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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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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Separation of silica from bauxite via froth flotation
This paper reports an innovative development: concentrating gibbsite via reverse froth flotation in order to obtain a metallurgical-grade bauxite concentrate. Tailings from an industrial plant have undergone attrition scrubbing and desliming; the quartz silica contained in the tailings has undergone flotation.Starch was used as a depressant, and ether-amine as the …
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The Sandy Desilication Product Process Concept | JOM
Reactive silica is the most detrimental impurity in bauxite. When bauxite is contacted with Bayer liquor, reactive silica dissolves and then precipitates as a sodium aluminum silicate known as the desilication product (DSP), which is discarded along with the bauxite residue and maintained in long-term storage facilities. DSP recycling using bauxite residue lime sinter …
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Mechanochemical treatment of high silica bauxite with lime
This paper reports the results of an initial study of the mechanochemical processing of bauxite/lime slurries. It is shown that for sufficiently high lime to bauxite ratios mechanical …
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High Grade Silica Quartz | Australian Silica Quartz Group Ltd
Bauxite Resources Ltd has incorporated and wholly owns the subsidiary company Australian Silica Quartz Pty Ltd. Australian Silica Quartz Group Ltd. ... quartz deposits in Western Australia and Queensland and the company is currently evaluating the potential to produce a high grade lump silica or hard rock quartz product.
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Removal of Silicon, Aluminum and Phosphorus …
high silica and alumina have adverse eff ects on the reducibility of the iron ore and sinter plant productivity. The specifications for iron grade and quantities of impurities in the commercial iron ores/ iron concentrates require above 60% Fe, below 5% (SiO2+Al2O3), and less than 0.1% P [3]. Thus, impurity removal from iron ore
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Characterization and Beneficiation Studies of a Low Grade Bauxite …
A low grade bauxite sample of central India was thoroughly characterized with the help of stereomicroscope, reflected light microscope and electron microscope using QEMSCAN. A few hand picked samples were collected from different places of the mine and were subjected to geochemical characterization studies. The geochemical studies indicated that most of the …
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The Processing of High Quartz Bauxite
Bauxite Specification. Characteristics of mud from Digested Bauxite. Development of Continuous Quartz Separation Process. Generic Design and Decision Making Process for …
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Bauxite Beneficiation: An Approach to Value Addition in …
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 …
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High silica bauxites
reactive silica compounds from the bauxite dissolve into the liquor and re-precipitate as soda containing "desilication products" (DSPs) which are generally discarded with the red mud waste.
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Chemical Thermodynamics and Reaction Kinetics of Bayer …
X = OH −, Cl −, SO 4 2− and CO 3 2−.. The principles of Bayer desilication have been described in many studies [7, 8].Impurities in bauxite dissolve and accumulate in the Bayer circuit, contributing to an array of process issues thus making it difficult to operate and control [] with silicate phases being a primary contributor.Silicates such as kaolinite, halloysite, …
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BENEFICIATION OF HIGH SILICA BAUXITE ORES OF …
BENEFICIATION OF HIGH SILICA BAUXITE ORES OF INDIA AN INNOVATIVE APPROACH ... it has been made possible to remove ~30% of silica with 92% recovery depending on the characteristics of the ore. The results ... The other common silicate mineral in bauxite ore is quartz. Karst bauxite has a different mineralogical composition than the lateritic
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Redalyc.Kaolinite removal from bauxite by flotation
and kaolinite are the main silica bearing minerals in Chinese ores. Kaolinite and quartz are the main silica bearing miner - als in Brazilian bauxites. Brazil holds two types of deposits. The bauxite reserves in the north region present high-grade of Al 2 O 3 and kaolinite is the main gangue mineral; the deposits from the central-south region ...
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SILICA REMOVAL FROM BAUXITES | | Project | Fact sheet
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.
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The Processing of High Silica Bauxites
When the mixture of the high-silica bauxite and Na2CO3 with mole ratio of Na2O/(Al2O3 + SiO2) of 1 was sintered at 950 °C for 30 min, diaspore and kaolinite were primarily converted into Na1 ...
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Pilot Tests with Tertiary Cyclone for Reactive Silica …
recovery of alumina and 45.9 % recovery of silica to product. Keywords: Bauxite beneficiation, Clay removal, Silica reduction, Hydrocyclones. 1. Introduction Bauxite is the main ore for production of metallic aluminum. Production is generally carried out by the Bayer process to form alumina, followed by the Hall-Héroult process to carry out the
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Separation of silica from bauxite via froth flotation
When low-grade high-silica bauxite undergoes desilication by alkaline leaching, a large amount of alkali-silicate solution will be produced. To realize its recycling, the alkali-silicate solution ...
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High Grade Silica Quartz | Australian Silica Quartz Group Ltd
Bauxite Resources Ltd has incorporated and wholly owns the subsidiary company Australian Silica Quartz Pty Ltd. ... are extremely diverse and there are a number of established and emerging markets for varying grades of silica sand and quartz products. High grade silica sands where the silica component is greater than 99.5% SiO 2 are used ...
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Selective Processing of the Kaolinite Fraction of High-Silicon Bauxite
Magnetic separation is mainly used for iron removal and rarely for silica removal . To improve the efficiency of magnetic separation, microwave energy was applied to magnetize the sintering of high-iron bauxite via iron shavings as a reducing agent . Magnetic sintering of the bauxite sample was carried out with the addition of 20–40% chips at ...
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High Grade Silica Quartz | Australian Silica Quartz Group Ltd
Silica (SiO 2) naturally occurs as the mineral quartz, or silica sand and is a major component of many igneous and sedimentary rocks. Silica can be found naturally in a number of forms - as a hard rock quartz vein or reef, as quartz pebbles, or as sandstone, quartzite, or as sand.
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Mechanochemical treatment of high silica bauxite with …
It is shown that for sufficiently high lime to bauxite ratios mechanical milling results in the removal of silica from bauxite via the formation of an iron substituted hydrogarnet phase. The hydrogarnet phase is found to be stable under the Bayer digestion …
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Process Simulation with Tertiary Cyclone for Kaolinite Removal …
More than 80% of Paragominas' bauxite is processed in hydrocyclones, equipment that presents a relative low classification efficiency regarding the presence of fine particles on the coarser flow being carried by respective water partition [].As a solution to mitigate this factor, the current plant design is composed of classification circuits in two sub-steps, where the …
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Beneficiation of High Silica Bauxite Ores of India an …
The other common silicate mineral in bauxite ore is quartz. Karst ... high silica bauxites is the loss of caustic soda from the recirculating Bayer liquor. To address these issues, Vedanta ... the removal of silica, reactive silica and iron values from the given sample. The physical and chemical properties of the sample
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Extracting silica and alumina from low-grade bauxite
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 Institute, St. Petersburg, pilot plant with …
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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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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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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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Reaction Behavior of Aluminogoethite and Silica Minerals in …
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 ...
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Bauxite
wet or dry) to remove the fine grained material to improve the grade and/or handleability. These deposits usually have a beneficiation plant that washes the bauxite and sends the high silica fines (kaolinite and/or quartz) to a tailings dam prior to ship loading the bauxite. Karstic bauxite Lateritic bauxite Global distribution of bauxite
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