A novel process consisting of a roasting pretreatment followed by two-stage leaching for alumina and silica extraction was proposed to achieve the comprehensive …
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World reserves of bauxite include vast quantities of ore which at present are sub-economic due to high levels of reactive silica that cause expensive loss of caustic soda during Bayer processing. As the economic reserves of high grade ores diminish, …
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Low-grade bauxite refers to bauxite that is high in silica, which is present as kaolin, or quartz, and therefore requires different approaches for processing. With digestion of …
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Alkali leaching of silica from activation-roasted high-silica bauxite can increase the mass ratio of alumina to silica (A/S) in the residue and favors alumina extraction by the Bayer process.
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Bauxite residue obtained from the Bayer's process has a high content of NaOH making its disposal difficult. This Bauxite residue is used as a pozzolanic material due to its high silica and alumina contents [44]. Direct disposal of Bauxite residue obtained from the Bayer's process into the environment leads to soil, air, and water pollution ...
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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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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 …
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The bauxite in the eastern region of China is diasporic type with high silica containing about 8-16% SiO 2. The main silica minerals in the bauxite are kaolinite, chamosite and i1lite.
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This paper is one of a study that implements reverse flotation methods as an alternative beneficiation on bauxite processing. This study is aimed at decrease silica content and increase alumina content in bauxite so its qualified as feed of Bayer Process.
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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 …
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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 …
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The production of aluminum from bauxite is a two-step process: refining bauxite to obtain alumina and smelting alumina to produce aluminum. Bauxite contains a number of impurities, including iron oxide, silica, and titania. If these impurities are not removed during refining, they will alloy with and contaminate the metal during the smelting ...
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The main silica minerals in the bauxite are kaolinite and chamosite. 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 be greatly reduced with chamosite mineral by using Bayer process.
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The process stages are: 1. Milling. The bauxite is washed and crushed, reducing the particle size and increasing the available surface area for the digestion stage. ... Bauxites that have high levels of silica (SiO 2) go through a process to remove this impurity. Silica can cause problems with scale formation and quality of the final product. 3 ...
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12.2 ALUMINA FROM BAUXITE: THE BAYER PROCESS. Bauxite, the principal ore used for aluminum smelting, is named after Les Baux, Provence, the village where the first deposits were discovered. ... which is especially useful with high silica or high iron oxide bauxites (Eq. 12.6).
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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 …
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The Processing of High Silica Bauxites—Review of Existing and Potential Processes. Hydrometallurgy, 2009. 98(1): p. 162–176. Google Scholar Rezaee Rad, M., et al., Investigation of parameters affecting desilication of diasporic bauxite in Jajarm mine by thermo-chemical treatment. Journal of Mining and Environment, 2017.
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Bauxite is formed through a weathering process that occurs in tropical and subtropical regions with high rainfall. The process involves the breakdown and alteration of aluminum-rich rocks, ... In the case of bauxite formation, silica and other minerals are leached out of the rock, leaving behind aluminum-rich minerals.
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Low-grade bauxite refers to bauxite that is high in silica, which is present as kaolin, or quartz, and therefore requires different approaches for processing. With digestion of gibbsitic bauxites ... refineries which process high quartz bauxite also …
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The presence of high silica causes high bound-soda losses in the red mud in the Bayer process, so most of the high silica digestion were carried out on the sampIes by Soda-lime sintering, but apart of silica content in the bauxite was in the 47 Temperature of Retention Predesil ication Reaction (0C) Time (hr.) Efficiency (%) 98 2 53.3
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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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Australian bauxite mines are known for their high quality ore which is determined not just by the aluminium content but also by associate minerals, such as iron oxides, anatase and, in particular, the amount of reactive silica (RxSiO 2). The large bauxite resources at Weipa and Amrun (>3000 Mt) in Queensland and Gove (>190 Mt) …
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Bacteria play an important role in bio-desilication of high silica bauxites. However, low bio-desilication efficiency and unknown mechanisms limit the use of bacteria in bio-desilication of bauxite.
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Techniques and mineral chemistry of high silica bauxite for the Bayer process @inproceedings{Wang2008TechniquesAM, title={Techniques and mineral chemistry of high silica bauxite for the Bayer process}, author={Hai-peng Wang and Peter G. Smith and Don C. Ibana and Bingan Xu and Jian Zhang and Yao Zhang and Bianca …
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A process of dissolution Severoonezhsk deposit boehmite-kaolinite bauxite by hydrochloric acid, as well as the processes that occur during open-air calcination, were investigated.
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1. Introduction. 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 …
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Thermal activation of bauxite has been proposed to enable removal of organic carbon and reducing boehmite digestion temperature. However, there is limited published research about how thermally activated bauxite behaves at pre-desilication (<100 °C) conditions. Combining x-ray diffraction and scanning electron microscopy energy dispersive …
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The processing of high silica bauxites — Review of existing and potential processes. Hydrometallurgy, (2009),98,p. 162–176. Article Google Scholar
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Request PDF | The Processing of High Silica Bauxites — Review of Existing and Potential Processes | World reserves of bauxite include vast quantities of …
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A new approach was applied to processing high iron diasporic bauxite which involves firstly pre-processing at low temperature with high αK liquor and then digesting at high temperature with recycled mother liquor.
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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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Many bauxite reserves in India have Al2O3/SiO2 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...
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High silica bauxite Thermal activation X-ray diffraction Zeolite LTN Sodalite Zeolite LTA Introduction The increasing reactive silica content (mainly kaolinite) of bauxite has a major cost implication and is often a defining parameter as to whether the mineral can be economically processed. In the Bayer digestion process, kaolinite dissolves
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The sandy DSP process concept is introduced to address the challenge of processing high-silica bauxite. In the sandy DSP process, the DSP is coarsened by reaction seeding and supersaturation control during an …
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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 …
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