-02
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Date accepted2024-09-24
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Date published2025-02-12
Mercury contamination of sediments at Indonesia Ciujung watershed: contribution of artisanal small-scale gold mining
Artisanal small-scale gold mining is the largest artificial source of mercury pollution and has been a very common problem recently. This study examined the contribution of Hg release due to artisanal small-scale gold mining in contaminating the sediment of the watershed in Indonesia. Different from other methods, we measured Hg pollution using the stable isotopes of carbon and nitrogen. This report is the first time analytical reports in Indonesia since most papers focus primarily on only detecting heavy metals in river water and sediments, neglecting deep research on Hg pollution and resources. The findings of this study indicate that artisanal and small-scale gold mining activities, located in the upstream areas of the tributaries that act as point sources, are the primary source of mercury in the sediment of the Ciujung watershed. The isotopes δ13C and δ15N successfully trace the Hg-contaminated sediment in the Ciujung watershed derived from the Cisimeut and Ciberang Rivers based on soil organic matter. The biological effect showed the Hg concentration in most of the sampling sites exceeded the Effects-range medium and Probable effect limit values. The Risk quotient values of Hg indicated the Hg pollution had a possibility effect on the benthic organism. Several limitations have also been added in this study and needs for further investigation.
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Date submitted2024-05-03
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Date accepted2024-09-05
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Date published2024-11-12
Platinum group elements as geochemical indicators in the study of oil polygenesis
This study examines elements of the platinum group (PGE), primarily platinum and palladium, as geochemical indicators in the investigation of oil polygenesis. It has been found that, like other trace elements such as nickel, vanadium, and cobalt, platinum group elements and gold can occur in oil fields at both background levels and in elevated or even anomalously high concentrations. The objective of this research is to analyze PGE and trace elements as geochemical markers to identify the geological factors, including endogenous processes, responsible for these unusually high concentrations in oil. A comprehensive review of the literature on this subject was conducted, along with new data on the presence of precious metals in oils from Russia and globally. The study explores the geological mechanisms behind elevated PGE concentrations in oils, utilizing atomic absorption spectroscopy with atomization in the HGA-500 graphite furnace to measure PGE content. Previously, the tellurium co-deposition method (ISO 10478:1994) was used to isolate noble metals from associated elements. Possible geological origins of abnormally high concentrations of platinum metals in oils have been identified. These include endogenous factors such as the spatial proximity of oil fields to ultrabasic rock massifs, the effects of contact-metasomatic processes, and influences from mantle dynamics. Moreover, data concerning mantle elements can serve as indicators of the depth origins of certain hydrocarbon fluids, thus contributing to the study of oil polygenesis.
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Date submitted2024-04-12
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Date accepted2024-09-05
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Date published2024-11-12
Promising reagents for the extraction of strategic metals from difficult-to-enrich mineral raw materials
The need of the mining and processing industry for new types of directional reagents is due to the deterioration of the material composition of the processed ores. Low Au content (less than 0.5-1.0 g/t), finely dispersed Au inclusions (0.1-10.0 microns) in the ore, similar properties of the separated minerals have an extremely negative effect on flotation performance when using traditional reagents, which leads to significant losses of valuable metal with enrichment tailings. Expanding the range of domestic flotation reagents based on the latest achievements of fundamental research and their targeted application at mining and processing companies will compensate for the negative impact of the mineral composition of raw materials and ensure maximum extraction of strategic metals from difficult-to-enrich ores. The use of modern research methods (scanning electron and laser microscopy, UV spectrophotometry, XRF and chemical analysis) made it possible to visualize the adsorption layer of new reagents-collectors of a number of dithiocarbamates with different structures of a hydrocarbon radical and an organic modifier on the surface of gold-containing sulfides. The amount of adsorbed reagents on the surface of minerals has been experimentally determined. The specific features of the fixation of reagents on minerals of various compositions led to optimal correlations of their consumption in the flotation process. Scientifically based reagent regimes ensured an increase in the gold content in the concentrate and a decrease in the loss of gold with tailings by 5-6 % during flotation enrichment of the refractory ore of the Malinovskoe deposit.
