Process flowsheet of bauxite ore to remove silica and reactive silica from the ore. 4.7.1.2. Magnetic separation of the bauxite ore. Magnetic separation had shown promises for some of the bauxite ores (Bhagat et al., 2001, Bhagat et al., 2006).
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1. Introduction. Bauxite resources are widely distributed in the world and are the main resources for aluminum production (Ma et al., 2009, Ma et al., 2011).Almost all of bauxite ores in China are diasporic-characterized and do not meet the demands in the Bayer process for aluminum production due to their high silica content and low Al 2 O …
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Leaching Kinetics Both bauxite and activated bauxite begin to dissolve upon contact with the alkaline solution (4 M and 8 M NaOH), the main elemental (Si, Al, Ti and Fe) concentrations in the liquor are shown in Fig. 1.The solution silicate dissolution -precipitation pattern is seen Fig. 1a, which is similar to that of pure kaolinite or metakaolin.
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According to the 2021 alumina and bauxite-related data released by the U.S. Geological Survey [29], the known bauxite resources worldwide were estimated at 32 billion tons, distributed in more than 50 countries.The largest bauxite reserves in the world were in Guinea (23%) and Australia (17%).
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Strains H19 and G21 could significantly remove Si from the high silica bauxite by the production of organic acids and expolyssaccharides. Furthermore, our findings indicated that Burkholderia anthina G21 had a greater bio-desilication from the bauxite than Arthrobacter pascens H19 by producing more H + and higher organic acids …
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recovery of alumina and 45.9 % recovery of silica to product. Keywords: Bauxite beneficiation, Clay removal, Silica reduction, Hydrocyclones. 1. Introduction Bauxite is the main ore for production of metallic aluminum. Production is generally carried out by the Bayer process to form alumina, followed by the Hall-Héroult process to carry out the
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The dissolution of silica from bauxite residue during acidic leaching is a very complex process controlled by a chemical reaction stage, i.e. silica gel formation as consequence of hydrolysis of silica, and a diffusion stage caused by the partial adsorption of this silica gel layer on the surface of the particles.
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IMPROVED METHODS FOR REMOVAL OF SILICATE DEPOSITS T.R. McCartney1, Samar Gharaibeh1, Roxanne Shank1 1 # 2-321 37 N.E. Calgary, AB, T2E6P6 mccartney.thomas@cleanharbors: None ABSTRACT The removal of silica scale deposits from process equipment represents a substantial challenge in chemical cleaning.
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A schematic of the silica removal from bauxite and the desilication process is presented in Fig. 1.All experiments were carried out at 95 °C.The desilication test was carried out in a constant temperature (≈95 °C) oil bath with electromagnetic stirring (≈300 rpm), and RM and/or CaO were added.After filtration and cooling, the desilication …
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Batch pre-desilication test results of a high reactive silica boehmitic bauxite from Nyírád (Hungary) ar e shown on Figures 4.4-9 [8]. The bauxite contained 48.8 % Al 2 O 3, of which 37 % was ...
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The more is the silica, higher is the soda consumption which increases the cost of alumina production. Physical beneficiation techniques are employed to reduce the reactive silica content of bauxite. Based on several investigations it has been made possible to remove ~30% of silica with 92% recovery depending on the characteristics of the ore.
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Simulation studies have shown that calcium and aluminum combine with silicon to form hydrated calcium silicate, silica–alumina gel, and zeolite, respectively, thereby hindering …
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Cationic reverse flotation of kaolinite from bauxite is an alternative to adequate high silica bauxites to the specifications of the Bayer process. However, the presence of clay minerals influences the slurries rheology decreasing the …
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Five routes for bauxite silica reduction were analyzed considering the inclusion of tertiary stages of desliming in cyclones. Process simulations pointed to a potential solution for the reduction of reactive silica in Paragominas' bauxite, setting tertiary cyclone in fine classification circuit (26″ cyclones) as the most attractive solution ...
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Beside the processing behaviour of the main constituents of bauxite such as hydrated alumina and silica minerals, the Chapter covers the impact of other constituents, such as titania, iron ...
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For this reason, they are also referred to as gibbsitic alumina and kaolinitic silica. High-grade bauxites contain N41 wt% AvAl 2 O 3 and b5 wt% RxSiO 2, while low-grade bauxites contain b 41 wt ...
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silica removal efficiency. Additionally, ultrasonic irradiation treatment has been employed to eliminate silica from the liquor spent, as demonstrated by McCormik et al. [2]. ... "Silicate" bacteria for silicate removal from bauxite and the enhancement of Al 2 O 3 in low-grade bauxite, although commercial-level testing is pending. It is ...
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In this study, low-grade bauxite ore from Seydişehir (Konya, Turkey) containing 57.33% Al2O3 and 9.01% SiO2, (A/S = 6.36) was investigated to determine the modal mineralogy and mineral liberation ...
