Sintering Alumina: Effect of Atmospheres

The effect of trapped atmosphere on closure of pores was determined from apparent density limits obtained at high sintering temperatures and long sintering times. The complete elimination of porosity during sintering of alumina was possible if discontinuous grain growth was controlled and if the ambient atmosphere was hydrogen, oxygen, or vacuum.

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Comprehensive Extraction of Silica and Alumina from High …

2021-9-29 · This paper describes a novel process, hematite involved roasting − alkaline leaching − Bayer digestion, to extract silica and alumina from high-alumina coal gangue (HACG). The phase transformations during roasting were investigated through X-ray diffraction, X-ray photoelectron spectroscopy, scanning electronic microscope, and energy-dispersive …

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(PDF) Studying the Efficiency of Lime-Soda …

The three processes commonly used for extraction of alumina from clays are; (1) the acid leaching with sulfuric acid, hydrochloric acid or nitric acid to extract the alumina from calcined clay 18 ...

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Extraction of alumina from high-alumina coal ash using an …

2019-6-25 · The extraction rate of alumina was as high as 82.4%. Compared to the sintering and acid methods, the alkali hydrothermal method has the advantages of moderate energy saving, cleanliness and efficiency, and low equipment requirements; however, there are also shortcomings of excessive alkali circulation and the high causticity ratio of the ...

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Study on sintering process of raw materials in extracting …

2007-7-15 · ETDEWEB / Search Results / Study on sintering process of raw ... 20 FOSSIL-FUELED POWER PLANTS; FLY ASH; SINTERING; RAW MATERIALS; ALUMINIUM OXIDES; LIMESTONE; PARTICLE SIZE; CHEMICAL COMPOSITION; LEACHING; TIME DEPENDENCE; COMMINUTION; CALCIUM OXIDES; MATERIALS RECOVERY; DEMETALLIZATION; …

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Process and Mechanism of Alumina Extraction from High …

Process and Mechanism of Alumina Extraction from High-alumina Fly Ash by Ammonia MethodCN

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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 stage. The sinter mixes have been fired isothermally in air in the ...

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?EXTRACTION OF ALUMINA FROM NEPHELLINE SYENITE …

1996-2-19 · Nepheline Syenite of Koga (Lower Swat area) Pakistan was sintered at 125°C with suitable quantity of lime- stone followed by water leaching for the formation of alkali abuminates which are further processed for the extrac- tion of alumina. Parameters such as particle size variation, ratio of nepheline syenite and limestone, time tempera- ture of sintering and sodium …

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Alumina % and alumina extraction % from sintering.

Download scientific diagram | Alumina % and alumina extraction % from sintering. from publication: Studying the Efficiency of Lime-Soda Sinter Process to …

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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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Numerical Simulation of Sintering of DLP Printed Alumina …

A high-solid-loading alumina slurry with suitable rheological and photopolymerisable characteristics for DLP was created. TGA/DSC analysis was used to estimate thermal debinding parameters. The sintering process of the debound parts was studied by employing a numerical model based on thermo-viscoelasticity theory to describe the sintering process.

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(PDF) EXTRACTION OF ALUMINA FROM IRAQI COLORED …

In this work lime-sinter method was investigated to recover alumina from Iraqi colored kaolinitic claystone. The claystone was intimately mixed with limestone and the mixture was sintered. The annealed sintered material dusts to a fine powder which

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Spark Plasma Sintering of Alumina

A systematic study of various spark plasma sintering (SPS) parameters, namely temperature, holding time, heating rate, pressure, and pulse sequence, was conducted to investigate their effect on the densification, grain-growth kinetics, hardness, and fracture toughness of a commercially available submicrometer-sized Al 2 O 3 powder. The obtained experimental data …

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Alumina extraction technology from coal-measures kaoline ...

Alumina extraction technology from coal-measures kaoline by Sintering method of limestoneChinese Full Text REN Gen-kuan and ZHANG Ke-jian(1 partment of Chemical Engineering,Yibin University,Yibin 644007,China;2 ner Mongolia University of Technology,Hohhot 010051,China)

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lime sintering for alumina production process

Method for Alumina Extraction Desilication Coal Fly. Keywords Acid Process Alumina Production 3 4 or lime sintering 5 7 process which can generates a considerable amount of calcium silicate residue but iscined in lime production Lime in sintering charges solidifies immediately after mixing of the charge when milk of lime is crystallization process low lime sintering alumina and …

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EXTRACTION OF ALUMINA FROM NEPHELLINE SYENITE …

Corpus ID: 139049615; EXTRACTION OF ALUMINA FROM NEPHELLINE SYENITE BY SINTERING WITH LIMESTONE @article{Khan1996EXTRACTIONOA, title={EXTRACTION OF ALUMINA FROM NEPHELLINE SYENITE BY SINTERING WITH LIMESTONE}, author={M. Wakil Khan and Muhammad Riaz and K. Khan}, journal={Pakistan journal of scientific and …

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Study on Extraction of Alumina from Sericite Phyllite

Alumina from sericite phyllite was extracted by the way of limestone self-pulverization sintering technique. The key technical processes, including self-pulverization sintering, clinker leaching reaction and the carbonation decomposition, were investigated systematically. The results showed that the main phases of pulverized clinker consisted of γ-C2S and C12A7, and the self …

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Sintering Alumina: Effect of Atmospheres

Two effects of atmosphere on the sintering of alumina powder compacts were investigated. Changing the oxidizing conditions during early-stage sintering measurements showed that, within the range −70°F dew point oxygen to −70°F hydrogen equilibrated with alumina, there was no observable effect on sintering rate.