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Date submitted2023-03-01
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Date accepted2024-06-03
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Date published2025-02-25
Lamprophyres of the Peshchernoe gold deposit, their geological position, material composition, and metasomatic alterations (Northern Urals)
The article presents the first data on biotite-hornblende lamprophyres discovered at the Peshchernoe gold deposit. We consider the geological position of lamprophyre dikes in the deposit structure and the relationship of these rocks with tectonically weakened and mineralized zones. The data on the structural position of mineralized zones, faults, dike bodies, metasomatic halos, and host volcanogenic-sedimentary rocks confirm the tectonic nature of the Peshchernoe deposit alteration system. Lamprophyre dikes are pre-ore, as evidenced by the superimposed metasomatic mineral associations. We assume that dikes of andesitic rocks, lamprophyres, and subsequently hydrothermal fluids, including ore-bearing ones, were intruded along the fault zone of northeastern strike at different geological times. The description of mineralogical and chemical transformations of lamprophyres, which occurred as a result of alteration, is given. Two stages of metasomatism are distinguished: carbon dioxide (beresitization-listvenitization) and subsequent alkaline (sodic metasomatism). During carbon dioxide metasomatism, dark-coloured minerals are replaced by chlorite, albitization and sericitization of plagioclase occur, and ferruginous dolomite is formed under the influence of a significant supply of CO2. Alkaline (sodic) metasomatism is superimposed on the mineral metasomatic paragenesis of the first stage. We consider metasomatic zoning during sodic metasomatism, manifested in one of the spessartite dikes. Chlorite and relics of magmatic dark-coloured minerals are replaced by magnesite, the supply of Na leads to the appearance of newly formed albite, and the supply of S leads to the formation of pyrite, which concentrates iron from other minerals. As a result of the sodic metasomatism, iron content in carbonates decreases in the direction from the outer metasomatic zone to the inner one. We conclude that it was the alkaline-sulphide sodium solutions that performed the ore-bearing function, and beresitization and listvenitization prepared a favourable environment for ore deposition.
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Date submitted2023-07-07
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Date accepted2023-09-20
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Date published2024-02-29
Isotherm and kinetic adsorption of rice husk particles as a model adsorbent for solving issues in the sustainable gold mining environment from mercury leaching
One of the techniques used in extracting gold in small-scale gold mining is mercury amalgamation. However, the use of mercury presents significant health and environmental hazards, as well as suboptimal efficiency in gold extraction. This study explores the possibility of the use of rice husk as a prototype adsorbent for mercury removal from its leaching in mining environments. To support the analysis, the rice husk adsorbent was characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, electron dispersive X-ray spectroscopy, atomic absorption spectrophotometers and Brunauer − Emmett − Teller analysis. To investigate the removal of Hg from aqueous solutions, batch adsorption experiments were conducted, and the efficiency was optimized under various parameters such as contact time, rice husk dosage, and initial concentration of mercury. Kinetic and isotherm investigations were also carried out to gain a better understanding of the adsorption properties. The kinetic adsorption was analyzed using the pseudo-first-order and pseudo-second-order. Furthermore, the isotherm adsorption was analyzed using ten adsorption isotherm models (i.e., Langmuir, Freundlich, Temkin, Dubinin – Radushkevich, Flory – Huggins, Fowler – Guggenheim, Hill – de Boer, Jovanovic, Harkin – Jura, and Halsey). The amount of mercury absorption increased with increasing contact time, adsorbent mass, and initial concentration of mercury. The pseudo-second-order kinetic model is the best model that can be applied to describe the adsorption process. Analysis of the adsorption results obtained shows that the adsorption pattern is explained through the formation of a monolayer without any lateral interaction between the adsorbate and adsorbent. In addition, the formation of multilayers due to inhomogeneous pore distribution also occurs which causes a pore filling mechanism. We found that the isotherm phenomena are near the Jovanovic models with the maximum adsorption capacity) of rice husk found to be 107.299 mg/g. As a result, rice husk could be a promising option for wastewater treatment due to its fast and efficient removal capacity, as well as its affordability and eco-friendliness. The predicted thermodynamic studies using the Flory – Huggins isotherm model show that the adsorption process is endothermic, spontaneous, and physisorption. The impact shows that the utilization of rice husk can be used and fit for the current issues in the sustainable development goals (SDGs).
