lime sintering for alumina production process

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Lime-sinter process for production of alumina from fly ash ...

@article{osti_7365894, title = {Lime-sinter process for production of alumina from fly ash}, author = {Chou, K S and Kelmm, W A and Murtha, M J and Burnet, G}, abstractNote = {A substantial background of literature on methods of extracting alumina from aluminous-siliceous raw materials shows that alumina may be released by addition of calcium oxide (lime) in a high-temperature treatment to ...

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An Improved Lime Sinter Process to Produce Al2O3 from

The application of the lime sinter process is restricted by the high consumption of calcium, the large amount of slag and the poor alumina leaching property of clinkers. An improved lime sinter process based on the dry-sintering is proposed by adding Na 2 O-containing compounds to decrease CaO addition and increase alumina leaching property.

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(PDF) Studying the Efficiency of Lime-Soda Sinter Process ...

Figure 1: Flowchart of lime/soda sinter process for alumina production [12]. These balls were l eft to dry in air, and then dried in oven at a temperature of 150 °C for 2 hrs, to

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A Novel Process of Alumina Production from Low-Grade ...

2017-2-12  Soda-lime sintering process and lime sintering process are the research focus on utilization of low-grade alumina recently. The latter process can realize dry-sintering process and its energy consumption is relatively lower. However, its sintering temperature is up to 1350 °C, which is unfavorable to industrial production.

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(PDF) An Improved Lime Sinter Process to Produce Al2O3 ...

An improved lime sinter process based on the dry-sintering is proposed by adding Na2O-containing compounds to decrease CaO addition and increase alumina leaching

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Lime–Alumina–Silica processing incorporating minerals ...

1999-6-1  Thus, a reaction-sintering process as applied to a system such as alumina–kyanite should result in an alumina–mullite product. With respect to the reaction-sintering of alumina–wollastonite mixtures, previous investigations have suggested that the resulting material will ideally be composed of alumina–gehlenite–anorthite–hibonite.

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Sintering kinetics and alumina yield in lime-soda sinter ...

An investigation of the application of the lime-soda sinter process to alumina extraction from coal wastes has been carried out. In the sintering stage, the optimal operating conditions have been obtained for the highest yield of alumina. The kinetics of sodium aluminate formation have also been studied in the sintering

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Study and application of intensified sintering process for ...

The results show that 3CaO2SiO2, and 2CaOSiO2, are primarily formed in the sintering process when diasporic bauxite is sintered at soda ratio Na2O/ (Al2O3 +Fe2O3) of 1 and lime ratio CaO/SiO2 ...

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ARTICLE: Addressing the Challenge of Bauxite Residue ...

2019-3-11  A lime sintering process for production of alumina from boehmite and diaspore bauxites was developed for producing alumina from low grade bauxite in

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Improved Sintering Procedures for Aluminum P/M Parts ...

Abstract. This paper discusses sintering practices for the production of aluminum P/M parts in nitrogen and dissociated ammonia and in vacuum. The influence of sintering atmosphere, dew point and temperature on the mechanical properties and dimensions

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New developments in the lime-soda sinter process for ...

The efficiency of alumina recovery from coal fly ash by the lime-sinter process is improved by the addition of a small amount of coal cleaning refuse. Approximately 5.0 wt % refuse increases alumina recovery from 55% to 90% for subbituminous coal ashes and reduces the required sintering temperature from 1380 to 1200/sup 0/C. Mixtures of fly ash ...

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(PDF) An Improved Lime Sinter Process to Produce Al2O3 ...

An improved lime sinter process based on the dry-sintering is proposed by adding Na2O-containing compounds to decrease CaO addition and increase alumina leaching property.

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(PDF) Sintering process of diasporic bauxite with high ...

Sintering process of diasporic bauxite with high iron content at low ratio of lime to silica for alumina production October 2008 Zhongguo Youse Jinshu Xuebao/Chinese Journal of Nonferrous Metals ...

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Lime–Alumina–Silica processing incorporating minerals ...

1999-6-1  Thus, a reaction-sintering process as applied to a system such as alumina–kyanite should result in an alumina–mullite product. With respect to the reaction-sintering of alumina–wollastonite mixtures, previous investigations have suggested that the resulting material will ideally be composed of alumina–gehlenite–anorthite–hibonite.

More

Sintering kinetics and alumina yield in lime-soda sinter ...

An investigation of the application of the lime-soda sinter process to alumina extraction from coal wastes has been carried out. In the sintering stage, the optimal operating conditions have been obtained for the highest yield of alumina. The kinetics of sodium aluminate formation have also been studied in the sintering stage. The sinter mixes have been fired isothermally in air in the ...

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The Bayer Process-The Main Production Method of Alumina

2020-11-10  There are many methods for extracting alumina from ore, such as the Bayer method, soda-lime sintering method, Bayer-sintering combined method, etc. The Bayer Process has always been the main method for producing alumina, and its output accounts for about 95% of the world's total alumina output. Since the 1970s, the acid method has made great ...

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ARTICLE: Addressing the Challenge of Bauxite Residue ...

