WEBThe results indied that leaching of bauxite is the rate controlling process. The activation energy was determined to be kJ/mole, which was characteristic for a chemically controlled process. In this paper the results of a leaching kinetics study of bauxite ore with sodium hydroxide are presented. The effect of ore particle size, sodium ...
WEBThe results have been obtained as following: (i) Temperature play an important role in iron leaching from bauxite residue. Higher temperature is favor of Fe (III) leaching from bauxite residue. (ii) The leaching process is applicable to the intraparticle diffusion model and the apparent activation energy of model of leaching is found to be 17. ...
WEBJan 1, 2022 · The process combines carbothermic smelting, acid baking – water leaching, and thermal desulfation to efficiently extract the target materials from the bauxite residue without producing hazardous solid residues, while enabling the recovery and recycling of the major process reagents: CaO, SiO 2, and H 2 SO 4. Through .
WEBJan 24, 2024 · The following are the examples of leaching process. Leaching of Bauxite. An example of a leaching process is the leaching of bauxite or Al 2 O 2 O with concentrated and heated sodium hydroxide. The concentrated NaOH here prefers to dissolve the aluminium contained in the provided bauxite, ...
WEBNov 27, 2023 · Bauxite residue (BR), an alkaline industrial waste, is a major byproduct of the alumina production process known as the Bayer process. The Bayer process generates a byproduct known as bauxite residue (red mud). This residue was leached with sulfuric acid in a pilot plant of Mytilineos to recover scandium. Scandium was .
WEBJan 7, 2022 · Bauxite residue, known as "red mud," is a potential raw material for extracting rareearth elements (REEs). The main REEs (Sc, Y, La, Ce, Nd, Nb, and Sm) from the raw bauxite are concentrated in RM after the Bayer leaching process. The earlier worldwide studies were focused on the scandium (Sc) extraction from RM by concentrated acids to .
WEBSoda Sintering/Leaching Process Dried homogenized bauxite residue was sintered in muffle furnace with 50% excess of sodium carbonate (Na2 CO3, Sigma Aldrich, > % Purity) from stoichiometric amount required for sodium aluminate conversion, which amounted to 25 g Na2 CO3 for 100 g of bauxite residue. Sintering was performed in .
WEBMar 1, 2020 · Depressions were filled by in situ detrital material and the weathering products derived from erosional areas, generating the initial materials involved in the subsequent leaching. The quality of the bauxite generated during this process was controlled mainly by the prevailing leaching conditions.
WEBJun 28, 2023 · The Bayer process is the main method of alumina production worldwide. The use of lowquality bauxites for alumina production results in the formation of a significant amount of technogenic waste—bauxite residue (BR). The Bayer reductive method is one possible way to eliminate BR stockpiling, but it requires highpressure .
WEBAug 11, 2016 · Therefore, the leaching process with dilute HNO 3 has been performed and optimized at a pilot scale for the recovery of scandium from bauxite residue . According to Petrakova et al., leaching with nitric acid could be a problem due to the absorption of nitrate ions on the residue, so that large volumes of water are needed for their removal [ .
WEBOct 10, 2002 · Published chemical analysis and leaching studies of bauxite residue focus on the concentration of Sc, because Sc represents 95% of REE's financial values found in BR (case of Greek Bauxite ...
WEBJan 1, 2023 · The leaching of highsilica bauxite using a mixture of NH 4 HSO 4 and H 2 SO 4 was analyzed using empirical SCM equations ((7), (8), (9)) to determine the optimal process by estimating the coefficient of determination (R 2). The following kinetic equation is applicable if the leaching process is limited by the surface reaction: (7) 1 – 1 ...
WEB1. Introduction. Depending on the composition and properties of the feedstock, alumina (Al 2 O 3) is produced by a variety of industrial processes [].Lowsilica bauxites are used worldwide for the production of alumina by the most energyeffective Bayer process, which is based on alkaline leaching with continuous regeneration of the solution by the .
WEBJul 1, 2010 · The Al2O3 recovery, as well as the kinetic parameters, during the Bayer leaching process of different bauxite types strongly depends on their mineralogical composition. In this paper an attempt was made to develop a mathematical model which enables calculation of the Al2O3 recovery from boehmitediaspore or gibbsiteboehmite .
WEBJul 15, 2019 · The current study put the emphasis on developing a novel and environmentally friendly waste valorization process, called "acidbaking waterleaching", to recover scandium from bauxite residue produced by the aluminum industry.
WEBNov 18, 2016 · Bauxite residue (red mud) with a high alumina content requires large amounts of fluxes during smelting, which increases the overall process cost, the energy consumption during smelting, and the acid consumption during slag leaching and decreases the throughput of bauxite residue in the smelting phase. Therefore, alumina .
WEBOct 1, 2016 · Semantic Scholar extracted view of "Study on the roasting and leaching behavior of highsulfur bauxite using ammonium bisulfate" by Z. Lou et al. Skip to search form Skip to ... In this study, we propose a novel temperatureprogrammed ammonium chloride (NH4Cl) roasting–waterleaching process to extract nickel (Ni), cobalt (Co), .
