The stable basic sulfates of Co and Zn, as obtainable by NaOH at 20ยฐC, are respectively tetra-and tribasic. The mixed basic salts in equilibrium with mixed solutions of the sulfates show a considerable potential retention for Zn corresponding with a depletion of this element in the solution.
Up to 25 at. O h , Zn can be held in the hydroxyl sites of the tetrabasic Co structure with a partial bonding energy per atom 1000 times greater than in the pure tribasic salt of Zn.
With larger amounts of Zn, the basicity is lowered and with 40 at. Ya of Zn the tribasic lattice appears. In this, Co is preferentially held in the sulfate sites.
Le present travail est une contribution a I'etude des sulfates basiques de cobalt et de zinc.
Commencee par R. Lecocq [I] en vue de preciser les conditions de la separation de petites quantites de Zn dans des solutions riches en Co, cette etude fut cornpletee afin de mieux fixer la nature des sulfates basiques respectifs de Co et de Zn ainsi que le processus d'khange lie k la formation des sulfates basiques mixtes.