Radiochemical investigation of coprecipitation of microquantities of some hydrolysable elements with hydroxides and oxides of metals

Coprecipitation of various amounts of Fe(3) (from 1 μg to 3.5 mg) with Sn(4), Ga, Th, Sc, Be, Cd and Mg hydroxides is studied as a function of pH. It is shown that coprecipitation of Fe(3) by the hydroxides of less acidic elements (Be, Cd, Ga and Sc) is preceeded by acidic-basic interaction with the macrocomponent ions. The interaction starts as the primary hydrolyzates of the macrocomponents appear in the solution. It becomes more intense as the difference in acidity between Fe(3) and the macrocomponent decreases. Iron (3) undergoes precipitation primarily in the form of a neutral hydroxocomplex Fe(OH)30. The effect of ions of Th, Sc and Be in the amounts equimolar with respect to the collector on the coprecipitation of iron (3) with tin (4) hydroxides has been studied. It is suggested that the observed increase in concentration of the microcomponent in the solution is due largely to the decrease in the hydrolytic precipitation of Sn(4) resulting from the interaction of the latter with the admixture ions