COPRECIPITATION OF TRANSURANIUM ELEMENTS FROM ALKALINE-SOLUTIONS BY THE METHOD OF APPEARING AGENTS - I - COPRECIPITATION OF PU(VI,V) WITH MANGANESE-DIOXIDE

Compounds difficultly soluble in alkalis and promising as carriers for coprecipitation of transuranium elements from alkaline solutions are selected. These include MnO2, Mn(II), Fe(III), Co(III), Co(II), and Cr (III) hydroxides and sodium uranates. The optimal conditions of precip itation of manganese dioxide through reduction of MnO4- are defined. T he behavior of Pw(VI) in manganese dioxide precipitation is studied ov er the alkalinity range from pH 9.5 to 7 M OH-. It is found that pluto nium is efficiently coprecipitated in the presence of H2O2 or SO32- in solutions with [OH-] less than or equal to 1 M.