2019-3-11  A lime sintering process for production of alumina from boehmite and diaspore bauxites was developed for producing alumina from low grade bauxite in China and Russia. The process involves a pyro-metallurgical sinter approach, which produces aluminum while ”locking up” the silica as clinker, thus preventing it from contaminating the alumina.

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Method for Alumina Extraction Desilication Coal Fly Ash

2017-5-9  Keywords Coal fly ash; low-lime sintering; alumina extraction; Na 2CaSiO 4 1. Introduction Coal fly ash (CFA) is a by-product of coal combustion collected from coal-fired power plant during the high temperature process. More than 750 million tons of CFA was gener-ated per year globally [1]. For China, the annual CFA generation is still ...

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SUSTAINABILITY IN ALUMINA PRODUCTION FROM

2017-12-4  Figure 3: Flowsheet of material flow in Pedersen process for alumina production. SINTERING PROCESS In addition to the above processes, sintering process is also used for alumina production from bauxite. In this process, Na2CO3 is added to react with Al2O3 in bauxite at high temperatures i.e. 1000˚C and water-soluble NaAlO2 is formed.

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Extraction of alumina from kaolin by a combination of

2019-5-1  After the sintering process; the composition of the resulting material would contain Al 2 O 3 as CaOAl 2 O 3, 12CaO7Al 2 O 3 and 4CaOAl 2 O 3 and SiO 2 as 2CaOSiO 2.This means that for each mole of SiO 2 present in the kaolin there must be 2 mol of CaO added and approximately 1.8 mol of CaO for each mole of Al 2 O 3 and so on for other compounds. The equations below describe the ...

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Lime–Alumina–Silica processing incorporating minerals ...

1999-6-1  Thus, a reaction-sintering process as applied to a system such as alumina–kyanite should result in an alumina–mullite product. With respect to the reaction-sintering of alumina–wollastonite mixtures, previous investigations have suggested that the resulting material will ideally be composed of alumina–gehlenite–anorthite–hibonite.

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Alkali desilicated coal fly ash as substitute of bauxite in

2010-7-6  Alkali desilicated coal fly ash as substitute of bauxite in lime-soda sintering process for aluminum production BAI Guang-hui(白光辉)1, TENG Wei( 滕 玮)2, WANG Xiang-gang( 王香港)1, QIN Jin-guo(秦晋国)3, XU Peng(徐 鹏)1, LI Peng-cheng(李鹏程)1 ...

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EXTRACTION OF ALUMINA FROM IRAQI COLORED

of sintering temperature and time, concentration of sodium carbonate solution, leaching time and sintered powder to sodium carbonate solution were studieratio d. About 85% of the alumina in the claystone was extracted at the optimumconditions. The alumina obtained in this method assaying 98% Al 2O 3, 1.45% SiO 2, 0.04% Fe 2O

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Recovery of Alumina From Kaolin by the Lime-Soda Sinter ...

carbonate is recovered for use in the leaching step. The alumina tri-hydrate is calcihed to obtain alumina in a crystalline form suitable to be charged to the electrolytic cells used in the manufacture of aluminum. The requisite steps for the complete process, as shown

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The Sintering and Leaching of Low-Grade Diasporic

An improved lime-sintering process was developed to produce alumina from low-grade diasporic bauxite in this paper. Both clinkers sintered by the real bauxite and simulated bauxite at 1350 °C when the molar ratio of CaO to Al2O3 decreased to 1.4 were produced, the alumina leaching rates of which reached over 90% in sodium carbonate liquor. The main phases in the clinkers after sintering are ...

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Factors affecting on the extraction of alumina from kaolin ...

2021-7-1  The kaolin ore was processed using lime-sinter process by sintering kaolin-limestone charge in the temperature range 800 -1400⁰C for 1hr. Factors affecting the percent recovery of alumina from kaolin ore such as the briquetting pressure and the sintering temperature were investigated.

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Study on Recovering Iron and Alumina from Bayer Red

Finally soda lime sintering - dissolution - magnetic separation joint recovery of a preliminary economic analysis of the process of iron and aluminum. Processing 100 tons of dry red mud can produce 12.39 tons of alumina, 6.57 tons of sponge iron, 64.58 tons of calcium silicon slag, profitable 23,990.51 yuan, good economic returns, suitable for ...

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Low-Temperature Sintering of Alumina with Liquid

2019-2-4  optimal sintering time since longer time did not increase the density much. At 12OO0C, the sintering kinetics were so fast that a 99.1% density was reached in 15 min. However, the higher sintering temperature did not result in higher densities for sintering time longer than 1 h. The microstructure of a doped alumina (process B) sin-

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Solid state and phase transformation mechanism of kaolin ...

2020-10-1  The present work aims to investigate the effects of the solid-state thermal reactions at different sintering temperatures on the phase transformation mechanisms and the microstructural changes, the self-disintegration mechanism as well as the efficiency of alumina percent recovery during alumina extraction from kaolin by the lime-sinter process.

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Ceramics: Sintering and Microstructure

2018-8-23  Usually this is done by a sintering process ... For example during the production of ceramic layers, the porosity is not always ... (e.g. 3987 g/cm3 for alpha alumina) and on the closed pore volume (Vf) with essentially zero density (equation (4)). This means that the volume of the closed pores can be

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