WEBOct 15, 2023 · The REE patterns of Alrich layers were also associated with weathering and leaching process, the loss of most LREEs within bauxite ores (Fig. 9 A) and the strong negative correlation between (La/Yb)N ratios Al 2 O 3 contents (Fig. 8 H) indied REEs were also affected accompanying the accumulation of Al during the chemical weathing .
WEBFeb 16, 2019 · The process of leaching using fungalproduced organic acids as a leaching solution results in removal of 80% of total iron from bauxite . Papassiopi et al. [ 64 ] investigated the combined effect of ethylenediamine tetracetic acid (EDTA) and metabolism of Desulfuromonas palmitatis in removing iron oxides from the bauxite .
WEBMay 15, 2015 · The leaching process with dilute HNO 3 was performed at pilot scale and optimized for the extraction of scandium from bauxite residue (OchsenkühnPetropoulou et al., 2002). Xue et al. (2010) found that at a reaction temperature of 90 °C and an L/S ratio of 3:1, over 80% of the scandium in bauxite residue could be leached by H 2 SO 4 .
WEBIn the leaching method, bauxite ore is digested with a concentrated solution of NaOH that produces 'X'. When C O 2 gas is passed through the aqueous solution of 'X', a hydrated compound 'Y' is precipitated.
WEBNov 1, 2023 · For complete valorization of bauxite residue, iron content needs to be lowered by recovering it through smelting reduction followed by slag leaching for the recovery of other metals (, Ti and REEs). Smelting reduction process becomes uneconomical with high alumina as it hinders efficient separation of metal and slag .
WEBJan 1, 2023 · The extracted Al in these studies exceeded 80%. However, the kinetics of the leaching process and the behavior of the major and trace elements have not been examined. Therefore, the leaching of highsilica bauxite from the Severoonezhsk deposit (μ Si < 3) using a mixture of NH 4 HSO 4 and H 2 SO 4 was investigated for the first .
WEBDec 1, 2010 · This article presents the results of experimental investigations of the leaching process kinetics for different types of bauxite: gibbsite, boehmite, diaspore, and gibbsite/boehmite and ...
WEBOct 1, 2007 · The behavior of Al and Si in red mud in the leaching process of diaspore bauxite with NaOH submolten salt was investigated. The effects of reaction temperature, mass ratio of alkali to ore and ...
WEBApr 1, 2021 · The leaching of boehmitekaolinite bauxite from the Severoonezhsk deposit mine (Arkhangelsk region, Russia) using a mixture of NH 4 HSO 4 and H 2 SO 4 was investigated for the first time. The bisulfate method, which combines the advantages of the acidic and alkaline methods, involves bauxite leaching, precipitation of ammonium alum ...
WEBDec 15, 2023 · 1. Introduction. Bauxite residue is an industrial solid waste with high alkalinity produced in the alumina refining process, which contains a variety of elements such as iron, aluminum, sodium, titanium, silicon, calcium, and magnesium (Fu et al., 2022; Shao et al., 2021).With the rapid development of the alumina industry, China has been .
WEBMay 10, 2019 · Water leaching process is also recommended as a promising strategy to ameliorate the high salinity and alkalinity of bauxiteprocessing residue (Zhang et al., 2011) and high sodium (Na +) concentration has been reported in bauxiteprocessing residue leachate (Xiangfeng Kong et al., 2018a). Taking full advantage of the available water .
WEBJul 28, 2019 · The novel Sandy DSP SinterLeach process provides a lower energy intensity method for the recovery of sodium and aluminium lost to bauxite residue. The present study is an investigation into the ...
WEBJun 1, 2019 · The ideal conditions for the leaching process was determined through response surface methodology (RSM) to be H3PO4 concentration of mol/L, L/S ratio of 11 mL/g and leaching temperature of 40 ...
WEBJun 1, 2020 · Bauxite residue, a byproduct of alumina manufacture, is a serious environmental pollutant due to its high leaching contents of metals and caustic compounds.
WEBOct 15, 2023 · Bauxite resources in China are considerably large (Ling et al., 2015, Sun et al., 2018), while they are discovered mainly within Carboniferous and Permian strata of South China and North China cratons (Yu et al., 2019). ... Geochemistry characteristics and leaching process of the typical weathering profile within a karsitc depression revealed ...
WEBFeb 3, 2024 · This study presents a process for the simultaneous recoveryRecovery of metals from bauxite residueBauxite residue (BR) at relatively lower temperatures using H2 reduction to achieve zerowaste discharge (minimal waste generation) of BR. The proposed methodMethod...
WEBDec 1, 2017 · The commercial Ga is the byproduct from Bayer liquor obtained from the bauxite leaching process and zinc residue generated by hydrometallurgical treatment of zinc concentrates (Zhao et al., 2012, Frenzel et al., 2016, Geological Survey, 2017). In the Bayer process, approximately 70% of the Ga is leached from the bauxite into the .
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