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One of the potential sources of alumina and mesoporous silica is the coal-fired thermal plants waste known as the coal fly ash (CFA). The studies of the alumina extraction from CFA are often focused on the preliminary desilication, but the efficiency of the alkali desilication is low due to formation of the desilication product—Na6[Al6Si6O24]·Na2X (DSP). This research is focused on the possibility of CFA desilication without formation of DSP using a leaching process with higher liquid to solid ratios (L/S) and alkali concentrations. The experimental data were analyzed using an artificial neural network (ANN) machine learning method and a shrinking core model (SCM). The investigation of the CFA morphology, chemical and phase composition before and after leaching were carried out by scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), inductively coupled plasma optical emission spectrometry (ICP-OES) and X-ray diffraction (XRD). The present work shows that it is possible to avoid formation of DSP if using the L/S ratio >20 and concentration of Na2O—400 g/L during CFA leaching. The kinetics analysis by SCM showed that the process is limited by the surface chemical reaction at T 100 °C, respectively. The SEM images of the solid residue after NaOH leaching under conditions that prevent the DSP formation show mullite particles with an acicular structure.
Andrei Shoppert; Dmitry Valeev; Irina Loginova; Leonid Chaikin. Complete Extraction of Amorphous Aluminosilicate from Coal Fly Ash by Alkali Leaching under Atmospheric Pressure. Metals 2020, 10, 1684 .
AMA StyleAndrei Shoppert, Dmitry Valeev, Irina Loginova, Leonid Chaikin. Complete Extraction of Amorphous Aluminosilicate from Coal Fly Ash by Alkali Leaching under Atmospheric Pressure. Metals. 2020; 10 (12):1684.
Chicago/Turabian StyleAndrei Shoppert; Dmitry Valeev; Irina Loginova; Leonid Chaikin. 2020. "Complete Extraction of Amorphous Aluminosilicate from Coal Fly Ash by Alkali Leaching under Atmospheric Pressure." Metals 10, no. 12: 1684.
The main sulphide minerals that serve as gold carriers in low-grade raw materials are pyrite and arsenopyrite. Traditional methods of processing such refractory raw materials rely on high-pressure or pyrometallurgical oxidisation, which destroys the crystal lattice of sulphides and releases gold particles. An alternative method of oxidation is leaching with nitric acid. The study examined the kinetics and oxidation mechanism of the natural mineral arsenopyrite in nitric acid media, along with the effect of pyrite on the kinetic characteristics of dissolution. Using the shrinking core model (SCM), it was shown that during the first 5 min of the process, the kinetic of the reaction is controlled by the chemical reaction. Further in the course of the process, the mode changes, which is confirmed by the new shrinking core model. During the period from 5 to 60 min the model was fitted according to diffusion through a product layer and interfacial transfer. The addition of Fe(III) ions and an increase in the concentration of nitric acid have a similar effect on the nitric acid leaching of arsenopyrite, which is associated with an increase in the oxidation potential of the system. The influence of pyrite on the leaching of arsenopyrite is probably associated with its catalytic action in the early stage of the process, which is due to the role of an alternative surface for the reduction of nitrate ions in electrochemical contact with arsenopyrite. The difference in the mechanisms of arsenopyrite oxidation in the presence of Fe(III) ions and pyrite was confirmed by the SEM-EDX analysis.
Denis Rogozhnikov; Kirill Karimov; Andrei Shoppert; Oleg Dizer; Stanislav Naboichenko. Kinetics and mechanism of arsenopyrite leaching in nitric acid solutions in the presence of pyrite and Fe(III) ions. Hydrometallurgy 2020, 199, 105525 .
AMA StyleDenis Rogozhnikov, Kirill Karimov, Andrei Shoppert, Oleg Dizer, Stanislav Naboichenko. Kinetics and mechanism of arsenopyrite leaching in nitric acid solutions in the presence of pyrite and Fe(III) ions. Hydrometallurgy. 2020; 199 ():105525.
Chicago/Turabian StyleDenis Rogozhnikov; Kirill Karimov; Andrei Shoppert; Oleg Dizer; Stanislav Naboichenko. 2020. "Kinetics and mechanism of arsenopyrite leaching in nitric acid solutions in the presence of pyrite and Fe(III) ions." Hydrometallurgy 199, no. : 105525.
