Separation of valent forms of chromium (3) and chromium (6) by coprecipitation with iron (3) hydroxide

Soption 9.62x10-5 mol/l of 51Cr radioactive isotope in oxidation states 3 and 6 by iron(3) hydroxide in 1 mol/l of KNO3 and KCl depending on pH medium is investigated. The region of practically total concentration of Cr(3) and Cr(6+) (pH=3-6.5) is determined. The results of spectrophotometric investigations, calculational data on distribution of hydroxocation forms of chromium (3) and of chromium (6) anions and sorption by iron (3) hydroxide permit to characterize sorption of chromium forms in different stages of oxidation. The methods of chromium (3) and chromium (6) separation by coprecipitation of iron (3) hydroxide and their precipitation from it is developed on the above foundation