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 ...
WhatsApp: +86 18203695377WEBNov 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 18203695377WEBJul 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 .
WhatsApp: +86 18203695377WEBAccording to the literature, the leaching process depends on the type of bauxite residue, because mineralogical composition and morphological distribution of bauxite residue determine the best leaching agent. Hence, the REE recovery process from bauxite residue must be tailored for a given source 5. Most of the previous studies were focused .
WhatsApp: +86 18203695377WEBAug 1, 2014 · The optimum conditions for the process parameters were obtained as: 675 0 C calcination temperature; 97 0 C leaching temperature; mol/l acid concentration; g/ml solidtoliquid ratio ...
WhatsApp: +86 18203695377WEBJul 15, 2019 · In this study, an alternative twostage extraction process to acid roastingwater leaching was investigated to recover scandium from a Canadian bauxite residue. The process is called acid bakingwater leaching, in which bauxite residue is mixed with 98 wt% H 2 SO 4, baked in a furnace at 200–400 °C, and leached in water at ambient .
WhatsApp: +86 18203695377WEBBauxite is the principal ore of aluminium. The impurities present in bauxite are SiO2, iron oxides and titanium oxide (T iO2). Concentration is carried out by heating the powdered ore with a concentrated solution of NaOH at 473 – 523 K and 35 – 36 bar pressure. This process is called digestion. Al2O3 is extracted out as sodium aluminate.
WhatsApp: +86 18203695377WEBMay 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 18203695377WEBMar 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 18203695377WEBFeb 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 18203695377WEBApr 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 18203695377WEBJan 1, 2016 · PDF | On August 3, 1888 German Patent No. 43977 entitled "A Process for the Production of Aluminum Hydroxide" was issued**. ... The Bayer Process involved the pressure leaching of bauxite with ...
WhatsApp: +86 18203695377WEBJun 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 18203695377WEBJun 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 18203695377WEBSep 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 18203695377WEBNov 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 18203695377WEBJun 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 18203695377WEBJun 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 18203695377WEBFeb 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...
WhatsApp: +86 18203695377WEBOct 1, 2016 · The orthogonal experiment of highsulfur bauxite leaching process. Table 4 lists the schedule of the orthogonal test in which the three factors liquid–solid ratio (A), leaching temperature (B) and leaching time (C) are selected. Each factor has three levels to be optimized.
WhatsApp: +86 18203695377WEBOct 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 18203695377WEBNov 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 .
WhatsApp: +86 18203695377WEBThe 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 ...
WhatsApp: +86 18203695377WEBOct 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 ...
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