CO-CRYSTALLIZATION OF SMALL QUANTITIES OF SUBSTANCE WITH CRYSTALLINE PRECIPITATES

Co-crystallization of a microcomponent assumes a maximum magnitude in co- precipitation of radioelements with complex or binary salts, forming anomalous mixed crystals, when the macrocomponent in the precipitate and the microcomponent in the solution have an identical stoichiometric formula, regardless of the magnitudes of the ionic charge. The studies employ three groups of elements. Lanthanum oxalate and binary sulfates of lanthanum were used as carriers (the macrocomponents) and trivalent ponents. in one group the valence of the microcomponents was the same and in another differed from the carrier valence though their chemical properties were almost identical. In a third group the potassium salt K/sub 2/SO/sub 4/was the macrocomponent while trivalent Y/sup 91/, Ce/sup 141/, La/sup 140/, and Am/sup 241/ acte d as microcomponents. The experiments proved the feasibility of using isomorphous crystallization for determining the boundaries of formation of complex ions and instability constants of radioelements in solutions. (R.V.J.)