Precipitation Area Upgrade at ETI Aluminum

Çelikel, Bekir; Demîr, Gökhan Kürsat; Kayacı, Murat; Baygul, Meral; Cuevas‐Suárez, Carlos Enrique

doi:10.1002/9781118359259.ch23

Cited by 4 publications

(1 citation statement)

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“…Then, the supersaturated alkaline aluminate liquor can enter a precipitation stage, where gibbsite (Al(OH) 3 ) precipitates out in the presence of a large number of seed crystals (to achieve that, the ratio of Al 2 O 3 in the liquor to that in the seed crystals must be greater than 4). To obtain coarse particles of Al(OH) 3 (only 10% of particles should have a size below 45 µm) and a precipitation rate of more than 50% required for SGA production, the duration of the whole process should be 48-72 h [50]. Therefore, in order to produce SGA that suits the required standards, the use of high-pressure equipment and large decomposers, as well as additional energy and raw materials, is required, which significantly increases the cost of the final product.…”

Section: Sga Production From Amorphous Aluminamentioning

confidence: 99%

Acid and Acid-Alkali Treatment Methods of Al-Chloride Solution Obtained by the Leaching of Coal Fly Ash to Produce Sandy Grade Alumina

Valeev

Shoppert

Михайлова

2020

Metals

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Sandy grade alumina is a valuable intermediate material that is mainly produced by the Bayer process and used for manufacturing primary metallic aluminum. Coal fly ash is generated in coal-fired power plants as a by-product of coal combustion that consists of submicron ash particles and is considered to be a potentially hazardous technogenic waste. The present paper demonstrates that the Al-chloride solution obtained by leaching coal fly ash can be further processed to obtain sandy grade alumina, which is essentially suitable for metallic aluminum production. The novel process developed in the present study involves the production of amorphous alumina via the calcination of aluminium chloride hexahydrate obtained by salting-out from acid Al-Cl liquor. Following this, alkaline treatment with further Al2O3 dissolution and recrystallization as Al(OH)3 particles is applied, and a final calcination step is employed to obtain sandy grade alumina with minimum impurities. The process does not require high-pressure equipment and reutilizes the alkaline liquor and gibbsite particles from the Bayer process, which allows the sandy grade alumina production costs to be to significantly reduced. The present article also discusses the main technological parameters of the acid treatment and the amounts of major impurities in the sandy grade alumina obtained by the different (acid and acid-alkali) methods.

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Section: Sga Production From Amorphous Aluminamentioning

confidence: 99%