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Beneficiation of bauxite the removal of silica in bauxite ore through screening at 20 mesh size where only 50 bauxite is the loss However they may have to go down to 10 mesh or 1j8 coarser sizes because of difficulties of blind ing of screens etc at 20 mesh but then he men tioned … Read More
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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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Beneficiation of High Silica Bauxite Ores of India an 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
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Caustic losses occur in processing high silica bauxite account for more than 20% of the alumina production costs Minimising caustic losses and maximising alumna yield were attempted to reduce the cost for processing low grade bauxite high in reactive silica This review paper summarizes the three major techniques developed for high silica
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Therefore leaching of bauxites with the silicate bacteria is expected to lower their silica content Subgrade bauxite deposits from Greece and Italy will be used in this study The work to be carried out involves the partial removal of silica from bauxite ores by means of microorganism assisted leaching The bauxite ores to be studied are
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Removal Of Silica From Bauxite 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 اGet Price
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SHANGHAI Dec 15 SMM As of December 13 the bauxite prices with an alumina to silica ratio of and an alumina content of 58% in Jinbei county of Shanxi stood at 400 450 yuan/mt including value added tax VAT excluding resource tax on a delivery to factory basis And the bauxite prices in Xiaoyi city of Shanxi stood at 430 475 yuan/mt
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The silica distribution in the 20 mesh fraction was as shown in Table II 41Reasons For Bauxite Beneficiation Hatch Ltd Due to the high grade of reactive silica in the Brazilian bauxite ores the Brazilian mines have included a beneficiation plant to reduce the reactive silica prior to the refinery by removing the finer fraction China it is reported that bauxite ore with the
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Reduce the input of reactive silica to the process This could take the form of beneficiation which may be preceded by a pre treatment to allow separation of silica from the bauxite or some other form of pre treatment that effectively renders the silica unreactive during the subsequent Bayer digestion 2
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In the process of FIG 1 bauxite 10 is supplied to a silica dissolution vessel 12 where the bauxite 10 is mixed with pregnant liquor 14 from the bauxite digestion step In silica dissolution vessel 12 the pregnant liquor 14 acts to dissolve a substantial portion for example approximately 90% of the reactive silica from the bauxite After a suitable residence time closely controlled to
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Bayer s Process Milling The bauxite is washed and crushed reducing the particle size and increasing the available surface area for the digestion stage Lime are added at the mill to make a pumpable slurry Desilication Bauxite with high levels of silica SiO2 go through this process to remove this impurity Silica can affect the quality
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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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Concentration of bauxite fines via froth flotation SciELO The tailings still contain bauxite which can be separated by reverse froth flotation flotation of the quartz and depression of the bauxite using starch as a depressant Insoluble silica grade there must be a minimum grade under which desilicification becomes problematic if the grade is too high the silica also dilutes the nbsp
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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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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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PDF Reduction of Reactive Silica from Bauxite The first fraction corresponded to crystallized bauxite CB commercially exploited by industry whereas the other one corresponded to crystallized amorphous bauxite CAB a marginal bauxite unprofitable to the Bayer process due to its high contents of reactive silica with particle size lower than 100 mm Samples were submitted to a study
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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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Removal Of Silica From Bauxite dry beneficiation of bauxite ore for removal of silica to reduce the silica content in the ore as the latter tions for the removal of the lower grade of fines beneficiation by dry screening the crushed bauxite at
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Beneficiation of bauxite email protected the bauxite to provide a desired quality of product a 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 precipitate out as insoluble sodium aluminium silicates
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how to reduce silica in bauxite 2024 02 11T03 02 56 00 00 How To Reduce Silica In Bauxite How To Reduce Silica In Bauxite This paper reports a study that implements reverse flotation method to separate silica from West Kalimantan bauxite ores The study is aimed to find the good process condition to obtain lowsilica bauxite as the feed for the Bayer process The experiments were carried out
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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 Read More PDF Reduction of Reactive Silica from Bauxite The lack of efficient processes to remove kaolinite t he greatest bearer of reactive silica
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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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These are i reduce the input of reactive silica into the process ii modify the process to produce a low soda residue and iii recover caustic soda by re processing residue For each 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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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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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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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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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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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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Choose from small filtration options like water bottles or purchase a home filter system 4 Bone Char Carbon Bone Char BC carbon is one of the oldest methods used to remove fluoride from water It is available in the form of water filter cartridges and can eliminate approximately 90% of the mineral content from water
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