The limited availability of high-quality bauxite and, at the same time, the formation of a considerable amount of harmful red mud (bauxite residue) causes to develop cost-effective technologies for bauxite processing. Selective separation of iron from red mud allows solving this problem and producing marketable products in the form of pigment-quality magnetite. In this context, the possibility of the pigment-quality magnetite obtaining by the interaction of freshly precipitated iron hydroxide (III) of the sintering process red mud with ferrous iron ions in an alkaline medium is studied. It was found that the optimal parameters of the process are: temperature = 90°C; duration = 4 hours; a ratio of ferrous iron to stoichiometric quantity = 70 %. The yield of the magnetic concentrate under optimal conditions was 69.3 %, and the content of magnetite in concentrate was 47.7 %.
Andrei Shoppert; I V Loginova; J A Napol’Skikh. Obtaining of Pigment-Quality Magnetite from Sintering Process Red Mud. IOP Conference Series: Materials Science and Engineering 2020, 969, 012056 .
AMA StyleAndrei Shoppert, I V Loginova, J A Napol’Skikh. Obtaining of Pigment-Quality Magnetite from Sintering Process Red Mud. IOP Conference Series: Materials Science and Engineering. 2020; 969 (1):012056.
Chicago/Turabian StyleAndrei Shoppert; I V Loginova; J A Napol’Skikh. 2020. "Obtaining of Pigment-Quality Magnetite from Sintering Process Red Mud." IOP Conference Series: Materials Science and Engineering 969, no. 1: 012056.
In the present paper a novel process of the coal ash treatment was developed and analyzed: a high-pressure autoclave HCl leaching of the coal bottom and fly ash from an Omsk coal-fired power plant. This process was applied to extract aluminum from the coal ash into a chloride solution, which can further be used as a coagulant for water treatment. The Al extraction efficiency in this process can reach over 90 % at certain process parameters discussed in the present study. Kinetics of the leaching process were evaluated using different kinetic (e.g. shrinking core) models. A semi-empirical equation was proposed for description of the kinetics of the leaching process as a function of the HCl concentration, solid-to-liquid ratio and temperature. Different mechanisms of the leaching process were also discussed and proposed. Water treatment by the obtained Al-chloride showed good results compared to an industrial coagulant; the treated water parameters were within the limits recommended by the World Health Organization for drinkable water.
Dmitry Valeev; Irina Kunilova; Andrei Shoppert; Cristian Salazar-Concha; Alex Kondratiev. High-pressure HCl leaching of coal ash to extract Al into a chloride solution with further use as a coagulant for water treatment. Journal of Cleaner Production 2020, 276, 123206 .
AMA StyleDmitry Valeev, Irina Kunilova, Andrei Shoppert, Cristian Salazar-Concha, Alex Kondratiev. High-pressure HCl leaching of coal ash to extract Al into a chloride solution with further use as a coagulant for water treatment. Journal of Cleaner Production. 2020; 276 ():123206.
Chicago/Turabian StyleDmitry Valeev; Irina Kunilova; Andrei Shoppert; Cristian Salazar-Concha; Alex Kondratiev. 2020. "High-pressure HCl leaching of coal ash to extract Al into a chloride solution with further use as a coagulant for water treatment." Journal of Cleaner Production 276, no. : 123206.
Ammonia leaching is a promising method for processing low-grade copper ores, especially those containing large amounts of oxidized copper. In this paper, we study the effect of Si-containing minerals on the kinetics of Cu and Ag leaching from low-grade copper concentrates. The results of experiments on the pressure leaching of the initial copper concentrate in an ammonium/ammonium-carbonate solution with oxygen as an oxidizing agent are in good agreement with the shrinking core model in the intra-diffusion mode: in this case, the activation energies were 53.50 kJ/mol for Cu and 90.35 kJ/mol for Ag. Energy-dispersive X-ray spectroscopy analysis (EDX) analysis showed that reagent diffusion to Cu-bearing minerals can be limited by aluminosilicate minerals of the gangue. The recovery rate for copper and silver increases significantly after a preliminary alkaline desilication of the concentrate, and the new shrinking core model is the most adequate, showing that the process is limited by diffusion through the product layer and interfacial diffusion. The activation energy of the process increases to 86.76 kJ/mol for Cu and 92.15 kJ/mol for Ag. Using the time-to-a-given-fraction method, it has been shown that a high activation energy is required in the later stages of the process, when the most resistant sulfide minerals of copper and silver apparently remain.
