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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 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 submitted2019-10-17
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Date accepted2020-01-24
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Date published2020-04-24
Composition and probable ore igneous rocks source of columbite from alluvial deposits of Mayoko district (Republic of the Congo)
The article presents the results of optical, electron microscopic and electron microprobe studies of columbite group minerals, collected during heavy mineral concentrate sampling of alluvial deposits in the Mayoko region (Republic of the Congo). The aim of the study is revealing tantalum niobates ore body in this region. We found that these minerals in loose deposits are represented by two grain-size groups: less than 1.6 mm (fine fraction) and 1.6-15 mm (coarse fraction). The grains of both fractions belong mainly to columbite-(Fe), less often to columbite-(Mn), tantalite-(Mn) and tantalite-(Fe), contain impurities of Sc, Ti, and W. The crystals have micro-scaled zoning (zones varies slightly in the Ta/Nb ratio values) and contains a lot of mineral inclusions and veins represented by zircon, pyrochlore supergroup minerals and others. Columbite-(Fe) and columbite-(Mn) are characterized by an increased content of Ta 2 O 5 up to the transition to tantalite-(Fe) and tantalite-(Mn). This allows us to exclude the formation of subalkaline rare-metal granites, their metasomatites (albitites and greisenes) and carbonatites, from the list of possible columbite ore rocks source in the Mayoko district. Thus, beryl type and complex spodumene subtype rare-element pegmatites of the mixed petrogenetic family LCT-NYF (according to P.Černý) should be considered as a probable root source. The results of the research should be taken into account when developing the methodology for prospecting in this area.
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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.
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Date submitted2014-07-08
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Date accepted2014-09-08
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Date published2014-12-22
The development of methods for increasing the efficiency factor of gravitation extraction for fine and ultrafine gold from different genesis placers
- Authors:
- T. N. Aleksandrova
- V. B. Kuskov
The basis for and results of experimental studies for increasing the efficiency factor of gravitation extraction for fine and ultrafine gold from geogenic and man-made mineral formations with high clay content as well as alluvial placers are presented. The clayey gold-bearing placers of the Khabarovsk region in Russia’s Far East were used as the subject of research. These placers contain a substantial amount of fine particle gold and muddy material with hard washability, which are the main reasons for gold losses. One more object of research is a placer located in the Krasnoyarsk region, east Siberia. A special method of interpretation has been created for particle size distribution, using newly developed software which can increase the accu-racy of sedimentation analysis and predict the morphology of gold. It has been proved that one of the most promising ways in which to intensify the gravity processes can be effective preparation, including the chemical dispersion of gold dust before gravitational processing. Exploring the joint effect of sodium hexapolyphosphate and halogen oxidant on the efficiency of processing revealed that the combination of the peptization-coagulation cycles improves gold recovery. Also, the possibility of using concentration tables with various designs for production of rough concentrate is shown. The use of a new round disk concentrated table design enables metallurgi-cal results to be improved in comparison with shaking tables.
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Date submitted2010-07-28
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Date accepted2010-09-18
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Date published2011-03-21
Assessment of alluvial gold-bearing raw materials from the permafrost zone for justification of combined geotechnology of gold heap leaching
- Authors:
- S. B. Tataurov
The paper presents results of cryogenetic impact on mineral composition and geotechnological properties of alluvial gold-bearing raw materials of natural and man-made origin. In particular, distinctive features in mineral composition of alluvial deposits are described within the permafrost zone and outside it as well as the nature, mechanisms and peculiar features in reduction of man-made gold amalgams are shown. The results obtained were used to justify the expediency of implementation of the combined heap gold ore leaching technology at alluvial deposits in the permafrost zone, which includes preliminary concentration of coarse, medium and fine gold as well as the gold amalgam.
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Date submitted2008-10-09
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Date accepted2008-12-12
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Date published2009-12-11
New source of noble corundum in Kenya
- Authors:
- L. V. Kulachkov
- K. Kamwathi
- V. L. Shterhun
The large-scale occurrence of ruby and sapphire in Kenya is represented by contemporary river-bed and valley alluvial placers. The first ones are characterized by a high content of ruby (up to 10,4 ct/m 3 ), the second type is interesting due to the amount of forecasted resources: up to 2,3 million ct of ruby and 1,2 million ct of sapphire. It turned out to trace the mechanism of corundum concentrations forming, the mineral crystallized in Archean high-alumina gneisses affected by Precambrian basites (ultrabasites), and then survived a complicated way: – ancient eluvium – ancient alluvium – transportation by basaltic Pleistocenic magma – Holocenic weathering crust of volcanites – talus – contemporary alluvium.
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Date submitted2008-10-06
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Date accepted2008-12-10
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Date published2009-12-11
Appearance of entropy principle in distribution оf the gold mass while formation of minable gold mineralization
- Authors:
- S. V. Sendek
The rule of the entropy distributiveness for mass of the metal in gold ores is detected at different scale levels. This regularity is resulted as a consequence of redistribution of the gold and host rocks after their primary conditions. Revealing of those rules may allow reviewing the notions on nature and genesis of gold mineralizaition.
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Date submitted2008-10-21
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Date accepted2008-12-10
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Date published2009-12-11
Prediction and prospecting types of reflection of buried kimberlite fields in terrigenous diamond-bearing rocks
- Authors:
- V. N. Ustinov
On the basis of complex of lithologic-stratigraphic, mineralogical, facial-dynamic, paleogeomorphologic and morphogenetic features of post-kimberlitic terrigenous diamond-bearing rocks and reconstructed synchronous relief three prediction and prospecting types of reflection of buried kimberlite fields are distinguished. It is shown that ranging of diamondiferous territories to various types enables to direct exploration works to discovery of diamond deposits of the certain origin and makes possible to select proper prospecting technique. With the use of suggested criteria of research of promising territories the evaluation of diamond presence in the industrial regions of the Siberian, East-European and African-Arabian platforms is carried out.