REMOVING METHOD FOR IRON IN THIOCYANOGEN TYPE QUATERNARY AMMONIUM SALT EXTRACTING SOLVENT

摘要

PURPOSE:To regenerate an iron-contg. thiocyanogen type extracting reagent by contacting the reagent to an aq. soln. contg. an alkylenepolyamine acetate type chelating agent to shift the iron into the soln. and separation-remove it. CONSTITUTION:Medium and heavy rare earth elements are separated from an aq. soln. contg. Y and the elements with a thiocyanogen type quat. ammonium salt extracting soln. Fe contained in the aq. soln. is also shifted into the extracting soln. and accumulated. In order to separation-remove the iron from the extracting soln. contg. the medium and heavy rare earth elements, the soln. is adjusted to pH>=5 and contacted to an aq. soln. of an alkylenepolyamine acetate type chelating agent such as ethylenediaminetetraacetic acid, whereby the Fe is shifted into the chelating agent soln. and separation-removed. The Fe-free thiocyanogen type extracting soln. is recycled.