mineralogy (high processing costs) than lateritic deposits. Most bauxite mines produce Direct Shipping Ore (DSO) bauxite ... The two main sources of silica in bauxite are kaolinite and quartz. Kaolinite • Kaolin - Al 2 Si 2 O 5 (OH) 4 or Al 2 O 3.2SiO 2.2H 2 O
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Processing bauxite high in reactive silica results in high sodium and aluminum in the residue, mainly in the form of sodalite. When treating high-silica bauxite, the provision of replacement sodium hydroxide becomes a major component of the refinery operating cost. With conventional desilication, sodalite particles are fine and associated with ...
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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 …
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The presence of high silica causes high bound-soda losses in the red mud in the Bayer process, but a part of silica content in the bauxite was in the form of chamosite, the bound-soda losses can ...
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TL;DR: A review of existing and potential processes from the open literature that have been proposed for high silica bauxites is presented in this paper, where the processes have been divided into three strategies for reducing soda loss: reducing the input of reactive silica into the process, modifying the process to produce a low soda residue and recovering caustic soda …
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Physicochemical modeling of the process of decomposition of bauxite by hydrochloric acid to determine the main forms of aluminum in solution is based on the experimental data (figure 5).
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A novel process is proposed to extract alumina and silica from high-silica bauxite without residue discharge. 1. Introduction. Silica is a major impurity in bauxite ores, which is commonly present as quartz (SiO 2) and phyllosilicate minerals such as kaolinite (Al 4 [Si 4 O 10](OH) 8), illite (K x Al 4 Si 8−x Al x O 20 (OH) 2) and pyrophyllite (Al 2 [Si 4 O 10](OH) 2). 1,2 When producing ...
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As is seen from Table 1, the µSi of the examined bauxite was 2.04, thus (as stated above) rendering as economically inefficient the use of the Bayer process for the alumina production from the Severoonezhsk bauxite. A relatively high 0.86 wt.% of Cr2O3 poses a significant technological obstacle for the further bauxite treatments by sintering ...
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Many bauxite reserves in India have Al 2 O 3 /SiO 2 ratio of 4 to 6 and hence pose difficulties in production of alumina through the Bayer process. The extraction of alumina from bauxite in low temperature digestion circuit frequently involves a desilication step in which kaolinite dissolves and reprecipitates as sodalite, a caustic insoluble sodium alumino silicate.
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THE PROCESSING OF HIGH QUARTZ BAUXITE Edgar Gasafil, Alessio Scarsellal, Vladimir Hartman., Hans. W. Schmide 1 Outotec , Ludwig-Erhard-Strasse 21,61440 Oberursel, Germany Keywords: "Alumina Retinery, Bayer Process, Bauxite, Quartz, Sand" Abstract Low-grade bauxite refers to bauxite that is high in silica, which is
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More than 99% of the iron could be extracted under optimized conditions [109,110]. Valeev et al. [111] found that pre-calcination of Severoonezhsk bauxite at 700 • C for 0.5 h resulted in a ...
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Silicon is the main impurity in high-silica bauxite [1], [2], [3] and causes scaling on plant surfaces while affecting the quality of alumina during alumina production, using alkaline methods such as the conventional Bayer process [4], [5], [6].With the increasing demand for alumina refineries, the utilization of low-grade high-silica bauxite has attracted substantial …
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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, St. Petersburg, pilot plant with …
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In this paper, a novel process is proposed to extract Al2O3 and SiO2 from high-silica bauxite without residue discharge, that is, sintering bauxite with Na2CO3 followed by two …
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High Iron Diasporic Bauxite Processing Study Xinhua Li, Songqing Gu, Zhonglin Yin Zhengzhou Non-ferrous Metals Research Institute Co. Ltd of CHALCO, Zhengzhou, China ... 13. P. Smith, The processing of high silica bauxites - Review of existing and potential processes, Hydrometallurgy, 98(1-2): 162-176. 14. P.W.Liu, J.Y. Zhu, Q.J. Zhao, J.H ...
