The precipitation of some actinide element complex ions by using hexammine cobalt(III) cation — II: The precipitation of thorium, uranium(VI) and plutonium(IV), (VI) sulfate complex ions with hexammine cobalt(III) cation

Abstract

The precipitation behavior of thorium, uranium(VI), neptunium(V), plutonium(IV), (VI) and americium(III) in an ammonium sulfate solution with hexammine cobalt(III) ion was studied. Orange colored precipitates were produced in the case of thorium, uranium(VI) and plutonium(VI), and green yellow colored precipitate was produced in the case of plutonium(IV), respectively. On the other hand, no precipitate of neptunium(V) and americium(III) was observed under the same conditions. The compositions of the thorium, uranium(VI) and plutonium(IV) compounds were, respectively, di[hexammine cobalt(III)][thorium pentasulfate] dihydrate, [Co(NH 3) 6] 2 [Th(SO 4) 5]·2H 2O, di{[hexammine cobalt(III)]bisulfate} [uranium(VI) dioxo trisulfate] pentahydrate, {[Co(NH 3) 6]·HSO 4} 2 [UO 2(SO 4) 3]·5H 2O, and di[hexammine cobalt(III)][plutonium(IV) pentasulfate]trihydrate, [Co(NH 3) 6] 2 [Pu(SO 4) 5]3H 2O. Chemical and crystallographic properties of the three compounds and crystallographic property of the plutonium(VI) compound were also studied.