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Alex Kondratiev - One of the best experts on this subject based on the ideXlab platform.
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complex utilisation of ekibastuz brown coal fly ash iron carbon separation and Aluminum Extraction
Journal of Cleaner Production, 2019Co-Authors: Dmitry Valeev, Irina V Kunilova, A Alpatov, A B Mikhailova, M Goldberg, Alex KondratievAbstract:Abstract Fly ash landfills that accumulate a by-product of coal combustion and gasification represent a permanent threat to the surrounding environment due to many factors (air and water pollution, soil contamination, wildlife poisoning, etc). Moreover, disposed coal fly ash may contain significant amounts of valuable elements that are not extracted and potentially wasted. To improve the above situation, a combined ash treatment process was developed for utilisation of the coal fly ash waste from coal-fired power stations. The ash treatment includes three stages: 1) magnetic separation of an iron-containing fraction, 2) carbon separation by floatation, and 3) Extraction of Aluminum by the autoclave hydrochloric acid leaching. The lab-scale results of the ash treatment applied to the Ekibastuz brown coal fly ash from the Omsk power stations (Russia) were presented and discussed. The XRD analysis showed that the fly ash consists primarily of quartz, mullite and magnetite. It was found that the magnetic fraction separated at the first stage is enriched in magnetite (over 20 wt %), the carbon content in the concentrate after flotation increases to 27 wt %, and 90–95% of Aluminum can be extracted during the autoclave acid leaching. The SEM analysis showed that the magnetite phase is grown on the surface of alumosilicate spheres as ∼1 μm cubic crystals. The effect of the autoclave temperature and exposure time on the Al Extraction efficiency was also investigated and analysed in the present paper. The optimal autoclave temperature and exposure time were found to achieve the maximum Al Extraction efficiency. It was also found by the SEM microanalysis that further Extraction of Aluminum is not economically feasible since the remaining Al is evenly surrounded by SiO2 in the fly ash particles.
Dmitry Valeev - One of the best experts on this subject based on the ideXlab platform.
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complex utilisation of ekibastuz brown coal fly ash iron carbon separation and Aluminum Extraction
Journal of Cleaner Production, 2019Co-Authors: Dmitry Valeev, Irina V Kunilova, A Alpatov, A B Mikhailova, M Goldberg, Alex KondratievAbstract:Abstract Fly ash landfills that accumulate a by-product of coal combustion and gasification represent a permanent threat to the surrounding environment due to many factors (air and water pollution, soil contamination, wildlife poisoning, etc). Moreover, disposed coal fly ash may contain significant amounts of valuable elements that are not extracted and potentially wasted. To improve the above situation, a combined ash treatment process was developed for utilisation of the coal fly ash waste from coal-fired power stations. The ash treatment includes three stages: 1) magnetic separation of an iron-containing fraction, 2) carbon separation by floatation, and 3) Extraction of Aluminum by the autoclave hydrochloric acid leaching. The lab-scale results of the ash treatment applied to the Ekibastuz brown coal fly ash from the Omsk power stations (Russia) were presented and discussed. The XRD analysis showed that the fly ash consists primarily of quartz, mullite and magnetite. It was found that the magnetic fraction separated at the first stage is enriched in magnetite (over 20 wt %), the carbon content in the concentrate after flotation increases to 27 wt %, and 90–95% of Aluminum can be extracted during the autoclave acid leaching. The SEM analysis showed that the magnetite phase is grown on the surface of alumosilicate spheres as ∼1 μm cubic crystals. The effect of the autoclave temperature and exposure time on the Al Extraction efficiency was also investigated and analysed in the present paper. The optimal autoclave temperature and exposure time were found to achieve the maximum Al Extraction efficiency. It was also found by the SEM microanalysis that further Extraction of Aluminum is not economically feasible since the remaining Al is evenly surrounded by SiO2 in the fly ash particles.
Bernd Friedrich - One of the best experts on this subject based on the ideXlab platform.
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phase characterization and thermochemical simulation of landfilled bauxite residue red mud in different alkaline processes optimized for Aluminum recovery
Hydrometallurgy, 2018Co-Authors: Frank Kausen, Bernd FriedrichAbstract:Abstract In coherent studies three different processes of hydrometallurgical, alkaline Extraction of Aluminum from bauxite residue (BR) are examined and benchmarked regarding their efficiency on Aluminum recovery. The employed processes include a direct second caustic pressure leaching, a caustic pressure leaching of the slag produced by reductive smelting of BR with simultaneous pig iron recovery (adapted “Pedersen-process”) and leaching of BR after a sintering stage with sodium carbonate and further additives including lime and coke. In order to ensure a direct comparability, all experiments are conducted using the same homogenized BR from an old industrial landfill. After detailed characterization of the used BR using XRF chemical analysis, XRD phase analysis, SEM optical analysis and Qemscan® phase analysis/distribution, occurring phase formations during the employed processes are also calculated and predicted by FactSage® simulation software. The actual phase formation and leachability of the formed Aluminum phases are verified during experiments and a special focus is set on the dissolution of silicon as major impurity in all processes. It can be shown that Aluminum Extraction efficiencies of 90% are still possible but interlinked with massive silicon dissolution due to the almost complete dissolution of Aluminum silicates.
Weidler, Peter G - One of the best experts on this subject based on the ideXlab platform.
