WEBAug 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 18838072829WEBApr 4, 2018 · Due to drawbacks of the direct leaching route from bauxite residue, such as silica gel formation and low selectivity towards these valuable metals, a novel leaching process based on oxidative ...
WhatsApp: +86 18838072829WEBMar 1, 2019 · During acid leaching of bauxite residue (red mud), the increase in dissolution of rareearth elements (REEs) is associated with a substantial codissolution of iron; this poses problems in the downstream processing ( solvent extraction or ion exchange). Six different slags generated by reductive smelting of the same bauxite .
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 18838072829WEBApr 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 ...
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 18838072829WEBMay 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 .
WhatsApp: +86 18838072829WEBJun 4, 2019 · For the first time this study showed a process combination of acid leaching and adsorption on zeolite for the recovery of Ga from bauxite residue, therefore process parameters were developed for the study in batch .
WhatsApp: +86 18838072829WEBDec 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 ...
WhatsApp: +86 18838072829WEBIn 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.
WhatsApp: +86 18838072829WEBOct 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 ...
WhatsApp: +86 18838072829WEBApr 4, 2017 · A full process was designed to recover scandium from bauxite residue. • Scandium is leached by sulfationroastingleaching and multistage leaching. • [Hbet][Tf 2 N] was used for the extraction of scandium from the leachate. • Separation between Fe and Sc was improved by reduction of Fe(III) to Fe(II).
WhatsApp: +86 18838072829WEBDec 8, 2009 · A kind of composite brick made from the Bayer process bauxite residue was produced depending on the combined solidifying performance of cement and limefly ash ... The first leaching process was completed using 6 mol/L HCl solution with the leaching rate of Sc 2 O 3 being over 80% and the leaching rate of TiO 2 at approximately 1%.
WhatsApp: +86 18838072829WEBNov 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 .
WhatsApp: +86 18838072829WEBOct 21, 2016 · Acid leaching. In order to recover scandium and other rare earth metals, red mud is often dissolved by leaching with acids. The investigations on acid leaching of scandium from bauxite residue were extensively carried out [51, 53, 78, 89–93].Zhang et al. [] used HCl for leaching of scandium from red mud, and the optimum leaching .
WhatsApp: +86 18838072829WEBOct 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 ...
WhatsApp: +86 18838072829WEBMar 21, 2023 · The bauxite residue leaching process to extract REEs can also be performed using alkaline reagents . Yatsenko and Pyagai conducted a leaching experiment of bauxite residue in an alkaline solution using NaHCO 3 as a leaching reagent to extract scandium. Scandium leaching occurs by forming complex anionic compounds with .
WhatsApp: +86 18838072829WEBSep 1, 2022 · Based on the above results of twostage leaching process, the optimal roasting temperature and duration for the SiO 2 and Al 2 O 3 extraction from highsilicon bauxite are 1050 °C and 30 min, and the corresponding extraction efficiencies of SiO 2 and Al 2 O 3 are % and %, respectively.
WhatsApp: +86 18838072829WEBMar 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.
WhatsApp: +86 18838072829WEBJun 1, 2024 · Bauxite residue (BR) is a byproduct of bauxite refining using Bayer process for alumina production, which contains numerous valuable components: iron (Fe), aluminum (Al), and rare earth elements such as scandium (Sc). The main issue of previous research for the Sc extraction from BR was the low extraction efficiency or high Fe coextraction.
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 .
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