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Natural bauxite ore consists of aluminum hydroxide iron oxide titanium oxide and reactive silica the substances of which affect human health Aluminum hydroxide is the main content of the
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WO1998022390A1 Removal Of Silica From Bauxite 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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Crushed and washed bauxite ore must first go through a process to remove any silica found in the bauxite which would otherwise hinder the process and result in a product of lesser quality In a process known as digestion after any silica has been removed the remaining bauxite ore is combined with a hot caustic soda material in a heated pressure vessel in order to dissolve the aluminum
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Reduction of Reactive Silica from Bauxite Fernanda A N G Silva 1 Barbato C N 3 reduce the input of reactive silica into the process ii modify the process to produce a low soda
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Below the pisolitic bauxite horizon is a nodular ironstone layer At this level the bauxite becomes increasingly iron and kaolin rich Kaolinite which contains a great deal of silica is also much lower in aluminium content than bauxite Kaolinite tends to dissolve relatively easily in the caustic soda solution during aluminium extraction so
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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 % silica the minus 100 mesh fraction analysed a silica content as high as % The
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The first commercial extraction of alumina Al 2 O 3 from bauxite has been attributed to Henri Sainte Claire Deville in about 1854 production costs are much lower than when Boehmite or Diaspore are present The control of silica in the conventional Bayer Process is most important and in fact ores having reactive silica greater than 7% cannot be economically processed Unlike quartz which
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tated silica at 75°C Keywords bauxite reaction residue silica extraction amorphous silica sodium silicate 1 Introduction Poly aluminum chloride PAC is the most widely used inorganic polymercoagulant for water treatment because of its high adsorption activity wider pH working range pH 5 9 no need to add auxiliary agent and a lower
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In general the lower the Al2O3 content of the bauxite the larger the volume of red mud that will be generated as the non Al2O3 phases are rejected as red mud In addition the higher the kaolinite or reactive silica content of the bauxite the more red mud will be generated The reactive silica content not only increases the volume of red mud but also consumes caustic soda reagent and
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combined silica and which are considered economically mineable now or in the foreseeable future Table 12 shows some of the main minerals present in bauxite deposits The first commercial alumina AI20 3 extraction from bauxite was attributed to Henri Sainte Claire Deville3 about 1854 whereupon the price of aluminium quickly tumbled to a thirtieth of its price This method soon gave way to
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Testing at Bouba also found that the coarse component of the conglomerate bauxite formed % of the mass total in the high grade ores tested The high grade samples showed the average alumina grade increased by % while the average silica grade decreased by %
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Bauxite is a sedimentary rock with a relatively high aluminium content It is the world s main source of aluminium and consists mostly of the aluminium minerals gibbsite Al OH 3 boehmite γ AlO OH and diaspore α AlO OH mixed with the two iron oxides goethite FeO OH and haematite Fe 2 O 3 the aluminium clay mineral kaolinite Al 2 Si 2 O 5 OH 4 and small
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content and impurities such as silica Bauxites found in Weipa QLD typically contain around 50 per cent available alumina with relatively low silica content whilst the Darling Range WA bauxites contain only around 30 per cent available alumina and higher silica Alumina refineries endeavour to extract as much of the residual caustic as possible from the bauxite residue stream for reuse in the
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Global demand for industrial silica sand is expected to increase percent per year to 291 million metric tons in 2024 with a forecasted value of $ billion according to a new report from The Freedonia Group Constraining those gains will be efforts to use more recycled glass cullet in glass container manufacturing according to the report
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Your benefits withMAYA Online analyzers • Improved consistency of bauxite quality for alumina refineries • Optimized digester performance due to timely changes to the Bayer process chemistry • Increased refinery output • Reduced operating costs by savings in consumption of energy dissolving agents caustic soda lime • Reduced
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Beneficiation Machinery To Reduce Silica may 02 2024 beneficiation of bauxite email protected national metallurgical primary objective of the beneficiation process is to reduce the silica content in the ore as the latter reacts with caustic soda during the digestion step to jan 14 2024 natural bauxite ore consists of aluminum hydroxide
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The Page Description how to remove silica from iron ore how to reduce the silica content from manganese ore Know more The silica differential in the iron ore price is the discount buyers get according to silica content in the iron ore The 1 silica differential for iron ore cargoes with 60 Fe to 635 Fe fell to a historical low of 025/dmt July 8 from 150/dmt on January 7 according to
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Aug 12 2022Ore washing is the simplest and most effective method to improve the bauxite aluminum silicon ratio Generally the aluminum silicon ratio of bauxite can be doubled through ore washing which is more effective for the sorting of loose textured ore Washing is often combined with other sorting methods to improve recovery efficiency
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solid solution formation mullite formation from bauxite can reduce the effect of these impurities on the vitreous phase formation The objective of the present study is to explore the utiliza tion of Indian bauxite with considerable amount of impuri ties combined with silica sol to synthesize mullite Attempts have been made to investigate the effect of chemical com position of bauxite on
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EPA1 Removal of silica from bauxite Google Patents 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 contentWashing
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flotation method to reduce its silica content in the ore Therefore this study is aimed to utilize reverse flotation method to recover alumina content from washed bauxite tailing The reverse flotation experiments were carried out at pH of 6 and 8 while the particle sizes were varied at 140 270 mesh and 270 mesh using a batch and circuit configuration The result of this study shows that
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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 of Bauxite to Remove High Silica Content May 23 2024· In view of beneficiation action of bauxite removal of maximum silica
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This process reduces the amount of reactive silica in the bauxite fed to the Bayer process as well as removing a percentage of the inerts such as iron that contribute to red mud generation The result is a higher yield of alumina from the bauxite lower consumption of caustic soda and lower volumes of red mud generated The remaining low
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The concentration of crystalline silica was analyzed using FTIR spectroscopy Geometric mean respirable dust concentrations observed were and mg/m 3 for limestone iron and bauxite mines respectively similarly for crystalline silica concentration observations were and mg/m 3 respectively Among the three
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Low grade high silica bauxite has a relatively low alumina/silica A/S ratio so it must be desilicated prior to be used in the Bayer process digestion system [3 7] Among various desilication
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Both Bauxite nodes that I ve found so far are way up on the top of cliffs on some of the higher points on the map a transport the bauxite ore to lower elevation for pickup by truck or train via a considerable tower of vertical lifts b build a huge ramp to get a truck or train up to where the bauxite is
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Get started with a subscription today China s Aluminium Value Chain Quarterly Update is an independent and detailed assessment of the key metrics of China s bauxite alumina and primary aluminium industries as we see them presented in the form of an easily digestible set of charts and tables together with relevant commentary on
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To separate alumina from silica in bauxite ore associated with silica first the powdered ore is digested withoncentrated naoh solution at 473 523nd 35 36 bar pressure this results in the leaching out of alumina als sodium aluminate and silica sios sodium silicate leaving the impurities behind Get Price
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EP0950020A1 Removal of silica from bauxite Google Patents 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
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Australian Bauxite describes the bauxite as low silica and gibbsite rich with much of it suitable for use as a sweetener in alumina refineries The bauxite occurs on sparsely vegetated ridge tops on weathered Lower Tertiary volcanic tuffs In March 2024 Australian Bauxite published an initial Indicated Resource of Mt at % Al 2 O 3 and Inferred Resource of Mt at % Al 2
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