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Date submitted2021-04-15
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Date accepted2022-09-06
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Date published2023-10-27
Gold-rare metal and associated mineralization in the western part of Bolshevik Island, Severnaya Zemlya archipelago
The presented studies are aimed to determine the formation patterns of the gold-rare metal mineralization within one of the most inaccessible Arctic islands of the Russian Federation, Bolshevik Island of the Severnaya Zemlya archipela-go. The relevance of the work is determined by the high probability of discovering a significant in terms of metal reserves deposit, which is proved by many researchers on the example of known large deposits to be a typical feature of sites with gold-rare metal formation. Obviously, only the possibility of discovering and subsequent development of a deposit of a highly liquid type of mineral, gold, can ensure the profitability of mining production on Severnaya Zemlya. It is established that the main geological, mineralogical, and geochemical features of the gold-rare metal mineralization in the Kropotkinsko-Nikitinskaya metallogenic zone of Bolshevik Island correspond to that of similar ore sites in Russia and the world. The occurrences of other formation types revealed in this metallogenic zone suggest a certain zoning in their distribution: mineralization is located in the apical parts of granitoids and in the nearest halo of hornfelses. At a distance, with an exit from the hornfelsed zone, there are occurrences of a cassiterite-sulphide formation with elevated gold and silver content at the top of the ore column, together with an increased amount of polymetallic ores. Occurrences of gold-quartz and gold-sulphide-quartz formations are localized in fault zones, as a rule, farther from granitoids. The total vertical range of gold mineralization exceeds 300 m. The assignment of all types of mineralization in the Kropotkinsko-Nikitinskaya metallogenic zone of Bolshevik Island to a single hydrothermal process is emphasized by the similar isotope composition of lead galena from heterogeneous occurrences, which determines the age of all mineralization at 200-300 Ma.
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Date submitted2022-06-20
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Date accepted2022-09-06
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Date published2022-11-03
Adaptive approach formation using machine vision technology to determine the parameters of enrichment products deposition
In this paper, an adaptive approach has been developed for automatic initialization of the thickening curve using machine vision technology, which makes it possible to determine with high accuracy the material parameters necessary for the design of thickening and clarification apparatuses. Software has been developed that made it possible to search for the coordinates of the condensation critical point in automatic mode. Studies on two samples of materials (tailings of apatite-containing ores and gold-bearing concentrate) were carried out and made it possible to statistically prove the reproducibility of the results obtained using the parametric criteria of Fisher and Bartlett. It has been established that the deposition curves are approximated with high accuracy by the Weibull model, which, together with the piecewise linear approximation, makes it possible to formalize the method for determining the critical point coordinates. The empirical coefficients of the Weibull model for two samples are found, and the final liquefaction and settling rates of the studied materials are determined.
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Date submitted2022-03-22
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Date accepted2022-06-15
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Date published2022-07-26
Gold in biogenic apatites of the Baltic-Ladoga phosphorite basin
- Authors:
- Sergey B. Felitsyn
- Nadezhda A. Alfimova
The distribution of gold in biogenic apatites from the Ordovician deposits in the northwest of the East European Platform shows that the maximum concentration of gold in apatites is found within the Ladoga-Baltic suture zone. Gold mineralization has a superimposed character, which is confirmed by the dependence of the gold content on the size of apatite particles and a number of isotope geochemical systematics in biogenic apatites. Gold is present in the form of high fineness particles to 20 µm in size on the surface of biogenic apatite fragments (phosphate brachiopod shells and conodont elements) and is easily extracted. In 10 % of samples of biogenic apatites, the total content of rare earth elements is more than 1 wt.%.
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Date submitted2022-04-06
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Date accepted2022-06-15
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Date published2022-07-26
Geological and structural position of the Svetlinsky gold deposit (Southern Urals)
The paper presents the geological and structural position of the large Svetlinsky gold deposit in the Kochkar anticline (Southern Urals), localized in the zone of the Late Paleozoic (D 3 ) deep thrust of the western dip. The study confirms and clarifies the notion of its multiphase and polychronism. The thrust caused bending moments in its wings, subsidence of the lying crust, emergence of a shallow marine basin with rapid accumulation of terrigenous carbonate sediments (C 1 v), and formation of numerous landslide structures. The heating of rocks in the anticline core was accompanied by granitization and dome formation. A small Svetlinsky dome formed in the immediate vicinity of the thrust, creating a thermobaric gradient field (С 2 ). The zone of dome dynamic influence also includes the adjoining thrust area, complicated by a series of sub-vertical thrusts of sub meridional strike and numerous steeply dipping subparallel cracks of the latitudinal strike, synchronously filled with vein quartz and accompanied by hydrothermal metasomatic rock transformations. The formation of the gold deposit occurred during the post-collisional relaxation stage (from P 1 to, probably, the Early Jurassic). The association of gold mineralization with the Svetlinsky dome is indicated by the presence of native gold in Neogene ravine placers in the dome area and marbles of the Svetlinsky deposit, in association with fluorite, F-phlogopite, Cr-muscovite, pink topaz, pure quartz, and native sulphur. The presence of native gold in Neogene ravine placers in the dome area and marbles of the Svetlinsky deposit, in association with fluorite, F-phlogopite, Cr-muscovite, pink topaz, pure quartz, and native sulphur, indicates the association of gold mineralization with the Svetlinsky dome.