Kirill Karimov; Andrei Shoppert; Denis Rogozhnikov; Evgeniy Kuzas; Semen Zakhar’Yan; Stanislav Naboichenko. Effect of Preliminary Alkali Desilication on Ammonia Pressure Leaching of Low-Grade Copper–Silver Concentrate. Metals 2020, 10, 812 .
AMA StyleKirill Karimov, Andrei Shoppert, Denis Rogozhnikov, Evgeniy Kuzas, Semen Zakhar’Yan, Stanislav Naboichenko. Effect of Preliminary Alkali Desilication on Ammonia Pressure Leaching of Low-Grade Copper–Silver Concentrate. Metals. 2020; 10 (6):812.
Chicago/Turabian StyleKirill Karimov; Andrei Shoppert; Denis Rogozhnikov; Evgeniy Kuzas; Semen Zakhar’Yan; Stanislav Naboichenko. 2020. "Effect of Preliminary Alkali Desilication on Ammonia Pressure Leaching of Low-Grade Copper–Silver Concentrate." Metals 10, no. 6: 812.
One of the potential sources of rare-earth elements (REE) is the industrial waste known as red mud (bauxite residue), in which the majority of REE from the initial bauxite are concentrated via the Bayer process. Therefore, the studies of the subject, both in Russia and outside, focus almost exclusively on red mud processing. This article looks into the possibility of REE concentration into red mud by leaching an intermediate product of the bauxite sintering process at Russian alumina refineries, namely electrostatic precipitator (ESP) dust. The experimental works were performed by X-ray diffraction (XRD)and electron probe microanalysis (EPMA) of the sinter and sinter dust. The determination of major and rare-earth elements in the sinter from the rotary kilns and in the ESP dust before and after leaching was carried out by X-ray fluorescence (XRF) and plasma mass spectrometry (ICP-MS). The study showed that it is possible to obtain red mud that contains three times more REE than traditional waste red mud after two-stage leaching ESP dust in the water at 95 °C followed by leaching in an alkaline-aluminate liquor at 240 °C. The shrinking core model was used to study the kinetics of leaching of the original ESP dust and water-treated dust in alkaline-aluminate liquor. The study showed the change in the limiting stage of the alkaline leaching process after water treatment, with the activation energy growing from 24.98 to 33.19 kJ/mol.
Leonid Chaikin; Andrei Shoppert; Dmitry Valeev; Irina Loginova; Julia Napol’Skikh. Concentration of Rare Earth Elements (Sc, Y, La, Ce, Nd, Sm) in Bauxite Residue (Red Mud) Obtained by Water and Alkali Leaching of Bauxite Sintering Dust. Minerals 2020, 10, 500 .
AMA StyleLeonid Chaikin, Andrei Shoppert, Dmitry Valeev, Irina Loginova, Julia Napol’Skikh. Concentration of Rare Earth Elements (Sc, Y, La, Ce, Nd, Sm) in Bauxite Residue (Red Mud) Obtained by Water and Alkali Leaching of Bauxite Sintering Dust. Minerals. 2020; 10 (6):500.
Chicago/Turabian StyleLeonid Chaikin; Andrei Shoppert; Dmitry Valeev; Irina Loginova; Julia Napol’Skikh. 2020. "Concentration of Rare Earth Elements (Sc, Y, La, Ce, Nd, Sm) in Bauxite Residue (Red Mud) Obtained by Water and Alkali Leaching of Bauxite Sintering Dust." Minerals 10, no. 6: 500.
