Process for producing alumina and a lithium salt
AssigneeTianqi Lithium Kwinana Pty Ltd
InventorsYafeng Guo, Hazel Lim
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Abstract
A process for producing alumina and a lithium salt comprising the steps of: (a) calcining an alpha spodumene ore or concentrate to produce beta spodumene; and (b) (I) leaching beta spodumene from the calcining step (a) with an alkaline solution under pressure; or (II) sulphating beta spodumene with at least sodium sulphate and leaching said sulphated beta spodumene to produce a lithium containing solution and a zeolitic residue. The lithium containing solution is treated to provide a purified lithium salt and said zeolitic residue is treated to provide high purity alumina.
Claims20
A process for producing alumina and a lithium salt comprising the steps of:
- (a) calcining an alpha spodumene ore or concentrate to produce beta spodumene;
- and
- (b) (I) leaching the beta spodumene from the calcining step (a) with an alkaline solution under pressure;
- or
- (II) sulphating the beta spodumene with at least sodium sulphate to produce sulphated beta spodumene and leaching said sulphated beta spodumene,
- to produce a lithium containing solution and a zeolitic residue wherein said lithium containing solution is treated to provide a purified lithium salt and said zeolitic residue is treated to provide alumina,
- wherein said zeolitic residue is treated by the following steps:
- (i) acid leaching said zeolitic residue with an acid selected from the group consisting of hydrochloric acid and sulphuric acid,
- (ii) intermediate neutralisation;
- (iii) acid leaching involving hydrochloric acid to form an aluminum chloride hexahydrate (ACH) solution;
- and
- (iv) treating said ACH solution to provide α-phase alumina.
A process for producing alumina and a lithium salt comprising the steps of:
- (a) calcining an alpha spodumene ore or concentrate to produce beta spodumene;
- and
- (b) (I) leaching the beta spodumene from the calcining step (a) with an alkaline sodium sulphate solution under pressure to produce a lithium sulphate containing solution and a zeolitic residue;
- or
- (II) sulphating the beta spodumene with at least sodium sulphate to produce sulphated beta spodumene and leaching said sulphated beta spodumene to produce a lithium sulphate containing solution and a zeolitic residue,
- treating said lithium sulphate containing solution to provide a purified lithium salt,
- wherein said zeolitic residue is separated from the lithium sulphate containing solution and treated to provide α-phase alumina by the following sequence of steps:
- (i) acid leaching the zeolitic residue to form a silica enriched solid by product and an aluminum containing solution containing impurities including sodium introduced by step (b);
- (ii) neutralising the aluminum containing solution by intermediate neutralisation to precipitate an aluminum hydroxide and form a waste solution containing sodium;
- (iii) separating the aluminum hydroxide from the waste solution containing sodium thus separating the aluminum hydroxide from the waste solution containing sodium;
- (iv) leaching the aluminum hydroxide with hydrochloric acid to form an aluminium chloride solution;
- (v) precipitating aluminum chloride in the form of crystallised aluminum chloride hexahydrate (ACH) from the aluminum chloride solution of step (iv);
- and
- (vi) treating said crystallised ACH to provide the α-phase alumina;
- and
- wherein sodium sulphate is regenerated by contacting the lithium sulphate containing solution with sodium hydroxide to produce a lithium hydroxide solution and sodium sulphate, the regenerated sodium sulphate being re-used in step (b).
Dependencies are inferred from the claim text.