Obtenção de galio a partir de rejeitos industriais

AUTOR(ES)
DATA DE PUBLICAÇÃO

1990

RESUMO

The gallium international demand has been increasing in the last few years, tending to grow, due to its application in assembling state of art eletronic devices, used in telecomunication, computers, etc. This element is found, in nature, very spread and, at low concentration. Among many methods used to concentrate it, there is the carbonatation process of the residual liquor from aluminium plant. It forms a precipitate that contains between 0,4 and 0,5 % of Ga2O3. In the present work, a study of extraction and re-extraction of this element was made, from the residual liquor of the bauxite treatment, from an aluminium plant. One of the biggest problems found was the great amount of aluminium present in the liquor towards the gallium one. A significative increase of the amount of gallium, at the final product was obtained. Gallium was extracted in the form of tetrachlorogallate associated with rhodamine B in an organic solvent, benzene/etil acetate 3:1 v/v. Gallium is then re-extracted with a basic aqueous solution, forming Ga(OH)4, and is finally recovered, by water destilation, in the oxide-hidroxyde form. The determined amount (18 %) of this element in the solid obtained shows porcentages significatively higher then that obtained by the carbonatation process. Besides aluminium, other metalic ions were detected at trace levels. This solid, at his crude form, is easely solubilized in alkaline solutions, being able to be eletrolized. All the process, since the liquor treatment until the solid containing gallium was made in a continuous system, permiting the recovery of the reagents easely.

ASSUNTO(S)

galio residuos industriais

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