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Date submitted2024-06-04
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Date accepted2025-01-28
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Date published2025-04-04
Impact of dry and wet magnetic separator process parameters on iron oxide removal from Egyptian feldspar ore
The demand for feldspar as a raw material in the ceramic industry is continuously increasing. Feldspar is abundant in the Earth's crust and typically found alongside other silicate minerals, as well as titanium and iron oxides. This study aims to reduce the iron oxide content in feldspar ore from the Wadi Zirib region and achieve an optimal grade of feldspar concentrate for various industrial uses. The research involved dry and wet magnetic separation techniques followed by leaching with oxalic and citric acids to minimize iron impurities and enhance optical properties. The factors affecting the dry magnetic separation, for feldspar size of –250+45 µm, were optimized using the Box – Behnken factorial design and a non-magnetic concentrate with 0.29 % Fe2O3 and an 92.19 % feldspar yield was obtained. The wet magnetic separation for feldspar fines of size –45µm was optimized and a concentrate with 0.27 % Fe2O3 was achieved. The acid leaching was conducted on the non-magnetic feldspar concentrates using oxalic and citric acid. Oxalic acid was more successful in reducing iron oxide of dry (to 0.19 %) and wet (to 0.12 %) non-magnetic feldspar concentrates. The optical properties of the leached concentrates were improved compared to the original sample, as the whiteness improved up to 90 %.
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Date submitted2024-03-22
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Date accepted2024-09-24
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Date published2025-02-25
Behaviour of cerium (III) phosphate in a carbonate-alkaline medium
- Authors:
- Tatyana E. Litvinova
- Stepan A. Gerasev
The article investigates the behaviour of rare earth metals in carbonate-alkaline systems. The results of experimental studies on rare earth element extraction from phosphogypsum, a large-tonnage industrial waste forming in production of phosphoric acid are presented. Using the liquid phase leaching method, it was possible to extract more than 53 % of rare earth elements from old phosphogypsum and more than 69 % from fresh phosphogypsum due to solid phase treatment with a 4 mol/l potassium carbonate solution at temperature 90 °C. The behaviour of model cerium (III) phosphate in a carbonate-alkaline medium is characterized: a solubility isotherm is obtained as well as the dependences of the degree of cerium extraction into solution on temperature, carbonate ion concentration, interphase ratio, stirring intensity, and pH. The ability of soluble rare earth element complexes to precipitate over time was established, which was confirmed using cerium and neodymium as an example. Within 240 h after the end of the experiment, approximately 25 % of cerium and 17 % of neodymium were precipitated from the liquid phase. A similar property was recorded in representatives of the light group and was not noted in elements of the heavy group. The ability to self-precipitate in future can serve as a basis for developing an alternative approach to separating rare earth metals into groups after extraction in a carbonate ion medium. Also, based on the analysis of experimental data, the mechanism of cerium (III) phosphate dissolution in a carbonate-alkaline medium was characterized. An assumption was made that rare earth metal phosphates dissolve sequentially passing into an insoluble carbonate and then into a soluble carbonate complex.
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Date submitted2024-05-02
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Date accepted2024-06-03
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Date published2024-07-04
Iron ore tailings as a raw material for Fe-Al coagulant production
The paper presents the results of experimental research into the recovery of Fe-Al coagulant from iron ore tailings (IOTs). The variables investigated in the laboratory tests included sulphuric acid concentration, temperature, leaching time, solid/liquid phase ratio (S:L) and the presence of stirring. The experiment determined the composition of the coagulant and the solid residue after leaching. The maximum iron content in the solution after leaching was obtained using 40 % H2SO4 at a temperature of 100 °C (or with stirring at 75 °C) and a contact time of 60 minutes. In this case, the iron yield was at the level of 25 % of the total content in the iron ore tailings. Chemical analysis of the solution obtained after leaching showed Fe and Al sulphate contents of 11 and 2 % respectively. In the next step, the efficiency of the coagulant was evaluated on model solutions of colour. The experimental results showed that the coagulant obtained from the iron ore tailings can be used for wastewater treatment in a wide pH range from 4 to 12 pH units. The solid residue after leaching is a fine-grained powder rich in silica, which can potentially be used as an artificial raw material in the construction industry. The research carried out in this thesis has shown that the extraction of coagulants from iron ore tailings can be considered as a way to extend the production chain of iron ore mining and to minimise the amount of tailings to be stored in tailing ponds. The technical solution presented in this work allows to comprehensively solve the problem of environmental protection by creating new target products for wastewater treatment from IOTs.
