Investigation of tantalum (3,5) interaction with niobium (3,5) in sulfuric acid solutions by potentiometric method

Interaction of Ta(5), Ta(3) with Nb(5) and Nb(5), Nb(3) with Ta(5) in sulfuric acid solutions at cMtot=2x10-5-2x10-2 g-ion/l, cH2SO4=1-8 mol/l, t=70 deg C was studied by potentiometric method. It is ascertained that Ta(3) and Nb(5), Ta(5) and Nb(3) are indifferent to each other. No oxidation of tantalum(3) by niobium (5) and of niobium (3) by tantalum (5) takes place. In 1-6 mol/l H2SO4 interaction of Nb(5) with Ta(5) in the range of metal existence in polynuclear form was detected. Formation of heteronuclear complexes is accompanied by the destruction of Nb(5) and Ta(5) polyforms. The Nb(5):Ta(5) ratio in heteronuclear complexes at different cH2SO4 was calculated