Refining of lithium-containing aluminum scrap
AssigneeAlcan International Limited
InventorErnest W. Dewing
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Abstract
A method of refining lithium-containing aluminum scrap metal. An electrolytic cell is formed using molten scrap as the anode, lithium or Al-Li as the cathode and a chloride-based lithium electrolyte. The cell is operated at a temperature of about 700.degree. C. and the lithium is transferred from the scrap to the cathode. The depletion of lithium in the scrap is signalled by an abrupt rise in voltage of the cell. The remaining scrap at the anode can be used in the same way as conventional aluminum scrap and the pure Li or Al-Li alloy formed at the cathode can be used as new material for the Al-Li alloy market.
Claims11
A method of refining lithium-containing aluminum scrap to produce substantially pure Li and lithium-depleted scrap, which method comprises electrolyzing the lithium in an electrolytic cell employing said scrap in molten form as an anode, molten lithium as a cathode and a lithium chloride-based electrolyte, and collecting lithium from the cathode and lithium-depleted scrap from the anode.
A method of refining lithium-containing aluminum scrap, which comprises electrolyzing the lithium in an electrolytic cell employing said scrap in molten form as an anode, lithium or Li-Al alloy in molten form as a cathode and a lithium chloride-based electrolyte, monitoring the cell voltage as the electrolysis proceeds and terminating the electrolysis approximately when an abrupt rise in voltage corresponding to a depletion of lithium at the anode is observed.
Dependencies are inferred from the claim text.