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 .
WhatsApp: +86 18838072829WEBJan 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 .
WhatsApp: +86 18838072829WEBOct 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), .
WhatsApp: +86 18838072829WEBMay 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 .
WhatsApp: +86 18838072829WEBThe 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. ...
WhatsApp: +86 18838072829WEBThe Bayer process is the most commonly used refinement route, though certain countries use alternatives called the combined or parallel BayerSinter process and the Nephelinebased process [20, 37].This section describes purely the Bayer Process. Due to the impurities in the bauxite ore, it requires treatment to produce purer alumina, Al 2 O 3 .
WhatsApp: +86 18838072829WEBAug 4, 2020 · leaching process and a formula different than Equation (5) would be obtained (Levenspiel 1999). Figure 2: Leaching in a highly porous particle. of constant size. 4 F. Faraji et al.: Kinetics of ...
WhatsApp: +86 18838072829WEBNov 4, 2022 · The raw material for the Bayer process is most commonly mined bauxite, a rock containing aluminium, which – as we already know – also contains many other substances (admixtures) in addition to aluminium oxide hydrates‑, such as iron‑, titanium and silicon oxides in particular.
WhatsApp: +86 18838072829WEBJul 1, 2019 · During the Bayer process for alumina production, the molecular formula of the bauxite residue is approximately equivalent to Na 2 O·Al 2 O 3 · 2 ·nH 2 O. This means that 1 kg of SiO 2 in bauxite will produce 1 kg of Al 2 O 3 and kg of Na 2 O in bauxite residue. Thus, the extraction efficiency of alumina is low when processing low .
WhatsApp: +86 18838072829WEBJan 7, 2022 · 1. Introduction. Red mud (RM) is a solid waste generated by alkali (NaOH) leaching of bauxite by the Bayer process for alumina production [].More than one ton of RM is produced for one ton of alumina (Al 2 O 3), and over 150 Mt of RM is annually stored in landfills and sea [].The RM utilization degree is extremely low due to the high Na, Al, .
WhatsApp: +86 18838072829WEBDec 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 .
WhatsApp: +86 18838072829WEBJun 1, 2018 · Bauxite residue is a highly alkaline waste containing soluble alkaline anions, which can cause environmental concerns. The optimal leaching conditions, distribution of alkaline anions, types of pivotal alkaline anions and their dissolution behaviors were investigated based on the combination of single factorsorthogonal experiments and .
WhatsApp: +86 18838072829WEBJun 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 .
WhatsApp: +86 18838072829WEBJun 1, 2020 · During water leaching, the watersoluble ions in bauxite residue were leached out. The CO 3 2−, HCO 3 −, Al(OH) 4 − and OH − were selected as the typical anions to evaluate leaching behavior of alkaline solid phases in bauxite residue. With the increase of L/S ratio, the leaching concentrations of CO 3 2−, HCO 3 − and Al(OH) 4 − .
WhatsApp: +86 18838072829WEBJun 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.
WhatsApp: +86 18838072829WEBJan 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 ...
WhatsApp: +86 18838072829WEBFeb 16, 2019 · The Bayer process is the main process applied to obtain alumina from bauxite ore. The mineral is dissolved using sodium hydroxide in digesters, which obtain sodium aluminate in solution and a solid phase called red mud; the two are separated by the clarifiion process [1, 2].Brazil is the third country in bauxite reserves in the world, .
WhatsApp: +86 18838072829WEBJun 1, 2016 · Leaching efficiency depends on the bauxite residue composition and process parameters, such as reagent type and concentration, retention time, temperature, and solid/liquid ratio [2,3,5,6,9,10]. ...
WhatsApp: +86 18838072829WEBOct 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 ...
WhatsApp: +86 18838072829WEBThe 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 ...
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