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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 submitted2022-05-06
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Date accepted2022-11-17
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Date published2023-02-27
Comprehensive study of filtration properties of pelletized sandy clay ores and filtration modes in the heap leaching stack
There are the results of a study of the factors determining the formation and changes in the filtration properties of a heap leaching stack formed from pelletized poor sandy-clay ores. An analysis of methods of investigation of filtration properties of ore material for different stages of heap leaching plots functioning is carried out. Influence of segregation process during stack dumping on formation of zones with very different permeability parameters of ore has been established by experimental and filtration works. The construction and application of a numerical model of filtration processes in pelletized ores based on laboratory experiments is shown. By means of solution percolation simulation at different irrigation intensities the justification of optimal stack parameters is provided in terms of the geomechanical stability and prevention of solution level rise above the drainage layer.
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Date submitted2022-04-14
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Date accepted2022-07-21
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Date published2022-11-03
In-situ leaching of molybdenum and uranium by percarbonate and chloride-hypochlorite solutions
In-situ leaching of molybdenum and uranium is becoming an increasingly common process. The features of the material composition of ores, leading to a decrease in their filtration properties, were considered. Activation leaching with leaching solutions that have undergone electrophotochemical activation before contact with the ore mass were studied. Activation preparation of leaching solutions promotes the synthesis of clustered water molecules with collectivized protons and hydroxyl ions, as well as active forms of oxygen and hydrogen. Cell leaching of molybdenum from mature tailings of the Shakhtaminsk deposit was studied experimentally. After pre-oxidation with an active carbonate solution, a model borehole leaching was carried out with a chloride-hypochlorite solution. Molybdenum extraction on resin a was 85 % in 30 days. Experiments on the percolation leaching of uranium from the ores of the Uchkuduk and Sugraly deposits confirmed the potential possibility of a significant increase in the extraction of uranium by electrophotoactivated percarbonate solutions relative to aqueous solutions of sodium and ammonium carbonate. When leaching with carbonate solutions without an additional oxidizing agent, the extraction of uranium from the Sugraly deposit ore sample was 52 and 59 % (sodium carbonate and ammonium carbonate). The use of hydrogen peroxide as an oxidizing agent made it possible to achieve 87-88 % extraction into pregnant solutions in 21 days without pre-oxidation. The performed studies confirm the processing capability of extracting uranium and molybdenum by percolation leaching in columns and borehole leaching.
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Date submitted2022-02-22
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Date accepted2022-05-11
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Date published2022-11-03
Scientific substantiation and development of innovative processes for the extraction of zirconium and rare earth elements in the deep and comprehensive treatment of eudialyte concentrate
- Authors:
- Valentin A. Chanturiya
Based on a package of modern analysis methods, the influence of various acids and energy effects on the morphology, elemental composition, structural and chemical transformations of the mineral surface, and the efficiency of eudialyte concentrate leaching was studied. The mechanism and the optimal conditions and specific features of the destruction of eudialyte and rock minerals and the extraction of zirconium and REE under the influence of various acids, powerful nanosecond pulses, dielectric barrier discharge, electrochemical processing, mechanochemical activation and ultrasound were revealed. The mechanism of formation and the optimal conditions for the dispersion of silica gel, depending on the methods and parameters of energy effects, was theoretically and experimentally substantiated. A combined three-stage circuit of nitric acid leaching of eudialyte concentrate with ultrasonic treatment of the suspension, providing 97.1 % extraction of zirconium and 94.5 % REE, were scientifically substantiated and tested. The conditions for the selective deposition of zirconium and REE were theoretically and experimentally substantiated.
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Date submitted2020-06-10
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Date accepted2020-11-19
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Date published2021-04-26
Influence of jarosite precipitation on iron balance in heap bioleaching at Monywa copper mine
Ferric iron is an important oxidant in sulfide ore bioleaching. However, recirculating leach liquors leads to excess iron accumulation, which interferes with leaching kinetics and downstream metal recovery. We developed a method for controlling iron precipitation as jarosite to reduce excess iron in heap bioleaching at Monywa copper mine. Jarosite precipitation was first simulated and then confirmed using batch column tests. From the simulations, the minimum pH values for precipitation of potassium jarosite, hydronium jarosite, and natrojarosite at 25 °C are 1.4, 1.6, and 2.7, respectively; the minimum concentrations of potassium, sulfate, ferric, and sodium ions are 1 mM, 0.54, 1.1, and 3.2 M, respectively, at 25 °C and pH 1.23. Column tests indicate that potassium jarosite precipitation is preferential over natrojarosite. Moreover, decreased acidity (from 12 to 8 g/L), increased temperature (from 30 to 60 °C), and increased potassium ion concentration (from 0 to 5 g/L) increase jarosite precipitation efficiency by 10, 5, and 6 times, respectively. Jarosite precipitation is optimized by increasing the irrigating solution pH to 1.6. This approach is expected to reduce the operating cost of heap bioleaching by minimizing the chemicals needed for neutralization, avoiding the need for tailing pond construction, and increasing copper recovery.