Sandy grade alumina is a valuable intermediate material that is mainly produced by the Bayer process and used for manufacturing primary metallic aluminum. Coal fly ash is generated in coal-fired power plants as a by-product of coal combustion that consists of submicron ash particles and is considered to be a potentially hazardous technogenic waste. The present paper demonstrates that the Al-chloride solution obtained by leaching coal fly ash can be further processed to obtain sandy grade alumina, which is essentially suitable for metallic aluminum production. The novel process developed in the present study involves the production of amorphous alumina via the calcination of aluminium chloride hexahydrate obtained by salting-out from acid Al-Cl liquor. Following this, alkaline treatment with further Al2O3 dissolution and recrystallization as Al(OH)3 particles is applied, and a final calcination step is employed to obtain sandy grade alumina with minimum impurities. The process does not require high-pressure equipment and reutilizes the alkaline liquor and gibbsite particles from the Bayer process, which allows the sandy grade alumina production costs to be to significantly reduced. The present article also discusses the main technological parameters of the acid treatment and the amounts of major impurities in the sandy grade alumina obtained by the different (acid and acid-alkali) methods.
Dmitry Valeev; Andrei Shoppert; Alexandra Mikhailova; Alex Kondratiev. Acid and Acid-Alkali Treatment Methods of Al-Chloride Solution Obtained by the Leaching of Coal Fly Ash to Produce Sandy Grade Alumina. Metals 2020, 10, 585 .
AMA StyleDmitry Valeev, Andrei Shoppert, Alexandra Mikhailova, Alex Kondratiev. Acid and Acid-Alkali Treatment Methods of Al-Chloride Solution Obtained by the Leaching of Coal Fly Ash to Produce Sandy Grade Alumina. Metals. 2020; 10 (5):585.
Chicago/Turabian StyleDmitry Valeev; Andrei Shoppert; Alexandra Mikhailova; Alex Kondratiev. 2020. "Acid and Acid-Alkali Treatment Methods of Al-Chloride Solution Obtained by the Leaching of Coal Fly Ash to Produce Sandy Grade Alumina." Metals 10, no. 5: 585.
The overall decrease in the quality of mineral raw materials, combined with the use of arsenic-containing ores, results in large amounts of various intermediate products containing this highly toxic element. The use of hydrometallurgical technologies for these materials is complicated by the formation of multicomponent solutions and the difficulty of separating copper from arsenic. Previously, for the selective separation of As from copper–arsenic intermediates a leaching method in the presence of Cu(II) ions was proposed. This paper describes the investigation of the kinetics of arsenic sulfide-containing materials leaching by copper sulfate solution. The cakes after leaching of arsenic trisulfide with a solution of copper sulfate were described using methods such as X-ray diffraction spectrometry (XRD), X-ray fluorescence spectrometry (XRF), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy analysis (EDS). The effect of temperature (70–90 °C), the initial concentration of CuSO4 (0.23–0.28 M) and the time on the As recovery into the solution was studied. The process temperature has the greatest effect on the kinetics, while an increase in copper concentration from 0.23 to 0.28 M effects an increase in As transfer into solution from 93.2% to 97.8% for 120 min of leaching. However, the shrinking core model that best fits the kinetic data suggests that the process occurs by the intra-diffusion mode with the average activation energy of 44.9 kJ/mol. Using the time-to-a-given-fraction kinetics analysis, it was determined that the leaching mechanism does not change during the reaction. The semi-empirical expression describing the reaction rate under the studied conditions can be written as follows: 1/3ln(1 − X) + [(1 − X) − 1/3 − 1] = 4560000Cu3.61e−44900/RT t.
Kirill A. Karimov; Denis A. Rogozhnikov; Evgeniy A. Kuzas; Andrei A. Shoppert. Leaching Kinetics of Arsenic Sulfide-Containing Materials by Copper Sulfate Solution. Metals 2019, 10, 7 .
AMA StyleKirill A. Karimov, Denis A. Rogozhnikov, Evgeniy A. Kuzas, Andrei A. Shoppert. Leaching Kinetics of Arsenic Sulfide-Containing Materials by Copper Sulfate Solution. Metals. 2019; 10 (1):7.
Chicago/Turabian StyleKirill A. Karimov; Denis A. Rogozhnikov; Evgeniy A. Kuzas; Andrei A. Shoppert. 2019. "Leaching Kinetics of Arsenic Sulfide-Containing Materials by Copper Sulfate Solution." Metals 10, no. 1: 7.
