Process for the production of high purity lithium hydroxide
Patent 4036713 Issued on July 19, 1977. Estimated Expiration Date: 
July 19, 1994. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
July 19, 1994. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References3438879 InventorAssigneeApplicationNo. 05/663851 filed on 03/04/1976US Classes:205/536Treating electrolyte or bath material prior to synthesis other than heating, cooling, or replacing consumed material during synthesisExaminersPrimary: Andrews, R. L.Attorney, Agent or FirmAbstractA process is described in which a brine from natural or other sources, containing lithium and other alkali and alkaline earth metals primarily as the halides, is preliminarily concentrated to a lithium content of about 2 to 7% to separate most of the alkali and alkaline earth metals other than lithium by precipitation, the pH of such a concentrated brine is then increased to about 10.5 to about 11.5, preferaly utilizing a product of the process, lithium hydroxide to precipitate substantially all of any remaining magnesium contaminants, and adding lithium carbonate to remove the calcium contaminants to provide a purified brine which is electrolyzed as the anolyte in a cell having a cation selective permeable membrane separating the anolyte from the catholyte, the latter being of water or aqueous lithium hydroxide, whereby the lithium ions migrate through the membrane to form substantially pure aqueous lithium hydroxide in the catholyte, a product from which highly pure lithium crystalline compounds such as lithium hydroxide monohydrate or lithium carbonate may be separated. |
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