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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 submitted2019-05-07
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Date accepted2019-07-25
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Date published2019-10-23
Intensification of Bacterial-Chemical Leaching of Nickel, Copper and Cobalt from Sulfide Ores Using Microwave Radiation
- Authors:
- A. V. Kioresku
Currently, Russia and other countries display a steady tendency to decrease the amount of high grade and free- milling ore reserves. In this regard, the attention is being paid to the technology of bacterial-chemical leaching (BCL), which, unlike traditional pyrometallurgical enrichment methods, is well applicable for processing low-grade mineral raw materials. However, this technology has a significant drawback, which is the inability of microorganisms to create sufficiently aggressive conditions for the effective destruction of mineral complexes, which negatively affects the duration of the processes. The article presents the results of an experiment, the purpose of which was to study the multiple short-term effects of microwave radiation on the efficiency of extraction of nickel, copper, and cobalt in the process of bacterial-chemical leaching of sulfide ore. A microwave oven with a power of 900 W and a radiation frequency of 2.45 GHz was used as a source of microwave radiation. Irradiation was carried out every day throughout the experiment. The exposure time was 5 and 10 s; the flux density was 0.7 W/cm 2 . It was found that for all the studied microwave irradiation modes, a significant increase in the efficiency of biomass accumulation and the oxidizing ability of the medium was observed in comparison with the control that was not exposed to microwave radiation. Irradiation for 5 s twice a day increased the reduction of nickel by 16 %, cobalt by 15 % and copper by 6 %. The results of the study allow us to assess the prospects for the application of new biotechnology methods in the industrial practice of ore processing with an improvement in qualityindicators.
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Date submitted2019-04-28
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Date accepted2019-06-28
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Date published2019-10-23
Determination of Optimal Fluorine Leaching Parameters from the Coal Part of the Waste Lining of Dismantled Electrolytic Cells for Aluminum Production
- Authors:
- N. V. Nemchinova
- A. A. Tyutrin
- V. V. Somov
When aluminum is obtained by electrolysis of cryolite-alumina melts when the baths are sent for capital repairs, a solid technogenic product is formed – waste lining of electrolytic cells (WLEC). The volume of formation of WLEC is 30-50 kg per 1 ton of aluminum. Currently, it is mainly stored at landfills near industrial enterprises, causing harm to the environment. However, this technogenic raw material contains valuable components (fluorine, aluminum, sodium) that can be extracted to produce fluoride salts, which are in demand during the electrolytic production of aluminum. The objects of research were samples of the coal part of the waste lining of dismantled S-8BM (E) type electrolytic cells of «RUSAL Krasnoyarsk» JSC (Krasnoyarsk) of RUSAL company. According to the X-ray experiment diffraction analysis (using a Bruker D8 ADVANCE diffractometer) of the phase composition of the samples, it was found that the main fluorine-containing compounds are cryolite, chiolite, sodium and calcium fluorides. The total fluorine content in the studied samples averaged 13.1 %. We conducted studies on the leaching of fluorine from WLEC with a solution of caustic alkali (NaOH concentration – 17.5 g/dm 3 ). The process was carried out in a mechanically agitated reactor using a BIOSAN MM-1000 top drive laboratory stirrer with a two-blade nozzle. By the method of mathematical planning of a three-factor experiment, the mutual influence of three leaching conditions on the optimization parameter was established – the extraction of fluorine in solution (in percent). The maximum recovery of fluorine from WLEC to the leach solution averaged 86.4 % and was achieved with the following indicators:processtemperature–95 ° C, the ratio ofliquidtosolidphase–9:1,duration– 210 min.
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Date submitted2018-09-02
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Date accepted2018-10-28
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Date published2019-02-22
Factors affecting bacterial and chemical processes of sulphide ores processing
- Authors:
- T. S. Khainasova
Extraction of valuable components from sulphide ores using microorganisms is a recognized biotechnological method, combining several advantages over traditional methods of mineral processing. This paper presents the main factors affecting the bacterial-chemical leaching and methods of leaching with the participation of microorganisms. Some physical-chemical (temperature, pH, oxygen, carbon dioxide, nutrients, metals and other chemical elements) and microbial (cell count and microflora activity) properties are given, either directly or indirectly (suppressing or contributing to the growth and oxidative capacity of microorganisms) affecting the kinetics of the process. The paper discusses the characteristics of the mineral substrate, including galvanic interaction of sulfide minerals and the formation of passivating layers on the surface of the ore during oxidation, emphasizing the importance of the electrochemical interaction of the components of the leaching system. Bioleaching is a complex process, which is a combination of mainly chemical reactions mediated by the microbial component, therefore, to improve the kinetics, it is necessary to consider, monitor and regulate the listed range of factors.
