Discharging waste water from the bauxite desilication process will bring potential environmental risk from the residual ions and organic compounds, especially hydrolyzed polyacrylamide. ... The PCR products of each sample were mixed to a final concentration of 20 pmol and then sequenced by MiSeq benchtop sequencer (Illumina, San Diego, USA) by ...
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Concentration of ore. The bauxite ore contains ferric oxide and silica as impurities. Gravity separation removes silica from crushed ore and magnetic separation separates ferric oxide impurities from the ore. The ore is then concentrated by a chemical process. Bauxite is the name given to aluminium ore.
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Bauxite residue is the byproduct of alumina production and is generated in the Bayer process when bauxite is digested in hot NaOH under elevated temperature and pressure. ... H 2 C 2 O 4 concentration, contact time and temperature had the most pronounced effect on the extracted Ga (ranging from to mg/kg while leaving the other factors ...
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The sulfur concentration was determined using a carbonsulfur analyzer. The chemical compositions of the mineral sample are shown in Table I. The mineral phase was analyzed via xray diffraction (XRD), and the results are shown in Fig. ... Sodium nitrate desulfurization was added to the Bayer process digestion of the highsulfur bauxite.
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The Bayer process is the main method of alumina production worldwide. The use of lowquality 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 highpressure leaching at temperatures higher than 220 °C.
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The REEs present in a bauxite ore end up in its bauxite residue during the Bayer process . The REE concentrations in the Jamaican bauxite residue is ppm . The average concentration of REEs in Greek karst bauxite residue is ca. 1000 ppm .
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An improved process for extracting monohydrate and trihydrate alumina from bauxite containing both forms of alumina. The slurry of bauxite is subjected to a first digestion in a first portion of spent liquor at conditions sufficient to extract the trihydrate. The liquor containing the dissolved trihydrate is separated from the slurry under conditions of temperature and pressure that are ...
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As an important industrial application material, alumina is mostly produced by Bayer process for the moment [].Because of the highgrade requirement of bauxite by Bayer process and the decreasing of global highquality bauxite resources year by year, it is urgent to develop new nontraditional bauxite resources and propose a new feasible production process [24].
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Concentration Definition: The process of removal of the gangue from Ore is known as Concentration or Dressing or Benefaction. There are numerous methods of concentration and the methods are chosen based on the properties of the ore. ... Extraction of the Aluminium metal from Bauxite ore is done using this process. Most of the large structures ...
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Keeping the above characteristics in view, several west coast lateritic bauxite mines of India employ dry crushing−screening process to bring down silica content from the metallurgical grade bauxite [].Recently, a bauxite mine of Guinea known as AGB2A has also adopted the dry beneficiation procedure to cut down silica from about 7% to below 3%, to make this one the best metallurgical grade ...
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In the EAF process, a mixture of bauxite residue and coal was smelted in an EAF at °C to form an iron alloy with more than 90 % ... The concentration of REEs in the slag sample was increased by a factor of about compared to the concentration of REEs in bauxite residue. Table 4 Major chemical components in the slag sample. Full ...
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(a) The process for concentration of bauxite ore is Bayer's process (In which an ore of aluminium which is bauxite is heated in a pressure vessel along with a solution of sodium hydroxide also known as caustic soda at a temperature of 150 to {200^o}C .
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Of this the greatest concentration is in Guinea, where there are wellproven resources of approximately 25 billion tonnes. Most bauxite occurs close to the surface, with only 1 or 2 m of overburden. Typical deposits range in thickness from 3 to 15 m. ... The bauxite ore, Bayer process materials before precipitation, ...
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Bauxite residue or red mud is a major byproduct of the aluminium industry, with an annual global production of 150 million t (Evans 2016) and a total inventory of billion t (Binnemans et al. 2013).The current best practice in the industry is disposal in engineered bauxite residue disposal areas or BRDA, increasingly using dry stacking methods with equipment such as Amphirols to aid ...
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The rate of its formation in digestion is principally related to the bauxite organic carbon concentration and composition, and to the conditions of time, temperature and the presence of oxygen and catalytic compounds under which they are processed. ... M. Hollitt, J. Kisler, B. Raahauge, The Comalco bauxite activation process, in Alumina ...
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Bauxite is a mixture of minerals which contain, as well as impurities, different concentrations of hydrated aluminium oxides. Gibbsite (alumina trihydrate), boehmite, and diaspore (alumina monohydrates) are the main ore minerals. Bauxite is a highaluminiumcontent rock. That is the main ore that aluminium is mined from.