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Date submitted2021-06-24
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Date accepted2021-11-30
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Date published2021-12-27
Development of a methodology to assess the hydrocyclone process with account of the rheological properties of the mineral slurry
- Authors:
- Tatiana N. Aleksandrova
- Vadim A. Potemkin
The paper studies the possibility of assessing the separation of mineral raw materials, taking into account the rheology of the mineral slurry. The ores of the Mayskoye deposit were chosen as the object of the study, characterized by a thin impregnation of the valuable component – gold in the host minerals, which determines the use of fine and ultrafine milling. This fact is essential because the presence of a fine grade seriously affects the rheology of the mineral slurry used in subsequent mineral processing stages. This predetermines the necessity to take into account rheological parameters. The research performed provides the development of a methodology for assessing the separation of minerals in the hydrocyclone based on the interpretation of numerical and mathematical modeling data. using the object-oriented programming language Python, a program for calculating empirical coefficients of the rheological equation, theoretically describing the dynamics of internal transformations of the mineral slurry, was developed. Taking into account the process parameters of the laboratory unit with hydrocyclone and ore properties, three concentrations of solids in the mineral slurry were selected, conditionally corresponding to the minimum, average and maximum values. Rheological equations successively composed for three concentrations, i.e., 400, 500, and 700 g/l, made it possible to calculate the critical shear rates corresponding to the maximum dispersion of the mineral slurry in the hydrocyclone flow. Subsequent numerical simulation using Ansys Fluent software, as well as statistical evaluation of the shear rates at different levels of solids content showed that the shear rate profile in the cross-section of the hydrocyclone corresponding to the maximum dispersion of the mineral slurry is obtained at the content of 400 g/l.
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Date submitted2020-09-15
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Date accepted2021-11-30
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Date published2021-12-27
Evaluating the effectiveness of fine gold extraction technologies on the example of titanomagnetite beach placers of the western coast of Kamchatka
- Authors:
- Valentina E. Kungurova
The material on the gold content of coastal-marine deposits of the western coast of Kamchatka is analyzed and the resource potential is briefly characterized. A review of gold technological estimates obtained from the study of gold-bearing samples taken in promising areas of the coastal-marine strip, from the Bolshaya Vorovskaya River in the north to Cape Levashova in the south, is presented. Stock materials supplemented by our studies were used. Gold-bearing deposits with very fine (0.05-0.1 mm) and fine (0.1-1.0 mm) gold amounting to 94.6 % were tested, as well as samples with gold up to 2 mm and more in addition to fine gold The content of freely recoverable gold reached 91.9 %. In the case of significant gold reserves in placers, prospects for their commercial development open up. experiments on the enrichment of gold-bearing coastal-marine deposits of Western Kamchatka indicate the possibility of extraction of free gold and other valuable components from them. Gravity technologies and modern equipment developed by ОАО Irgiredmet and JSC ITOMAK are the most effective for their extraction. enrichment of gold-bearing formations with simultaneous extraction of several useful components from them, which is possible with the use of fluoride technology, can also become economically advantageous.