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Date submitted2018-01-06
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Date accepted2018-02-26
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Date published2018-06-22
Extraction of platinum metals during procssing of chromium ores from dunnite deposits
- Authors:
- G. V. Petrov
- Ya. M. Shneerson
- Yu. V. Andreev
Currently, the main raw materials sources of platinum group metals in Russia are complex sulfide copper-nickel ores of the Taimyr region and placer deposits. However, in view of the inevitable loss of platinum metals during the metallurgical processing of initial ores and the deterioration of the quality of ore raw materials, along with a decrease in the share of platinum mining from placers, there is a need to look for new non-traditional sources of platinum group metals. Dunnites of the Middle Urals are promising platinum-bearing raw materials. The use of the gravitational-magnetic processing of chromium ores of dunnite deposits makes it possible to identify a magnetic platinum-bearing concentrate with a high content of magnetite and platinum-iron alloys, they can be refined using chemical-metallurgical methods. This article presents the results of research of identifying peculiarities of technological behavior of chromium, iron and noble metals during mechanical processing of ledge chromium ore. The kinetic regularities of the sulfuric acid decomposition of magnetite are determined. Optimum technological parameters of sulfuric acid leaching of iron from magnetic products of chromium ore dressing are established. Based on the conducted studies, the PDF and PID for the complex processing of chromium ores of dunnite deposits is proposed, which ensures the production of a rich platinum-bearing concentrate and a high-quality chromite concentrate that meets the requirements of chemical production.
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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 submitted2015-07-20
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Date accepted2015-09-26
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Date published2016-02-24
Prospects of biotechnologies application in metallurgy and enrichment
- Authors:
- N. M. Telyakov
- A. A. Darin
- V. A. Luganov
In recent years, application of biotechnologies in enrichment processes and processing of metal-containing ores has gained broad development, considering essential advantages of these technologies from the point of view of economic efficiency and ecological safety. Processes with the application the hemolitotrofnykh of acidophile microorganisms of Acidithiobacillus ferrooxidans, At. thiooxidans, Leptospirillum ferrooxidans and others, are of great interest. This article is devoted to the problem of biocultures application for efficiency improvement of the ore pretreatment technology and extraction of valuable components from metal-containing crude ore. The analysis of the biotechnologies and microorganisms applied at domestic and foreign enterprises is given, alongside with the theoretical bases of ore bioprocessing, research results of oxide and sulphidic metal-containing ores processing technology development, with the application of microorganisms and research results of the mechanism of destructive impact of a certain type bacteria on siliceous ores.
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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 submitted2010-07-20
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Date accepted2010-09-01
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Date published2011-03-21
Experimental and theoretical studies and justification of geotechnology of stock pile formation from pelletized gold-bearing ores in order to enhance its filtration properties
- Authors:
- S. B. Tataurov
Optimal parameters of geotechnology of stock pile formation from pelletized gold-bearing ores were established basing on experimental and theoretical studies in order to enhance its filtration properties. In particular, exponential dependence was established of permeability coefficient on the stock pile height and the ultimate strength of the pelletized ore, its bulk weight and content of coarse particles +2 mmin combination with sandy-loamy and loamy fine grained soil. Without account of this data loss of gold within the stock pile can increase over 2 or 3 times. Basing on the results obtained application of the combined geothechnology of heap leaching of gold-bearing clayey materials of natural and man-made origin was justified.
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Date submitted2009-08-06
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Date accepted2009-10-10
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Date published2010-02-01
Allocation of tellurium from difficult on structure of sulfuric acid solutions
- Authors:
- S. B. Fokina
As the main source of reception of tellurium serve electrolytic copper refinery slimes. In the conditions of manufacture expansion and transition on technology decopperizing slimes by pressure leaching O 2 -H 2 SO 4 media, the solution (decopperized product) becomes the basic concentrator of tellurium. Extraction of tellurium from a decopperized (pressure-leached) liquid products is considered. The method allows to raise percent of extraction of tellurium from initial raw materials and to enrich pressure-leached solid product with precious metals.