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This document will critically review existing and potential processes for the processing of high silica bauxites. High silica bauxites are usually considered to be those with …
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The yield of red mud during the processing of bauxite enriched and calcined at 950 °C was 37.62%. During the autoclave leaching of bauxite without enrichment, the yield of red mud was 71%. ... The Processing of High Silica Bauxites—Review of Existing and Potential Processes. Hydrometallurgy 2009, 98, 162–176. [Google Scholar]
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The mechanochemical processing of bauxite with lime has been investigated. The milling of bauxite and lime mixtures in an attritor mill resulted in the formation of an iron rich hydrogarnet phase ...
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Semantic Scholar extracted view of "The processing of high silica bauxites ― Review of existing and potential processes" by Peter G. Smith. Skip to search form Skip to ... During the production of alumina with the commercial Bayer process, Bauxite Residue (red mud) is produced, which is one of the largest industrial waste streams currently ...
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the process. The silica present in the bauxite tends to be concen-trated in the finer grained fractions, and this charac-teristic makes bauxite amenable to beneficiation by screening techniques. Pearson' has reported that in a bauxite of average composition of 1.58% silica, the minus 100 mesh fraction analysed a silica content as high as 10.30%.
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A desilication process is usually used to treat high-silica bauxite before the Bayer process. However, operational restrictions prevent implementing this approach. The solution must also fulfil the following requirements: - The solution must be at least Technology Readiness Level (TRL) 4 or above.
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The processing of high silica bauxites — Review of existing and potential processes. Hydrometallurgy, (2009),98,p. 162–176. ... Mechanochemical treatment of high silica bauxite with lime. Minerals Engineering, vol. 15, p.211–214, 2000. Article Google Scholar, CRYSMET 2009, código 49772. Download references. Author ...
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The main beneficiation methods of bauxite are washing, flotation, magnetic separation, chemical beneficiation, etc.The process of separating concentrates from bauxite ore is actually a process of removing gangue …
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Bauxite residue is the waste generated during alumina production by Bayer's process. The amount of bauxite residue (40–50 wt%) generated depends on the quality of bauxite ore used for the processing. High alkalinity and high caustic content in bauxite residue causes environmental risk for fertile soil and ground water contamination.
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Aluminum hydroxide finds many industrial applications. Bauxite contains minerals from which aluminum hydroxide $$hbox {Al(OH)}_{3}$$ Al(OH) 3 is leached through Bayer process. Impurities present in it are crucial toward the yield and purity of the end product. Indigenous bauxite ore found at Khushab, Punjab Quarry, was analyzed by X-ray fluorescence …
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Keywords: Bauxite mineralogy, reactive silica, raw materials consumption model, digestion process. 1. Introduction ... Edgar Gasafi, Alessio Scarsella, Vladimir Hartman, etc. The processing of high quartz bauxite, Light Metals 2013, 217-221. 4. Wilmon Wallen-Bryan, Characterization of goethites in poor-setting Jamaican Bayer
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The mechanochemical processing of bauxite with lime has been investigated. The milling of bauxite and lime mixtures in an attritor mill resulted in the formation of an iron rich hydrogarnet phase in bauxite/lime slurries containing greater than 9% CaO. Up to 90% of the quartz contained in the bauxite was found to have been removed by the hydrogarnet reaction.
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Table 1 Classification of methods for processing high-silica bauxite Category Description Limitation Method Development stage Pre-desilication of high-silicabauxitefollowedbythe Bayer process Improving the A/S of high-silica bauxite by physical, chemical and biological bene ciation methods to meet the requirement of the Bayer process
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Li used the roasting-alkali leaching process on high-silica bauxite, with an optimal roasting temperature and time of 1050°C and 30 min, desilication temperature and time of 95°C and 30 min, with the silica leaching rate of 88% for the desilicated minerals. Roasting-alkali leaching desilication is the most widely used method at present, but ...
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In this study, two highly effective Si-solubilizing bacteria (Arthrobacter pascens H19 and Burkholderia anthina G21) were obtained and characterized for their impact on Si and Al …
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