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Why is leaching used as the method of concentration for bauxite ore? Medium. View solution > Write the process of producing alumina from bauxite. Medium. View solution > How is bauxite ore formed? Answer required. Hard. View solution > Bauxite ore is concentrated by. Medium. View solution >
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It is one of the critical contaminants in the Bayer process. Its average concentration, in karst bauxites is usually % and in laterite bauxite % in order of magnitude . Based on the available data the highest C org content, in deposit average, was revealed at Gove with value of % (Hill et al. 1983).
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The concentration of the Bauxite ore into alumina is done by Bayer's process. Alumina is then refined into pure aluminium metal through the HallHéroult electrolytic process. Aluminium is too high in the electrochemical series (reactivity series) to be extracted from its ore using carbon reduction.
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The Bayer process is used worldwide for the alumina production. This process involves the alkaline leaching of bauxite to extract Al, followed by the precipitation of Al(OH) 3 to recycle the solution [1,2,3].The leaching process results in the formation of a solid residue, commonly referred to as a bauxite residue, which consists of iron minerals, hydrous aluminosilicates, which are formed ...
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The correct option is D Leaching. Bauxite ore is concentrated by the process of leaching. It is a process in which a suitable solution is added to the ore. A chemical reaction takes place between ore and solution in which the ore dissolves in the solution. The insoluble impurities are filtered off.
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The lateritic bauxite hydrochloric acid leaching process showed that when the ore granularity was less than 55 μm, the liquid/solid ratio (L/S ratio) was 100:7, the leaching temperature was 373383 K, the leaching time was 120 min and the HCl concentration was 10%, both the leaching rates of Al and Fe were over 95% . But the hydrochloric ...
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Generally, 12 tons of bauxite residue generated while producing 1 ton of alumina mainly depending on the bauxite quality and production process (Zhao et al., 2009; Jones et al., 2012; Deihimi et al., 2018; Borra et al., 2015).According to the statistics of the International Aluminium Institute (Aluminium, 2019), Fig. 1 illustrated the world alumina production since the 21 st century and the ...
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For the same grade of bauxite ore, using the traditional Bayer process, the theoretical maximum alumina dissolution rate is % and the Na 2 O mass fraction in the slag is about % (A/S = 1 and N/S = in the red mud), while the actual dissolution rate of the Bayer process bauxite ore in this alumina plant is about 70%, which shows ...
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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. ... Conditions within the digester (caustic concentration, temperature and pressure) are set according to the properties of the bauxite ore. Ores with a high gibbsite content can be ...
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The process conditions are more aggressive for boehmite and diaspore owing to the complex dissolution (boehmite: 200240 °C, 1234 atm, and 140240 g/L of alkali concentration, diaspore: 220260 °C, 2834 atm, and 250280 g/L of alkali concentration) (Lyu et al., 2021).
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In this process, bauxite containing approximately 50 pct alumina and up to 15 pct silica is first treated by the American modification of the Bayer process, and the insoluble material, usually called red mud, is partially dewatered, mixed with limestone and soda ash, and sintered in rotary kilns. ... The caustic soda concentration and the ...
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eral concentration is achieved by different methods such as gravity separation, magnetic separation, froth flotation, etc. Bauxite Beneficiation The Bayer process is a wellestablished process for alumina extraction from bauxite, which makes use of caustic soda at high temperature. This method not only dissolves alumina
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In order to explore the commercialized applications of the lowgrade bauxite in the refractory industry, a calcination integrated with acid leaching method was adopted to remove the potassium (K) and iron (Fe) from the diasporeillite (DI) type lowgrade bauxite. Following calcining the bauxite at different temperatures, the leaching parameters, including the sulfuric acid concentration ...
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Crushed bauxite is treated with moderately concentrated sodium hydroxide solution. The concentration, temperature and pressure used depend on the source of the bauxite and exactly what form of aluminum oxide it contains. Temperatures are typically from 140°C to 240°C; pressures can be up to about 35 atmospheres.
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To systematically develop the REE recovery process from bauxite residue, three different leaching agents ... To determine the concentration of REEs in the bauxite residue sample, aqua regia ...
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Gibbsitic bauxite from Australia was leached by hydrochloric acid in this work. Analysis on kinetics for the extraction of Al 2 O 3 was quantitatively studied. It was concluded that the hydrochloric acid leaching process of gibbsitic bauxite was controlled by chemical reaction. Moreover, the mechanism for the dissolution followed the equation ...
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Dressing or Concentration of the Bauxite ore by Hall's method . The dressing is the process of extracting a metal from an ore in which gangue is removed and the ore is prepared for smelting, refining, or other processes. Ferric oxide and silica are normally present as impurities in bauxite. Bauxite ore is dressed by crushing and pulverizing.
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A material supplier from Belgium would like to produce limestone powder for his custome...
India is rich in various mineral resources and it is an important mineral processing market
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