Patent ID: 8551319
Filing Date: 2013-10-08
Classification: C04B,C25C

Abstract:
1. A process for the preparation of potassium metal starting from potassium amalgam by electrolysis using a potassium amalgam-containing anode, a potassium ion-conducting solid electrolyte and liquid potassium metal as the cathode, wherein a solid polycrystalline potassium ion conductor having a β″-Al 2 O 3 structure obtainable by means of ion exchange of the alkali metal ions of a polycrystalline alkali metal β″-Al 2 O 3 moulding, in which the alkali metal ions are sodium ions or a mixture of sodium and potassium ions and the molar ratio M 2 O (M=alkali metal) to Al 2 O 3 is 1:x, x being an integer or non-integer number within the range 5 to 11, for potassium ions, the ion exchange being effected by a process wherein neither chloride-containing nor liquid potassium ion sources are used, the process comprising the steps of: embedding the polycrystalline alkali metal β″-Al heating the embedded moulding at a rate of at least 100° C. per hour to at least 1100° C.; and further heating to at least 1300° C., this temperature being maintained for at least one hour prior to cooling, is used as the solid electrolyte.