Abstract
Coprecipitation behavior of ruthenium in sea water with ferric hydroxide and cobalt sulfide was studied. It was found that the coprecipitation yield was considerably affected by chemical forms of ruthenium (chloro, nitrosyl nitrato and nitrosyl nitro complexes). With ferric hydroxide formed at pH 9 by adding sodium hydroxide or ammonia water, chloro complex was coprecipitated quantitatively, while nitrosyl nitrato and nitrosyl nitro complexes were coprecipitated as few as about 50 and 10%, respectively. When cobalt sulfide was formed at pH 9 by adding thioacetamide, all the three species were coprecipitated quantitatively. In the case of using ammonium sulfide as the reactant instead of thioacetamide, the coprecipitation yield for chloro complex was quantitative, but those for nitrosyl nitrato and nitro complexes were considerably reduced. The yields for the latter two species were increased with elapsed time after the addition of radioruthenium to sea water.