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Increasing the efficiency of silicon and Aluminum Extraction from Volclay by a water iteration treatment for the synthesis of MCM-41 nanomaterials
'Elsevier BV', 2026Co-Authors: Adjdir Mehdi, Bendeddouche, Choukry K, Benhaoua Hadj, Kaid Mhamed, Karmaoui Mohamed, Boudinar Mohamed, Weidler, Peter GAbstract:This work aims to reduce the prices of a wide range of nanomaterials which are unreachable in the industry by using natural sources as silicon and Aluminum precursors. In a previous work, silicon and Aluminum have been extracted from Volclay after applying the alkaline fusion process at 550 8C, and a water treatment of this fused clay by adopting a weight ratio (1:4, fusion mass:H2O) to synthesize Al MCM41 nanomaterials. In this study, the weight ratio of fusion mass:H2O was increased to 1:8 to synthesize a highly structurally ordered MCM41 under the same reaction conditions. The Al MCM41 nanomaterials are investigated by inductively coupled plasma optical emission spectro metry (ICPOES), powder X ray diffraction (XRD), N2 adsorptiondesorption measure ments and scanning electron microscopy (ESEM). As a result, the increase in the weight ratio fusion mass:H2O generates more silica and Aluminum, which allows the formation of wellordered MCM 41 nanomaterials with high pore volume (0.70 cm3/g), high surface area (1044 m2/g), and uniform mesoporous diameter (3.67 nm); as a consequence, the increase in the weight ratio fusion mass:H2O leads to an increase in the mass of Al MCM 41 (9.3 g for 1:8 compared to 5 g for 1:4), whereas the yield of production of mesoporous materials increases to 86%
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Increasing the efficiency of silicon and Aluminum Extraction from Volclay by a water iteration treatment for the synthesis of MCM-41 nanomaterials
'Elsevier BV', 2026Co-Authors: Adjdir Mehdi, Bendeddouche, Choukry K, Benhaoua Hadj, Kaid Mhamed, Karmaoui Mohamed, Boudinar Mohamed, Weidler, Peter GAbstract:This work aims to reduce the prices of a wide range of nanomaterials which are unreachable in the industry by using natural sources as silicon and Aluminum precursors. In a previous work, silicon and Aluminum have been extracted from Volclay after applying the alkaline fusion process at 550 degrees C and a water treatment of this fused clay by adopting a weight ratio (1:4, fusion mass:H2O) to synthesize Al-MCM-41 nanomaterials. In this study, the weight ratio of fusion mass:H2O was increased to 1:8 to synthesize a highly structurally ordered MCM-41 under the same reaction conditions. The Al-MCM-41 nanomaterials are investigated by inductively coupled plasma optical emission spectrometry (ICP-OES), powder X-ray diffraction (XRD), N-2 adsorption-desorption measurements and scanning electron microscopy (ESEM). As a result, the increase in the weight ratio fusion mass:H2O generates more silica and Aluminum, which allows the formation of well-ordered MCM-41 nanomaterials with high pore volume (0.70 cm(3)/g), high surface area (1044 m(2)/g), and uniform mesoporous diameter (3.67 nm); as a consequence, the increase in the weight ratio fusion mass:H2O leads to an increase in the mass of Al-MCM-41 (9.3 g for 1:8 compared to 5 g for 1:4), whereas the yield of production of mesoporous materials increases to 86%. (C) 2014 Acadamie des sciences. Published by Elsevier Masson SAS. All rights reserved
M Goldberg - One of the best experts on this subject based on the ideXlab platform.
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complex utilisation of ekibastuz brown coal fly ash iron carbon separation and Aluminum Extraction
Journal of Cleaner Production, 2019Co-Authors: Dmitry Valeev, Irina V Kunilova, A Alpatov, A B Mikhailova, M Goldberg, Alex KondratievAbstract:Abstract Fly ash landfills that accumulate a by-product of coal combustion and gasification represent a permanent threat to the surrounding environment due to many factors (air and water pollution, soil contamination, wildlife poisoning, etc). Moreover, disposed coal fly ash may contain significant amounts of valuable elements that are not extracted and potentially wasted. To improve the above situation, a combined ash treatment process was developed for utilisation of the coal fly ash waste from coal-fired power stations. The ash treatment includes three stages: 1) magnetic separation of an iron-containing fraction, 2) carbon separation by floatation, and 3) Extraction of Aluminum by the autoclave hydrochloric acid leaching. The lab-scale results of the ash treatment applied to the Ekibastuz brown coal fly ash from the Omsk power stations (Russia) were presented and discussed. The XRD analysis showed that the fly ash consists primarily of quartz, mullite and magnetite. It was found that the magnetic fraction separated at the first stage is enriched in magnetite (over 20 wt %), the carbon content in the concentrate after flotation increases to 27 wt %, and 90–95% of Aluminum can be extracted during the autoclave acid leaching. The SEM analysis showed that the magnetite phase is grown on the surface of alumosilicate spheres as ∼1 μm cubic crystals. The effect of the autoclave temperature and exposure time on the Al Extraction efficiency was also investigated and analysed in the present paper. The optimal autoclave temperature and exposure time were found to achieve the maximum Al Extraction efficiency. It was also found by the SEM microanalysis that further Extraction of Aluminum is not economically feasible since the remaining Al is evenly surrounded by SiO2 in the fly ash particles.