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Date submitted2021-03-11
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Date accepted2021-07-27
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Date published2021-10-21
Justification of a comprehensive technology for preventing the formation of asphalt-resin-paraffin deposits during the production of highlyparaffinic oil by electric submersible pumps from multiformation deposits
Production of highly solidifying abnormal oils (with a paraffin content of over 30 % by mass) in the Far North is complicated by the intensive formation of asphalt-resin-paraffin deposits (ARPD) in the bottomhole zone of the productive formation, well and surface equipment. Existing methods and technologies for countering the formation of organic deposits in well equipment have many advantages. However, their application in the production of highly paraffinic oil does not fully prevent the formation of ARPD in the tubing string. This leads to a significant reduction in oil production, reduction of turnaround and intertreatment periods of production wells operation, an increase in specific operating expenses for paraffin removal. Results of theoretical and laboratory investigations presented in the article show that one of the promising ways to improve the operational efficiency of wells equipped with electric submersible pumps during extraction of highly paraffinic oil from multiformation deposits is the application of a new integrated technology based on the joint production of highly solidifying abnormal oil with oil, characterized by a lower paraffin content and manifestation of structural and mechanical properties, in conjunction with the regulation of the parameters for the electric submersible pump. Results of numerical modeling using the PIPESIM steady-state multiphase flow simulator, physical, chemical and rheological investigations show that with a decrease of highly paraffinic oil from the productive formation D2ef in a blend with Stary Oskol oil from the Kyrtaelskoye field, a decrease in the mass content of paraffin in the blend and the temperature of its saturation with paraffin, depth and intensity of the organic deposits formation in the tubing string, pour point, as well as the improvement of the rheological properties of the investigated structured dispersed systems is observed. Article describes a promising assembly of well equipment for the single tubing separate production of highly paraffinic oil from multiformation deposits of the Timan-Pechora province, providing separation of the perforation zones in two productive formations using a packer-anchor system at simultaneous-separate operation of the formations by a double electric submersible pump unit.
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Date submitted2020-09-10
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Date accepted2020-11-25
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Date published2021-06-24
Formation conditions of noble metal mineralization in sulfide cobalt-copper-nickel ores of Kamchatka (on the example of Annabergitovaya Schel ore occurrence)
The authors present research results, the purpose of which is to study the specifics of noble metal mineralization and its genesis in sulfide cobalt-copper-nickel ores of the Kamchatka nickel-bearing province. The paper is dedicated to one of its many ore occurrences called Annabergitovaya Schel (Annabergite Gap). The material composition of platinoid, silver, gold, bismuth and tellurium minerals, as well as sulfarsenides in the ores of this occurrence was investigated. Based on the data of mineral formation sequence and the use of geosensors, conclusions were drawn regarding the genesis of noble metal mineralization. Formation of platinoid minerals, silver and gold at the Annabergitovaya Schel ore occurrence is mainly associated with the epigenetic effect of post-ore granitoids on ore-bearing intrusion rocks of the Dukuk complex of the cortlandite-norite formation and on syngenetic ores. An early association of noble metal minerals is represented by sperrylite, irarsite, and rare unnamed phases of Pt + Ir + Te. Irarsite and Pt + Ir + Te phases were formed at the contact-metasomatic stage. Sperrylite can be assumed to be of magmatic origin. Silver sulfides and tellurides, silver and palladium bismuth tellurides, and native gold were formed at the late, hydrothermal-metasomatic, stage. The occurrence conditions of mineral parageneses, associated with noble metal mineralization, correspond to the formation of shallow-depth metasomatic rocks (≤5 km). Sub-developed quartz-feldspar metasomatites, associated with the formation of early platinoid arsenides and sulfarsenides, are in equilibrium with circumneutral solutions (pH of 4.5-6.5) at temperatures of 350-600 °C. Late hydrothermal association with Pd, Ag and Au minerals is close to propylites and was formed at pH values of 4.5-6.5 and temperature of 150-350 °C.
