PREPARATION OF ULTRA-HIGH-PURITY COPPER BY ANION-EXCHANGE

Equilibrium studies of anion-exchange distribution pointed out the fea sibility of eliminating virtually all the impurities from a copper chl oride solution containing copper initially in the monovalent state. El ution tests proved that the proposed anion-exchange separation can off er extremely high degrees of purification by utilizing both the mono-a nd divalent states of copper and by properly controlling the HCl conce ntration during the procedure. Initially, the Cu(I) chlorocomplexes ar e fixed and most of the impurities are eliminated, followed by an in s itu oxidation for eluting copper in the Cu(II) state while retaining t he rest of the elements in the column. Copper was extracted from the p urified and oxidized CuCl2-HCl solution by evaporation to dryness and hydrogen reduction. The produced copper sponge was melted in Ar-H-2 pl asma, followed by cold rolling, cutting, and wire drawing to obtain sa mples for glow discharge mass spectrometry (GDMS) analysis.