process for oxydieren of aqueous thallium (i) or cerium (iii) - saline solutions to thallium (iii). cerium (iv) saline solutions by using electrolysis

摘要

1,209,991. Electrolytic oxidation. CINCINNATI MILLING MACHINE CO. Feb. 5, 1968 [Feb. 15, 1967], No.5620/68. Heading C7B. A solution of a thallium (I) or cerium (III) salt, e.g. the sulphate, is oxidized by passing the solution into the cathode compartment of a divided electrolyte cell, removing the cathodically generated hydrogen and passing the solution into the anode compartment of the cell in which oxidation of said metallic ion occurs to form the thallium (III) or cerium (IV) salt, removing the anodically generated oxygen and recovering the resultant oxidized metallic ion solution; the cell being divided by a membrane which whilst it impedes the back-migration of the oxydized metallic ion into the cathode compartment, permits transport of hydrogen ions through the membrane; and the electrode materials being essentially inert and such that the cathode has a sufficiently low hydrogen over-voltage to prevent reduction of the metallic ions, e.g. platinized platinum or platinized titanium, and such that the anode has a sufficiently high oxygen over-voltage to effect the oxydation of the metallic ions, e.g. lead, platinum, platinized platinum or platinized titanium. The electrodes may be supported between pairs of plastic grids. The membranes used may be of reinforced anion or cation exchange resin, microfibreglass matting or microporous membranes of polypropylene or P.T.F.E. Oxidation of the metal ions may result from an oxidizing agent formed at the anode-electrolyte interface, e.g. lead dioxide or activated oxygen. Cells may be assembled to operate in parallel, pumps and surge tanks being provided for passage of the electrolyte.