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Date submitted2019-06-06
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Date accepted2019-08-09
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Date published2020-04-24
Studies of enrichment of sulfide and oxidized ores of gold deposits of the Aldan shield
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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Date submitted2018-09-12
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Date accepted2019-01-05
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Date published2020-04-24
Flotation extraction of elemental sulfur from gold-bearing cakes
- Authors:
- Svetlana A. Ivanik
- Dmitrii A. Ilyukhin
Currently, in the development of the raw materials base of the gold mining industry, there is a tendency to reduce the quality of the initial mineral raw materials due to the depletion of reserves of rich gold-bearing ores. The article discusses the technology of extraction of refractory gold-bearing concentrates based on low-temperature leaching of pyrite concentrate. A decrease in the parameters of the autoclave oxidation of sulfide minerals, such as pyrite and arsenopyrite, leads to the incomplete extraction of gold into the solution and, consequently, its losses during subsequent cyanidation. As a possible option for a more complete extraction of gold using low-temperature oxidation technology, a method of flotation separation of elemental sulfur from leaching cakes is proposed. According to the basic process flow chart, the flotation process designed for gold extraction is carried out after autoclave oxidation, but before cyanidation. A series of experiments were carried out with varying reagent conditions and the dependence of gold losses on the extraction of elemental sulfur in the flotation tailings was established. As determining factors, pH and solid content in the initial pulp were considered. The paper justifies the separation of elemental sulfur from autoclave cake to enriched sulfur concentrate. The cake flotation modes after autoclave oxidative leaching of pyrite concentrate are investigated. The distribution of elemental sulfur and gold by flotation products makes it possible to conduct the tailings cyanidation process with acceptable indicators.
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Date submitted2018-12-25
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Date accepted2019-03-22
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Date published2019-06-25
Technology of blasting of strong valuable ores with ring borehole pattern
- Authors:
- I. V. Sokolov
- A. A. Smirnov
- A. A. Rozhkov
The ores of non-ferrous and precious metals, represented by hard rocks, has a peculiar feature, that is the effect of segregation, that is the tendency of ore minerals to break down into small size classes, which in the underground mining method accumulate in significant quantities on uneven surface of bottom layers and subsequently are lost. When mining valuable non-metallic materials, there is an acute problem of overgrinding, when fines do not meet the requirements for the quality of the final product. It is well known that the granulometric composition of the ore depends mainly on the technology and parameters of drilling and blasting operations. In underground mining of ore deposits, the main method of drilling and blasting is the borehole blasting with continuous construction charges with the ring pattern. The main drawbacks of the method are: uneven distribution of the explosive along the plane of the broken layer and the expenditure of a significant part of the blast energy of the charges of the continuous structure on the blasting effect, necessarily associated with over-grinding the ore. To solve these problems, the authors proposed a blasting technology, the essence of which lies in the fact that the uniform distribution of the energy concentration of explosives in the broken layer is ensured by the dispersion of charges by air gaps and a certain order of their placement in the ring plane. For the practical implementation of the technology, a method has been developed to form dispersed charges in deep boreholes that do not require a significant increase in labor costs and additional special means. A special technique has been created that allows defining the dispersion parameters, ensuring the sustained specific consumption of explosives over the entire plane of the broken layer. Experimental studies of the proposed technology in the natural conditions of an underground mine for the extraction of valuable granulated quartz were carried out. As a result, the possibility of a significant reduction in the specific consumption of explosives (by 42 %) has been established. At the same time, the yield of the commercial product increased by 10.7 % in total, and the yield of the fraction most favorable for further processing increased by 33.7 %.
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Date submitted2018-11-10
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Date accepted2019-01-17
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Date published2019-04-23
AMT soundings in the dead band within the Chukotka region (Russian Far East)
The article analyzes the amplitude spectra of audio magnetotelluric sounding (AMTs) data. Particular attention is focused on the frequency range from 1 to 5 kHz, which is called dead band. We analyzed the data of base stations used in the fieldwork during the summer and autumn seasons in 2013, 2014, and 2017. The area of work is located in the Chukotka Autonomous Area beyond the Arctic Circle. Previous researchers noted that a reliable signal in the dead band can only be obtained at nighttime. The authors of the article found that in Chukotka region in the daytime against the minimum signal within the dead band there is a local maximum at a frequency of 2.4 kHz. When registering a field for more than 3 hours during daytime, in most cases, it is possible to restore the frequencies of 2.2 and 2.6 kHz. These frequencies are reliable benchmarks, allowing in some cases to restore the AMT curve using the correlation between amplitude and phase. We have proposed ways to improve data quality in the dead band when measured during the daytime.