The processing of refractory gold-containing concentrates by hydrometallurgical methods is becoming increasingly important due to the depletion of rich and easily extracted mineral resources, as well as due to the need to reduce harmful emissions from metallurgy, especially given the high content of arsenic in the ores. This paper describes the investigation of the kinetics of HNO3 leaching of sulfide gold-containing concentrates of the Yenisei ridge (Yakutia, Russia). The effect of temperature (70–85 °C), the initial concentration of HNO3 (10–40%) and the content of sulfur in the concentrate (8.22–22.44%) on the iron recovery into the solution was studied. It has been shown that increasing the content of S in the concentrate from 8.22 to 22.44% leads to an average of 45% increase in the iron recovery across the entire range temperatures and concentrations of HNO3 per one hour of leaching. The leaching kinetics of the studied types of concentrates correlates well with the new shrinking core model, which indicates that the reaction is regulated by interfacial diffusion and diffusion through the product layer. Elemental S is found on the surface of the solid leach residue, as confirmed by XRD and SEM/EDS analysis. The apparent activation energy is 60.276 kJ/mol. The semi-empirical expression describing the reaction rate under the studied conditions can be written as follows: 1/3ln(1 − X) + [(1 − X)−1/3 − 1] = 87.811(HNO3)0.837(S)2.948e−60276/RT·t.
Denis A. Rogozhnikov; Andrei A. Shoppert; Oleg Dizer; Kirill A. Karimov; Rostislav E. Rusalev. Leaching Kinetics of Sulfides from Refractory Gold Concentrates by Nitric Acid. Metals 2019, 9, 465 .
AMA StyleDenis A. Rogozhnikov, Andrei A. Shoppert, Oleg Dizer, Kirill A. Karimov, Rostislav E. Rusalev. Leaching Kinetics of Sulfides from Refractory Gold Concentrates by Nitric Acid. Metals. 2019; 9 (4):465.
Chicago/Turabian StyleDenis A. Rogozhnikov; Andrei A. Shoppert; Oleg Dizer; Kirill A. Karimov; Rostislav E. Rusalev. 2019. "Leaching Kinetics of Sulfides from Refractory Gold Concentrates by Nitric Acid." Metals 9, no. 4: 465.
This study investigates the use of red muds as adsorbents for As (V) removal. Red mud is a waste that contains a large amount of iron oxides and hydroxides, which are excellent adsorbents of arsenic, especially those possessing magnetic properties and a large specific surface area. The purpose of the experiments was to study the possibility of obtaining an effective adsorbent by the direct extraction of alumina from bauxite using the caustic alkali fusion method and to compare the arsenic removal effectiveness and other properties of these red muds with industrial samples. Red muds were described using methods such as X-ray diffraction spectrometry (XRD), X-ray fluorescence spectrometry (XRF), SEM, vibrating sample magnetometry (VSM), and the Brunauer–Emmett–Teller (BET) method. The main iron-containing phase of the red muds obtained by fusing bauxite with caustic alkali is maghemite, which has a large specific surface area. The specific surface area of the obtained samples varied in the range of 6.1–54.9 m2/g. Arsenic adsorption experiments were carried out using five different types of red muds: industrial Bayer, industrial sintering, and red mud obtained through bauxite alkali fusion at 300, 500, and 700 °C. The red muds obtained by fusing bauxite with caustic alkali at 300 and 500 °C had the highest effectiveness removing arsenic; their As(V) uptake capacity was over 30 mg/g.
Andrei A. Shoppert; Irina V. Loginova; Denis A. Rogozhnikov; Kirill A. Karimov; Leonid I. Chaikin. Increased As Adsorption on Maghemite-Containing Red Mud Prepared by the Alkali Fusion-Leaching Method. Minerals 2019, 9, 60 .
AMA StyleAndrei A. Shoppert, Irina V. Loginova, Denis A. Rogozhnikov, Kirill A. Karimov, Leonid I. Chaikin. Increased As Adsorption on Maghemite-Containing Red Mud Prepared by the Alkali Fusion-Leaching Method. Minerals. 2019; 9 (1):60.
Chicago/Turabian StyleAndrei A. Shoppert; Irina V. Loginova; Denis A. Rogozhnikov; Kirill A. Karimov; Leonid I. Chaikin. 2019. "Increased As Adsorption on Maghemite-Containing Red Mud Prepared by the Alkali Fusion-Leaching Method." Minerals 9, no. 1: 60.