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Extraction of alumina from aluminum dross by a non …

2021-7-10 · The aluminum dross (AD), which causes numerous problems of its management and disposal to environment is a useful resource to extract alumina. This study explains a novel process to extract highly pure alumina (Al 2 O 3) from AD at a high extraction rate without producing the residues and exhaust gases. An experimental set up was designed to ...

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Technology Process of Extraction of Alumina from Coal …

Using Kaolin as a raw material to extract alumina.The conditions of calcining activation of fly ash with fluorite as assistant and extracting alumina were studied,the effects of conditions of calcining activation and leaching on the leaching rate of alumina from fly ash were investigated.The experimental results show that the conditions of calcining activation were obtained as: dosage …

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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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What is Alumina ceramic sintering

Liquid sintering can reduce the sintering temperature and promote the densification, Al2O3 content range is generally 80% to 99%, the material contains grain boundary glass phase or other phase. 2.Solid phase sintering. Solid-phase sintered alumina is a single-phase ceramic made of high-purity ultra-fine alumina powder.

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Alumina extraction technology from coal-measures …

Using kaolin as a raw material to extract alumina can reduce the cost,improve additional value and economic efficiency in a large scale.The conditions of calcining activation of fly ash with fluorite as assistant and extracting alumina were studied,the effects of conditions of calcining activation and leaching on the leaching rate of alumina from fly ash were investigated.The …

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EXTRACTION OF ALUMINA FROM IRAQI COLORED …

2019-9-22 · In this work lime -sinter method was investigated to recover alumina from Iraqi colored kaolinitic claystone. The claystone was intimately mixed with limestone and the mixture was sintered. The annealed sintered material dusts to a fine powder which required no grinding. This material was leached with sodium carbonate solution, and an alumina extract (sodium …

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Preparation of Alumina from Aluminum Ash by Sintering …

Aluminum ash is an industrial waste residue produced during alumina electrolysis and aluminum processing and casting. In the experiment, alumina powder with a purity of 98.97% was prepared by sintering with sodium hydroxide and the process conditions affecting the dissolution rate of Al 2 O 3 from aluminum ash were studied. The best process conditions for the dissolution of Al 2 O …

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Table 3 from EXTRACTION OF ALUMINA FROM IRAQI …

Corpus ID: 53965874. EXTRACTION OF ALUMINA FROM IRAQI COLORED KAOLIN BY LIME-SINTER PROCESS @inproceedings{Wahab2014EXTRACTIONOA, title={EXTRACTION OF ALUMINA FROM IRAQI COLORED KAOLIN BY LIME-SINTER PROCESS}, author={A. Wahab and A. Al-Ajeel and Suhair Z. Abdullah and Wasan A. Muslim and Malath Q. Abdulkhader and …

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Extraction of Alumina from Red Mud by Divalent Alkaline …

A novel method for extraction of alumina from red mud using a divalent alkaline earth metal oxide soda ash sinter process followed by thermo chemical leaching in suitable caustic concentration at 105 o C for different times is presented in this paper. During sintering Sodalite/Cancrinite, Gibbsite and Boehmite in red mud is converted to sodium aluminate as well as stable phases of divalent ...

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Study on sintering process of raw materials in extracting alumina …

Extraction of alumina from kaolin by a combination of pyro

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Alumina extraction technology from coal-measures …

Alumina extraction technology from coal-measures kaoline by Sintering method of limestone REN Gen-kuan and ZHANG Ke-jian(1 partment of Chemical Engineering,Yibin University,Yibin 644007,China;2 ner Mongolia University of Technology,Hohhot 010051,China)

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Extraction of alumina from alumina rich coal gangue by …

2020-4-28 · Alkali process primarily contains sintering and hydro-chemical process. In the sintering process, alumina-containing materials are mixed with limestone and sintered, transforming silica into dicalcium silicate and alumina into calcium aluminate. Then, alumina can be separated from silica efficiently in followed sodium carbonate leaching process ...

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Extraction of Alumina from Colored Kaolin by Lime-Soda …

2021-3-18 · shows the main effect of sintering variables on the Al 2 O 3 extraction%. A main effects plot is a plot of the means of the response variable for each level of a factor.

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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 CaO·Al 2 O 3, 12CaO·7Al 2 O 3 and 4CaO·Al 2 O 3 and SiO 2 as 2CaO·SiO 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 …

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Extraction of alumina from Hat Creek coaly waste by the …

Made available by U.S. Department of Energy Office of Scientific and Technical Information ...

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[PDF] EXTRACTION OF ALUMINA FROM IRAQI COLORED …

In this work lime -sinter method was investigated to recover alumina from Iraqi colored kaolinitic claystone. The claystone was intimately mixed with limestone and the mixture was sintered. The annealed sintered material dusts to a fine powder which required no grinding. This material was leached with sodium carbonate solution, and an alumina extract (sodium aluminate solution) …

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