High silica bauxites
bauxite grades and the importance of research into economic ways of processing of high silica bauxites. The major cost penalty associated with processing high silica bauxites is
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Beneficiation of bauxite ores
The other challenge faced by the industry is the management of large volumes of bauxite residue generated from processing bauxite ores. Hindalco has become the world's first company to achieve red mud utilization in cement plants across three of its bauxite refineries. ... Beneficiation of high silica bauxite ores of India an innovative ...
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A Novel Sustainable and Facile Method in Alumina Industry: Pre
Thus, because the silica removal process has not been clearly elucidated, the advanced low-grade bauxite utilization techniques cannot be applied on a large scale. However, the reasonable recycling of ASS for high-silica bauxite is a significant issue that must be addressed for industrial production [18,19,20,21].
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Economic Processing of High Silica Bauxites
High silica bauxites are usually considered to be those with reactive silica contents1 in excess of ~8% by weight of the bauxite. "Economic processing" is meant to imply production of...
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Treatment and Beneficiation of High Silica Bauxite
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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Bauxite | Properties, Formation, Uses » geologyscience
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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Selective Processing of the Kaolinite Fraction of High …
Selective processing for the FKF of high-silicon bauxite was carried out via various methods, including preliminary thermal transformation, chemical enrichment, autoclave leaching in a circulating aluminate solution, …
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Bauxite Beneficiation: An Approach to Value Addition in Mining
adopted for high silica ores, whereas naturally occurring low silica bauxite of Guinea are used as DSO. While there is no washing in these mines, some processing such as
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Extraction of alumina and silica from high-silica bauxite by …
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 two-step …
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THE PRACTICE OF BAUXITE ORES PROCESSING
The bauxite to be sent to the refinery must fit significant restrictions: • alumina grade - there must be a minimum grade for economical processing; • reactive silica grade-the sílica contained in clay minerais reacts with sodium hidroxide during refining, increasing
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Extraction of alumina and silica from high-silica bauxite by …
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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Mechanochemical treatment of high silica bauxite with lime
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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Extraction of alumina and silica from high-silica bauxite by …
Bauxite residue is a solid waste left over after extracting alumina from bauxite. When high-silica bauxite is used as a feedstock for alumina production, more bauxite residue is discharged compared to processing high-grade bauxite. 30 At present, most bauxite residues are sent to dams for storage, taking up large amounts of land and incurring significant costs for the …
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The processing of high silica bauxites
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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EP0950020A1
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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Four Bauxite Beneficiation Methods
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 minerals and harmful impurities, and separating high-aluminum minerals and low-aluminum minerals to obtain concentrates with a high aluminum …
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The Bayer digestion behaviour of transition aluminas formed from
Consequently, bauxite containing a reactive silica (total silica content of all minerals that react under given processing conditions) content greater than ~ 8% cannot be economically processed using the Bayer process (Smith, 2009). These problems are exacerbated as high quality (low reactive silica) bauxite supply diminishes and more stringent ...
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THE PRACTICE OF BAUXITE ORES PROCESSING
The bauxite to be sent to the refinery must fit significant restrictions: • alumina grade - there must be a minimum grade for economical processing; • reactive silica grade-the sílica contained in …
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Beneficiation of Bauxite Ore Characterized by Low-Grade …
cost-effective processing methods for low-grade bauxite. This paper elucidates several beneficiation techniques, including crushing, size classification, washing, scrubbing, and …
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Extraction of alumina and silica from high-silica bauxite by …
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 two-step leaching with water and sulfuric acid. The effects of the sintering parameters on the process were investigated, and the phase transformations during ...
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Improving bio-desilication of a high silica bauxite by two highly
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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The Bayer digestion behaviour of transition aluminas formed from
To maintain economic alumina production, a number of investigations have been conducted to try and minimise the impact of silica on the economics of existing processes and to develop new methods for processing high silica bauxite (Smith, 2009).One of the methods is to effectively pre-concentrate high silica bauxite or aluminous minerals by the roast-leach …
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Mechanochemical treatment of high silica bauxite with lime
Each tonne of silica that dissolves from bauxite during digestion consumes approximately 1.2 tonnes of soda in forming DSP. It is generally considered uneconomic to treat bauxites containing greater than about 5% reactive silica by the conventional Bayer process because of excessive soda losses (O'Connor, 1988; Grubbs, 1987).Baksa et al. (1986) …
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Analysis of Bauxite Ore Beneficiation Methods
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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Leaching Kinetics of Thermally-Activated, High Silica Bauxite
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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Selective Processing of the Kaolinite Fraction of High …
Thus, by using preenrichment, it is possible to improve the quality of bauxite by separating high-silica (kaolinite) and high-iron materials. Additionally, the large amount of material released during enrichment results …
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Low-Temperature Treatment of Boehmitic Bauxite Using the …
The Bayer process is the main method of alumina production worldwide. The use of low-quality 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 high-pressure leaching at temperatures higher than …
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Mechanochemical treatment of high silica bauxite with lime
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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High Iron Diasporic Bauxite Processing Study
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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Extracting Silica and Alumina from Low-Grade Bauxite
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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Chemical Thermodynamics and Reaction Kinetics of Bayer Process
Since the Bayer process was patented in 1888 by Australian chemist Karl Bayer, this technology has been the major industrial process for the producing of alumina from bauxite ores [1, 2].Even after 135 years, this process remains unchanged for four major key sections: digestion of alumina-rich minerals (gibbsite, boehmite, and diaspore) into hot caustic solution, …
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