Modern aluminum electrolysis in cryolite-alumina melts is energy-intensive, inefficient and environmentally hazardous production. Addressing these significant shortcomings, the technology of low-temperature electrolyte is directed. The basis of low-temperature electrolysis is potassium cryolite, which results in high magnitude and rate of dissolution of alumina. Additive of sodium and lithium fluorides provide the necessary conductivity. Experimental investigation of these properties is extremely time consuming. In this work, as a parameter, which will allow to characterize effectively and rapidly the complexing ability of cryolite melts, the ratio of cationic ion power of Al3+ to the total power of the other cations of the melt is proposed. Regression analyses of the known experimental data establish the existence with a high level of reliability (R2=0.966-0.995) of a directly proportional dependence of this parameter on solubility of alumina and electrical conductivity of cryolite melts.
V.A. Lebedev; Andrey A. Shoppert. Efficient Assessment of Physico-Chemical Properties of the Cryolite Melts for Research on the Improvement of Low-Temperature Aluminum Electrolysis. Solid State Phenomena 2018, 284, 839 -844.
AMA StyleV.A. Lebedev, Andrey A. Shoppert. Efficient Assessment of Physico-Chemical Properties of the Cryolite Melts for Research on the Improvement of Low-Temperature Aluminum Electrolysis. Solid State Phenomena. 2018; 284 ():839-844.
Chicago/Turabian StyleV.A. Lebedev; Andrey A. Shoppert. 2018. "Efficient Assessment of Physico-Chemical Properties of the Cryolite Melts for Research on the Improvement of Low-Temperature Aluminum Electrolysis." Solid State Phenomena 284, no. : 839-844.
Low grade copper concentrate, composed mainly of plagioclase, quartz, pyrite, chlorite, chalcopyrite, glauconite, is a promising source for the future recovery of copper and other valuable components which processing by existing methods is not economical. An alkali fusion-leaching method followed by acid leaching for extraction of copper, aluminum, silica, iron and silver from such low-grade copper concentrate was explored in this research. The samples were characterized by using wet chemical analysis and X-ray diffraction. An alkali-fusing-leaching method for processing of low-grade copper concentrate allows to extract in a solution of 62% Si, 70% Fe, 95% Ag, 97% Al and 98% of Cu with the following optimal parameters: NaOH/concentrate mass ratio = 175%, fusion temperature = 375 °C, the fusion time = 90 min. The proposed method is suitable for the comprehensive processing of the low-grade copper concentrate.
Andrey A. Shoppert; L.M. Karimova; D.V. Zakharyan. Novel Method for Comprehensive Processing of Low-Grade Copper Concentrate. Solid State Phenomena 2018, 284, 856 -862.
AMA StyleAndrey A. Shoppert, L.M. Karimova, D.V. Zakharyan. Novel Method for Comprehensive Processing of Low-Grade Copper Concentrate. Solid State Phenomena. 2018; 284 ():856-862.
Chicago/Turabian StyleAndrey A. Shoppert; L.M. Karimova; D.V. Zakharyan. 2018. "Novel Method for Comprehensive Processing of Low-Grade Copper Concentrate." Solid State Phenomena 284, no. : 856-862.
I. V. Loginova; Andrey Shoppert; E. Yu. Kryuchkov. Kinetics investigation and optimal parameters of alumina extraction during the Middle Timan bauxites leaching. Tsvetnye Metally 2018, 63 -68.
AMA StyleI. V. Loginova, Andrey Shoppert, E. Yu. Kryuchkov. Kinetics investigation and optimal parameters of alumina extraction during the Middle Timan bauxites leaching. Tsvetnye Metally. 2018; ():63-68.
Chicago/Turabian StyleI. V. Loginova; Andrey Shoppert; E. Yu. Kryuchkov. 2018. "Kinetics investigation and optimal parameters of alumina extraction during the Middle Timan bauxites leaching." Tsvetnye Metally , no. : 63-68.
In this study the extraction of titanium from bauxite residue (red mud) with 2 step acid leaching was proposed. In the first step red mud was leached with diluted hydrochloric acid under stirring to remove the soluble Ca, Na, Al, Si and K at 25 0C and pH=3 for 1 hour. The content of iron and titanium in the solid residue increased to 57.7% and 6.4%, respectively. The factors influencing sulfuric acid leaching of the solid residue in the second stage were examined by factorial design. The optimal iron and titanium extraction efficiency was obtained after leaching at 50 oC and L:S ration 20:1 for 90 min when 80 g/L sulfuric acid was used. The titanium oxide content in the concentrate obtained under the optimum conditions amounted to 46.7%. The maximum recovery of titanium in the sulfuric acid solution has not exceeded 6%.
