A process and its relating plant for thermal conversion of aluminum chloride hydrate into aluminum oxide and gaseous hydrogen chloride. In a first step, aluminum chloride hydrate is fed into a decomposition reactor where it is heated to a temperature between 120 and 400° C. Afterwards, the partially decomposed aluminum chloride hydrate is finally calcined to aluminum oxide at a temperature between 850 and 1200° C. in a second reactor. The aluminum chloride hydrate is admixed with aluminum oxide in an intensive mixer with a mass ratio between 1:1 and 10:1 aluminum chloride hydrate to aluminum oxide for using a fluidized bed reactor as a decomposition reactor.

The invention describes methods for the production of a high purity aluminum salt solution via electrodialysis, and ultimately, the conversion of the high purity aluminum salt to high purity aluminum oxide.

The invention describes methods for the production of a high purity aluminum salt solution via electrodialysis, and ultimately, the conversion of the high purity aluminum salt to high purity aluminum oxide.

A process for extracting values from lithium slag comprising: (a) hydrothermally treating lithium slag with an aqueous solution of an alkaline compound at selected temperature and duration; (b) performing an ion exchange step on the alkaline treated lithium slag; and (c) recovering values selected from the group consisting of aluminium compounds, silicon compounds and compounds containing silicon and aluminium.

The invention describes methods for the production of a high purity aluminum salt solution via electrodialysis, and ultimately, the conversion of the high purity aluminum salt to high purity aluminum oxide.

A process is disclosed for the oxidation and thermal decomposition of metal chlorides, leading to an efficient and effective separation of nuisance elements such as iron and aluminum from value metals such as copper and nickel. In the first instance, oxidation, especially for iron, is effected in an electrolytic reactor, wherein ferrous iron is oxidised to ferric. In a second embodiment, the oxidised solution is treated in a hydrothermal decomposer reactor, wherein decomposable trivalent metal chlorides form oxides and divalent metal chlorides form basic chlorides. The latter are soluble in dilute hydrochloric acid, and may be selectively re-dissolved from the hydrothermal solids, thereby effecting a clean separation. Hydrochloric acid is recovered from the hydrothermal reactor.

A process for preparing high purity alumina from aluminium-bearing materials is provided. The process digesting an aluminium bearing material to provide an aluminium chloride liquor, a first crystallisation vessel for crystallising aluminium chloride hexahydrate solids from the aluminium chloride liquor, optionally one or more subsequent crystallisation vessels for dissolving and recrystallising the aluminium chloride hexahydrate solids, and thermal treatment means for thermally treating the aluminium chloride hexahydrate solids to provide high purity alumina.

A process for preparing high purity alumina from aluminium-bearing materials is provided. The process digesting an aluminium bearing material to provide an aluminium chloride liquor, a first crystallisation vessel for crystallising aluminium chloride hexahydrate solids from the aluminium chloride liquor, optionally one or more subsequent crystallisation vessels for dissolving and recrystallising the aluminium chloride hexahydrate solids, and thermal treatment means for thermally treating the aluminium chloride hexahydrate solids to provide high purity alumina.

The invention pertains to methods of producing aluminum trioxide in the form of powders or agglomerations with particles having a porous honeycomb structure, which can be used as catalyst substrates, adsorbents and filters for the chemical, food, and pharmaceutical industry. The method of production of aluminum oxide in the form of powders or agglomerations with particles having a porous honeycomb structure involves the treatment of the aluminum salt with a solution of an alkaline reagent, washing of the sediment and thermal treatment thereof. The technical result of the invention is the production of aluminum oxide in the form of separate particles with given structure and properties, specifically, with particle porosity of 60-80% and a porous structure represented by extensive parallel channels with near hexagonal packing, with dimension of the channels at the diameter of 0.3 to 1.0 micron and length up to 50 microns. For this, the aluminum salt used is crystals of aluminum chloride hexahydrate, which are treated with an excess aqueous solution of ammonia at temperature of 20-80 C. to form boehmite, and the heat treatment is done at 450-650 C. until aluminum oxide is formed.

A process for alumina and carbonate production from aluminium rich materials with integrated CO.sub.2 utilization, comprising: comminuting and leaching Al-rich materials in concentrated HCl; separating unreacted material from metal chloride solution; separating Al.sup.3+ from solution by crystallization of AlCl.sub.3.6H.sub.2O; calcination of AlCl.sub.3.6H.sub.2O with HCl recovery; precipitation of metal carbonates from CO.sub.2; regeneration of HCl and extractive amines; the Al.sup.3+ 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 Al.sub.2O.sub.3; for precipitating metal carbonates, mixing the metal chloride solution with an organic solution containing a selected amine and contacting the mixture with a CO.sub.2-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.