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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 submitted2018-05-16
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Date accepted2018-07-22
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Date published2018-10-24
Extraction of copper, cobalt and nickel ions from aqueous solutions by extractant CYANEX 272
- Authors:
- L. A. Voropanova
- V. P. Pukhova
The extractant CYANEX 272, which active component is di(2,4,4-trimethylpentyl)-phosphinic acid (C 8 H 17 ) 2 POOH, is effective for extraction of copper (II), cobalt (II) and nickel (II) ions. The extraction of metal ions using di(2,4,4-trimethylpentyl)-phosphinic acid as an extractant is carried out due to the formation of an organophosphorus complex with wide pH range: copper at pH > 2, cobalt at pH > 3, and nickel at pH > 5. They are extracted with an organic phase: copper at pH = 3-7, cobalt at pH = 4-7, and nickel at pH = 6-9, and precipitate in the organophosphorus compound: copper at pH > 7, cobalt at pH ≥ 8, and nickel at pH ≥ 10. The possibility of separation of copper (II) and cobalt (II) is insignificant, the stripping of copper (II) and nickel (II) happens at pH = 4-6, and the stripping of cobalt (II) and any of nickel (II) – at pH = 5-6. The obtained results of ion extraction of the investigated metals can be used not only for processing of technological solutions, but also for purification of effluents from industrial enterprises and mine waters, heap and underground leaching solutions, etc. from the ions of studied metal ions.
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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 submitted2015-08-14
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Date accepted2015-10-07
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Date published2016-04-22
Extraction of ions of silver from hydrochloric acid solutions by tributylphosphate
- Authors:
- L. A. Voropanova
- N. B. Kokoeva
The high results of the silver ions extraction from the hydrochloric acid solutions of tributylphosphate during extractant portional introduction were obtained. The extractant batch inclusion increases silver extraction process and reduces the extractant expenditure. The best extraction results were obtained for the solutions with concentration 3N HCl, 240 NaCl g/dm 3 and temperature t = 20 °C. The principal technological scheme of the silver ions extraction from the hydrochloric acid solutions is presented.
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Date submitted2015-07-27
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Date accepted2015-09-17
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Date published2016-02-24
Electroextraction of cobalt from sulfate-chloride and sulfate solutions of cobalt and manganese in static conditions
- Authors:
- L. P. Khomenko
- L. A. Voropanova
The dependence of the results of electroextraction cobalt and manganese from aqueous solutions of their sulphate and chloride-sulfate solutions under static conditions was investigated. According to the results of current efficiency and specific energy consumption it has been found that the electrowinning of cobalt from aqueous solutions of cobalt and manganese in static conditions using a titanium cathode should be carried out at low concentration of manganese from sulphate-chloride solution without partitions and from sulphate solutions both without and with the perforated partitions separating the electrolytic cell into cathode and anode space.
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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 submitted2014-10-15
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Date accepted2014-12-23
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Date published2015-08-25
Nickel electrolyte purification from ferrum (III) and copper (II) impurities by extraction using a mixture of oleic acid and triethanolamine
- Authors:
- L. A. Voropanova
- N. T. Kisiev
The conditions of the selective and joint extraction of copper and ferrum impurities from a nickel electrolyte by extraction using a mixture of oleic acid and trietanolamine in kerosene were determined: extraction Fe (III) at 3 < рН ≤ 4, 1 ≤ В:О ≤ 4 and t = 40 °C; extraction Cu (II) at 5 ≤ рН ≤ 6, 1 < В:О ≤ 4 and t = 40 °C; joint extraction of copper and ferrum at рН = 5-6, 1 ≤ В:О ≤ 4 and t = 40 °C. The process flow sheet of selective extraction of ferrum and copper from a nickel electrolyte by extraction using a mixture of oleic acid and triethanolamine in kerosene is given.
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Date submitted2014-10-27
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Date accepted2014-12-28
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Date published2015-08-25
Extraction of rare earth metals of di-2-ethylhexyl phosphoric acid from phosphoric solutions
- Authors:
- O. V. Cheremisina
The paper is devoted to solvent extraction of rare earth metals exemplified by Сe, Y from standard test and industrial solutions of wet-process phosphoric acid with di-2-ethylhexyl phosphoric acid used as extractant. The mechanism of rare earth metals extraction with di-2-ethylhexyl phosphoric acid was determined and studied on the basis of calculated thermodynamic characteristics. The paper considers the influence of impurity ions (Fe 3+ , Mg 2+ , ) on extraction of rare earth metals using industrial solutions. It has also been determined that for a stripping process the use of sulfuric acid solutions in concentration of 2 mol/l is the most preferable.
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Date submitted2014-07-13
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Date accepted2014-09-13
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Date published2014-12-22
Separation and extraction of lanthanides from low concentrations of raw materials using extraction methods
- Authors:
- T. E. Litvinova
- O. V. Cheremisina
At the present time, the unique physical and chemical properties of rare earth metals (REM) mean they can find wide application in the metallurgy, mechanical engineering, avionics, petrochemical, laser and glass industries. In metallurgy, rare earth metals using for production of special grades of steel and cast iron. Adding REM can improve their mechanical properties: hardness, toughness, resistance to corrosion. REM are also used for the deoxidation of metals and alloys. The REM production technology from loparite concentrate that already exists in Russia is not enough for the metal-lurgical, oil, glass, ceramic, nuclear and military industries (just 2 % of the world’s REM are produced in Russia). REM for these industrial proposes is purchased in China, which is recog-nized as having a monopoly on the production of rare metals (96% of REM produced world-wide). If we want to supply these needs in future, we will have to produce 10 tons per year of REM, which requires processing all available resources: mono- and polymineral raw materials. One of the most acceptable source of rare earth metals and some rare metals (zirconium, niobium, hafnium) is eudialyte. The world’s biggest deposits of eudialyte are found on the Kola Peninsula in northwest Russia, near the Lovozero mining and processing plant. Eudialyte concentrate is easily decomposed by acids, which explains its layered structure and weak chemical bonds between its constituent groups. The easy leaching process is the main reason that it is processed. In our work the technological possibility of extraction and separation of lanthanides has been shown, using solutions of naphthenic and oleic acid in an inert diluent with a stoichiometric reagent consumption, without the preoxidation step of the cerium to the tetravalent state. The technological parameters and stages of the process have been established.
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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 submitted2008-10-06
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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.