A.A. Shoppert; I.V. Loginova. Red Mud as an Additional Source of Titanium Raw Materials. KnE Materials Science 2017, 2, 150 .
AMA StyleA.A. Shoppert, I.V. Loginova. Red Mud as an Additional Source of Titanium Raw Materials. KnE Materials Science. 2017; 2 (2):150.
Chicago/Turabian StyleA.A. Shoppert; I.V. Loginova. 2017. "Red Mud as an Additional Source of Titanium Raw Materials." KnE Materials Science 2, no. 2: 150.
Fly ash, composed of mullite, hematite, amorphous silica and quartz, is a promising source for the recovery of alumina and silica. Desilication with help of NaOH and alkali fusion-leaching method and utilization of alumina and silica in the fly ash for preparation of sodalite and silica white were explored in this research. The samples were characterized by using wet chemical analysis and X-ray diffraction. The optimal extraction of SiO2 from Reftinskaya power plant fly ash was 46.2% with leaching at 95 oC for 3 h. Sodalite was synthesized at 200 °C for 1 h followed water leaching at 95 °C for 1 h. Silica white with specific surface area 180-220 m2/g was prepared by carbonation of the Na2SiO3 solution at 40 oC for 90-120 min. The as-prepared silica has a purity of 98,8%.The proposed method is suitable for the comprehensive utilization of the fly ash.
A.A. Shoppert; I.V. Loginova; L.I. Chaikin; D.A. Rogozhnikov. Alkali Fusion-Leaching Method For Comprehensive Processing Of Fly Ash. KnE Materials Science 2017, 2, 89 .
AMA StyleA.A. Shoppert, I.V. Loginova, L.I. Chaikin, D.A. Rogozhnikov. Alkali Fusion-Leaching Method For Comprehensive Processing Of Fly Ash. KnE Materials Science. 2017; 2 (2):89.
Chicago/Turabian StyleA.A. Shoppert; I.V. Loginova; L.I. Chaikin; D.A. Rogozhnikov. 2017. "Alkali Fusion-Leaching Method For Comprehensive Processing Of Fly Ash." KnE Materials Science 2, no. 2: 89.
The effect of chemical treatment of industrially produced aluminum hydroxide on its seed activity during decomposition and capacity for agglomeration is studied with the aim of preparing sandy alumina in Ural aluminum plants. It is shown that the most suitable reagent for activating aluminum hydroxide is aluminate solution. After two hours of treatment of seed aluminum hydroxide in an alkaline solution at 90°C, the degree of aluminate solution decomposition increases by 4–5%. It is revealed that with the use of production aluminum hydroxide activated in aluminate solution during agglomeration it is possible to reduce the content within it of fraction –45 μm from 25 to 5%.
A. A. Shoppert; I. V. Loginova. Surface Activation of Industrial Aluminum Hydroxide for Preparing Sandy Alumina. Metallurgist 2016, 60, 871 -876.
AMA StyleA. A. Shoppert, I. V. Loginova. Surface Activation of Industrial Aluminum Hydroxide for Preparing Sandy Alumina. Metallurgist. 2016; 60 (7-8):871-876.
Chicago/Turabian StyleA. A. Shoppert; I. V. Loginova. 2016. "Surface Activation of Industrial Aluminum Hydroxide for Preparing Sandy Alumina." Metallurgist 60, no. 7-8: 871-876.
An integrated technology is proposed for processing diaspore-boehmite bauxites and extracting their useful components. It is established that sintering bauxite with a caustic alkali increases the quantities of rare-earth metals that are recovered. Experiments showed that the sintering of bauxite with a caustic alkali must be done with no more than 10–15% moisture in the charge at the optimum temperature of 200°C. Leaching of the sinter cake with water or a dilute aluminate solution forms high-iron red mud with low concentrations of alkali and alkaline-earth metals. Leaching the mud with a dilute inorganic acid makes it possible to extract up to 90% of the rare-earth metals, including scandium oxide.
