摘要:
A process for alumina and carbonate production from aluminium rich materials with integrated CO2 utilization, comprising: comminuting and leaching Al-rich materials in concentrated HCl; separating unreacted material from metal chloride solution; separating Al3+ from solution by crystallization of AlCl3.6H2O; calcination of AlCl3.6H2O with HCl recovery; precipitation of metal carbonates from CO2; regeneration of HCl and extractive amines; the Al3+ separation the facilitated by increasing HCl concentration; the calcination being performed in two steps, one in the range 400 and 600° C. to generate a HCl-rich gas and one above 600° C. to produce Al2O3; for precipitating metal carbonates, mixing the metal chloride solution with an organic solution containing a selected amine and contacting the mixture with a CO2-containing gas, thereby also extracting HCl by formation of an ammonium chloride salt complex; processing thermally or chemically the organic solution to regenerate the amine for recirculation.
摘要:
The subject matter of the invention is a process for producing aluminum oxide, characterized by the following steps
(1) extracting aluminum ions with an organic solvent containing one or more compounds selected from the groups of alkyl phosphoric acids, alkyl and aryl thio phosphoric acids, carboxylic acids and hydroximes together with a petroleum hydrocarbon as a diluent; (2) preparing aluminum compounds containing fluorine by stripping the aluminum ions contained in the organic solvent of step (1) by contacting the organic solvent with an aqueous solution containing one or more compounds selected from the groups of HF, NH 4 HF 2 , NH 4 F or KHF 2 and simultaneously regenerating the organic solvent; and (3) producing aluminum oxide by heating the aluminum compounds containing fluorine resulting from step (2) in a gas stream containing oxygen or H 2 O.
摘要:
Nouveau procédé continu d'obtention d'alumine pure comprenant en combinaison nouvelle, l'attaque chlorosulfurique (B) de minerais alumineux calcinés contenant des impuretés, suivie d'une concentration de la liqueur obtenue après attaque et séparation des stériles (S 2 ), le traitement sulfurique de la liqueur concentrée, puis sa chloruration (G) provoquant la précipitation de la quasi-totalité du chlorure d'aluminium hexahydraté, la séparation du précipité de chlorure d'aluminium hexahydraté (Se) et de la liqueur-mère chlorosulfurique (L6) chargée en impuretés, la pyrohydrolyse du précipité donnant l'alumine pure recherchée avec recyclage de l'acide chlorhydrique, le dégazage (K) de la liqueur chlorosulfurique d'impuretés avec recyclage de l'HCI gazeux en chloruration (G) et l'obtention d'une liqueur sulfurique d'impuretés (L 11), enfin l'élimination des impuretés présentes dans cette dernière liqueur sous forme d'une précipitation sulfurique par concentration (L) en présence d'ions potassium.
摘要:
Disclosed herein, is a process for recovering- valuable metals and/or their oxides from red mud bauxite residues or similar. The process comprises: calcining a red mud residue having a pH of less than about 10 to provide a calcinated red mud residue; acid leaching the calcinated red mud residue to provide a silica rich solid component and an acid leachate; separating the silica rich solid component and the acid leachate; precipitating an iron rich solid component from the acid leachate; and separating the precipitated iron rich solid component from the acid leachate to provide an aluminium rich liquor.