FIELD: electricity.
SUBSTANCE: method involves addition to the solution at temperature of 5 to 25 °C of hard ethanedioic acid or ethanedioic acid dihydrate, or its water solution, at molar ratio between copper cations and ethanedioic acid of 1.0:(0.8÷3.0) during 5-30 min. Solution is clarified during 5 min to 6 hours; the clarified portion of the solution is subject to filtration. Cupric oxalate settlings are removed mechanically or by dissolution in concentrated ammonia solution.
EFFECT: improving the removal of cations.
5 cl, 2 ex