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Fig. 1 Flowsheet of iron removal process from Severoonezhsk bauxite The efficiency of iron leaching (α) was calculated by α=[VCFe/(mwFe)]× (1) where CFe is the iron concentration in the filtrate detected by inductively coupled plasma optical emission spectrometry (ICP-OES), g/L; V is the volume of the iron chloride solution, L; m ...
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In the process, due to the small particle size, kaolinite is usually removed by attrition and washing of coarse material followed by desliming using hydrocyclones. In the Bayer …
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A process for removing silica from bauxite is disclosed. The method includes the step of mixing bauxite with a caustic liquor to form a mixture and to dissolve and stabilise at least a substantial part of the reactive silica from the bauxite. The caustic liquor is selected to have a high caustic concentration and a high alumina content.
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Learn about the chemistry, kinetics and reactor design of the Bayer process, a chemical method to refine aluminium hydroxide from bauxite. The chapter covers the effects of …
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Aluminum industries use bauxite as the major raw material . Bauxite containing less than 50% Al 2 O 3 is called low-grade bauxite ore, which is generally used for the production of aluminum appliances such as abrasives, ceramics, and refractories . The presence of impurities, including silica, iron oxides, and calcium contribute to the …
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Acid selection for REEs leaching from bauxite residue. To choose the best leaching agent and optimum operating conditions, a systematic investigation was performed using HNO 3, HCl, and H 2 SO 4 ...
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DOI: 10.1016/J.MINENG.2008.09.001 Corpus ID: 97467177; Separation of silica from bauxite via froth flotation @article{Massola2009SeparationOS, title={Separation of silica from bauxite via froth flotation}, author={Camila Peres Massola and Arthur Pinto Chaves and J.R.F. de Lima and Christian Fonseca de Andrade}, journal={Minerals Engineering}, …
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2.Materials and Methods Samples from two fractions of the geological profile from Brazilian bauxite were properly suited to carry out the tests on bench scale, using methods previously described [7].
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Deposits of bauxite ores near aluminum smelters often possess an excessively high percentage of silica. Development of such high-silica ores would be beneficial to alumina producers. Therefore, unique industrial and operational experience in the field of high-silica bauxite processing was gained at the Russian National Aluminium-Magnesium Institute, …
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Alumina content and silica content as results of flotation were analyzed by XRF. The results of XRF of flotation products show that increasing of alumina content and decreasing of silica content. The optimum pH range of bauxite flotation using DDA and AERO 3000C as collectors can be achieved at pH 4 – 10.
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Bauxite underwent cyclic desilication and the alumina/silica ratio was increased from ∼4.1 to >7.5. Effective utilization of red mud and alkali-silicate solution …
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Role of indigenous microbes in the formation and conversion of bauxite minerals is illustrated. Many types of microorganisms such as fungi, heterotrophic and autotrophic bacteria and yeasts inhabit bauxite ore deposits bringing about biogenesis and biomineraliztion. Organisms capable of iron oxidation and reduction and solubilising …
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Iron Removal from Bauxite by Oxalic Acid and Further Al Extraction by High‑Pressure Alkali Leaching Aslıhan Cam1 · M. Deniz Turan1 Received: 7 July 2022 / Accepted: 28 March 2023 / Published online: 17 April 2023 ... for the silica modulus (M Si) of bauxite to be higher than 7, and this is highly important for the economy of the process ...
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For achieving this purpose, iron removal tests were performed on bauxite samples with an alumina to silica modulus of 0.73. After determining the appropriate iron removal method among the magnetic ...
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Bauxite residue (BR) is generated as a by-product of the Bayer process. Approximately 1.2 tons of BR is generated per ton of alumina production but the quantity of bauxite residue depends upon on the quality of the processed bauxite ore and the processing parameter (Primary Aluminium Production).The annual generation of BR in …
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Abstract When producing alumina from aluminum-containing raw materials (bauxite, alunite), it is important to control the silica level in a solution of sodium aluminate. The studies show that this adsorbent having layered binary hydroxides, such as hydrocalumite sulfate AFm-SO4, is characterized by excellent desilication properties. …
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In this paper, a novel process is proposed to extract Al 2 O 3 and SiO 2 from high-silica bauxite without residue discharge, that is, sintering bauxite with Na 2 CO 3 followed by …
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Bauxite reaction residue (BRR) produced from the poly-aluminum chloride (PAC) coagulant industry is a solid acidic waste that is harmful to environment. A low temperature synthesis route to convert the waste into water glass was reported. Silica dissolution process was systematically studied, including the thermodynamic analysis and the influence of …
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Silica gel formation is one of the most common problems in hydrometallurgical processing of silica containing resources such as BR with 7 wt. % Si content which deteriorates sample handling and ...
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In this study, extraction of aluminum-, iron-, and titanium-bearing constituents from diaspore-type bauxite ores was investigated by stepwise treatment consisting of pre-desilication via alkali-leaching of bauxite ore, extraction of alumina via Bayer process, and recovery of iron from red mud via magnetic separation. The pre …
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