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Date submitted2018-09-07
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Date accepted2018-11-08
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Date published2019-02-22
Assessment of refractory gold-bearing ores based on interpretation of thermal analysis data
- Authors:
- T. N. Aleksandrova
- G. Heide
- A. V. Afanasova
The article presents the results of a study on the possibility to assess refractory gold-bearing ores using thermal analysis data. It studies the flotation concentrates obtained during the enrichment of double refractory sulfide gold-bearing ores. This type of ore is complicated by the fine impregnation of gold in sulphide minerals and the presence of sorption-active scattered carbonaceous matter, which is in close association with sulphides. The results of thermogravimetric and mass spectrometric studies of refractory gold-bearing ores are presented. The obtained fragments for kerogen CH (m/z = 15), C 2 H (m/z = 29) and C 3 H (m/z = 43) indicate the presence of various types of carbonaceous matter in the studied samples. It is justified that the degree of sorption activity of carbonaceous matter depends on the presence of kerogen and bitumen in the ore. High sorption activity of scattered carbonaceous material significantly affects the processing technology of ores and concentrates, both flotation and pyro- and hydrometallurgical methods. Thermogravimetric and mass spectroscopic analyzes can be used to determine the degree of preg-robbing of refractory gold-bearing ores. The obtained results predetermine the direction of creating new methods and technologies in the field of decarburization of refractory gold-bearing ores in the integrated development of solid minerals in the mining regions of Russia.
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Date submitted2016-08-28
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Date accepted2016-11-04
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Date published2017-02-22
Deposits of gold-quartz formation in the Priamur province
- Authors:
- V. A. Stepanov
- A. V. Melnikov
A description of gold-quartz formation deposits in the Priamur gold province is presented. Prevalence of gold-quartz deposits defines metallogenic profile of the province and presence of numerous rich placers. Deposits are attributed to frontal, middle and near-bottom parts of the ore pipe. Frontal part of the ore pipe contains a major part of the deposits. They are small and consist of scattered quartz, feldspar-quartz and carbonate-quartz veins. The ore is characterized by erratic percentage of gold, bonanzas can be found. Gold is free, ranging from fine to big grains and small nuggets. It is associated with arsenopyrite, galenite, sometimes with antimonite. Among trace elements can be copper, mercury, antimony and arsenic. Prevalence of frontal deposits in the province points to significant prospects of finding a rich deep mineralization in the middle part of ore pipe. Middle part of the ore pipe contains intermediate and small deposits. Ore bodies are often represented by veined and veinlet-disseminated zones, sometimes zones of metasomatites. For gold-quartz ores, free native gold can commonly be found, usually of fine and very fine grain size. Among ore minerals, apart from arsenopyrite, pyrite and galenite, scheelite is frequently observed.
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Date submitted2015-12-19
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Date accepted2016-02-08
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Date published2016-12-23
A technique for selective extraction of ions of gold and silver from hydrochloric solutions with tributylphosphate
- Authors:
- L. A. Voropanova
- N. B. Kokoeva
Extraction is studied by tributylphosphate (TBP) of ions of gold and silver from hydrochloric solutions during the portional and single time feed of extractant in dependence of the initial concentration of metal ions, temperature, concentration of hydrochloric acid, the ratio of organic (О) and water W phases О:W. The initial solutions contained soluble complex chlorides of gold and silver. When dissolving metal chlorides in the solution of common salt and hydrochloric acid, water soluble coordinate compound are formed that contain complex anions [AuCl 2 ] – , [AuCl 4 ] – , [AgCl 2 ] – , [AgCl 3 ] 2– , [AgCl 4 ] 3– , et al. As an extractant we used the tri-butyl ether of phosphoric acid (С 4 Н 9 О) 3 РО hat belongs to oxygen containing neutral extractants. The formation of coordinate (complex) compounds of TBP and metal polychlorides may be treated as the process of solvation of the extracted metal salt by the extractant. For selective extraction of ions of gold and silver from their hydrochloric solutions by tributylphosphate it is run feeding the extractant portionally to the solution at the minimal time of contact between the solution and the extractant; it helps extracting gold almost completely with the few first portions of the extractant at concentrations of 2n HCl 240 g/dm 3 NaCl and the temperature t = 60°С. Meanwhile the extraction of silver is kept to a minimum. Silver is extracted almost completely after the extraction of gold is over; it is done with tributylphosphate as well at concentrations of 3n HCl, 240 g/dm 3 NaCl and the temperature t = 20°С.