I. V. Loginova; A. A. Shoppert; L. I. Chaikin. Extraction of Rare-Earth Metals During the Systematic Processing of Diaspore-Boehmite Bauxites. Metallurgist 2016, 60, 198 -203.
AMA StyleI. V. Loginova, A. A. Shoppert, L. I. Chaikin. Extraction of Rare-Earth Metals During the Systematic Processing of Diaspore-Boehmite Bauxites. Metallurgist. 2016; 60 (1):198-203.
Chicago/Turabian StyleI. V. Loginova; A. A. Shoppert; L. I. Chaikin. 2016. "Extraction of Rare-Earth Metals During the Systematic Processing of Diaspore-Boehmite Bauxites." Metallurgist 60, no. 1: 198-203.
I. V. Loginova; A. A. Shoppert; A. V. Kyrchikov; S. F. Ordon; I. S. Medyankina. Using iron-rich red mud from alumina production at steel plants. Steel in Translation 2016, 46, 74 -77.
AMA StyleI. V. Loginova, A. A. Shoppert, A. V. Kyrchikov, S. F. Ordon, I. S. Medyankina. Using iron-rich red mud from alumina production at steel plants. Steel in Translation. 2016; 46 (1):74-77.
Chicago/Turabian StyleI. V. Loginova; A. A. Shoppert; A. V. Kyrchikov; S. F. Ordon; I. S. Medyankina. 2016. "Using iron-rich red mud from alumina production at steel plants." Steel in Translation 46, no. 1: 74-77.
Results are given for studying combined leaching of bauxite, bauxite cake, and sintering section electrostatic precipitator dust. Experiments are performed within the following limiting conditions: temperature 220–260°C, leaching time 30–90 min, return solution concentration 315–280 g/dm3 Na2Oc. It is proven that alumina extraction into solution with combined leaching of bauxite, cake, and electrostatic precipitator dust is higher than with standard bauxite leaching by the Bayer process. A favorable effect is achieved due to forming alumino-ferruginous hydrogarnets during leaching. An increase in leaching temperature makes it possible to improve alumina leaching under stable uniform conditions.
I. V. Loginova; A. A. Shoppert; L. I. Chaikin. Effect of Adding Sintering Furnace Electrostatic Precipitator Dust on Combined Leaching of Bauxites and Cakes. Metallurgist 2015, 59, 698 -704.
AMA StyleI. V. Loginova, A. A. Shoppert, L. I. Chaikin. Effect of Adding Sintering Furnace Electrostatic Precipitator Dust on Combined Leaching of Bauxites and Cakes. Metallurgist. 2015; 59 (7-8):698-704.
Chicago/Turabian StyleI. V. Loginova; A. A. Shoppert; L. I. Chaikin. 2015. "Effect of Adding Sintering Furnace Electrostatic Precipitator Dust on Combined Leaching of Bauxites and Cakes." Metallurgist 59, no. 7-8: 698-704.
The preparation of active aluminum hydroxide from the alkali-aluminate solution of the Bayer process with the help of aluminum salt is investigated. For this purpose the ability of the nonuniform crystal growth at low temperatures and without stirring was used. Finally, a precipitate with a high specific surface, which is easily soluble in acids and alkalis, is formed. The activation energy of obtaining active aluminum hydroxide is determined experimentally. This energy constituted 155.4 kJ/mol, which points to the kinetic process mode despite the absence of stirring. The possibility of applying active aluminum hydroxide as a seed for the production of well-crystallized finely dispersed aluminum hydroxide powder, which can be used to fabricate aluminum oxide for nonmetallurgical applications is shown.
I. V. Loginova; A. A. Shoppert. Preparation of active aluminum hydroxide and its use for production of finely dispersed alumina. Russian Journal of Non-Ferrous Metals 2014, 55, 234 -237.
AMA StyleI. V. Loginova, A. A. Shoppert. Preparation of active aluminum hydroxide and its use for production of finely dispersed alumina. Russian Journal of Non-Ferrous Metals. 2014; 55 (3):234-237.
Chicago/Turabian StyleI. V. Loginova; A. A. Shoppert. 2014. "Preparation of active aluminum hydroxide and its use for production of finely dispersed alumina." Russian Journal of Non-Ferrous Metals 55, no. 3: 234-237.