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Date submitted2015-08-17
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Date accepted2015-10-18
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Date published2016-04-22
Platinum specialization of supergene nickel deposits on ultramafic massifs of the Urals
- Authors:
- I. V. Talovina
This paper presents an analysis of geochemical data obtained as a result of persistent research of the Buruktal, Ufalei, Elov and others supergene nickel deposits of the Urals on the content of precious metals. Content and distribution of platinum group elements, gold and silver in oxide–silicate nickel ores are compared with their content in initial dunite-harzburgite bedrock. It was revealed that all the PGE accumulate in supergene nickel deposits. Geochemical specialization of PGE mineralization of supergene nickel deposits is determined by palladium and platinum, while in dunite-harzburgite substrate of primary ophiolitic massifs major platinoids are ruthenium, osmium and iridium. Pt/Pd ratio is generally less than 1, i.e. palladium is dominating in them with some exceptions.
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Date submitted2015-07-24
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Date accepted2015-09-29
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Date published2016-02-24
Geochemical features and prospects of ore content in black slates in Tajmyr-Severnaya zemlya gold formation
- Authors:
- A. N. Evdokimov
- V. I. Fokin
- N. K. Shanurenko
Gold content, at least twice higher than the gold percentage abundance in Earth’s crust, has been discovered in a number of black slates formations in Tajmyr-Severnaya Zemlya gold province. The article shows the measurement data on organic carbon and ore elements concentrations in carbonaceous sediments, with pyrite, being their constituent, in the region. The dependence of ore elements availability, including gold, on sulphidisation degree in rocks has been identified in an ore bundle of Golyshevskaja strata. The comparison of gold concentrations in sampled monocrystals and pyrite aggregates has been carried out. It has been empirically supported that the content of gold, lead, molybdenum, cobalt, nickel and copper normally grows with the increase of sulphides quantity. Concentrations of chromium, manganese, tin, vanadium decrease respectively; however, titanium and zinc content remains unchanged.
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Date submitted2015-07-07
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Date accepted2015-09-16
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Date published2016-02-24
Activation of heap leaching of low-sulfide ores the invisible gold
- Authors:
- A. G. Sekisov
- Yu. I. Rubtsov
- A. Yu. Lavrov
This article deals with a physical-chemical model of heap leaching processes justifying new technological approaches to recovering dispersed forms of gold from ores, placer sands and deute-rogene mineral raw materials. The key process of this model includes lattice diffusion of high-energy hydrion minerals and hydroxyl-radicals formed as a result of photochemical and electro-chemical processing of initial reagent aqueous solutions. Active components of gas-water emulsions obtained while processing initial reagent solutions provide a structural and material trans-formation of a mineral lattice which concentrates clusters of dispersed gold creating conditions for its interacting with complexing compounds of process solutions. The article also considers the technological processes of activation heap leaching of dispersed gold from the Pogromnoe ore field and the results of the experiments conducted in percolators with their charge ranged from 3 to 100 kg. The results have proved the efficiency of using gas-water suspensions prepared in the pho-toelectrochemical reactor with active ion-radical oxidizing agents.
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Date submitted2014-11-01
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Date accepted2015-01-02
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Date published2015-10-26
Development of an environmentally safe gold extraction method from refractory ores using sodium thiosulfate as an extractant
- Authors:
- Yu. V. Sharikov
- Ilkka Turunen
The article presents the results of a mathematical model development for the process of gold leaching from gold-containing ores and concentrates. A mathematical model has been developed by analyzing the chemistry of reactions and mass transfer processes. On the base of a kinetic extraction model and a hydrodynamic complete mixing model a mathematical model of thiosulfate leaching process in various types batch reactors, complete mixing flow process vessels and complete mixing reactor columns with different numbers of vessels in a column has been developed. The effect of the number of reactors in a column has been investigated and optimal segmentation conditions have been found. Based on the investigation of the process using the mathematical model a control system structure has been designed to provide maximum conversion at the exit area of a reactor column.
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Date submitted2014-10-27
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Date accepted2014-12-21
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Date published2015-08-25
Productivity of ore and placer gold deposits of the priamur province
- Authors:
- V. A. Stepanov
- A. V. Melnikov
The article discusses ore and placer gold deposits of the Priamur province formed as a result of the Late Mesozoic collisions of geoblocks of the south-eastern framing of the Siberian craton and the Amur composite massif. Metallogenic zoning of the province displaying metallogenic zones and ore-placer sites is described. The article shows that the Priamur province is one of the main gold-bearing provinces of Russia with the level of gold ore (about 180 tons) and placer (about 1132 tons) gold. The predominance of placer gold in gold mining indicates significant opportunities to identify new gold deposits.