Obtaining highly dispersed powders from electrolytes with additives

Abstract

1. An investigation was made into the effect of the silver nitrate concentration and cathode current density on the structure, properties, dispersity, and homogeneity of silver powders obtained by electrolysis from silver nitrate solutions. 2. It was shown that the dispersity of the powder may be increased considerably by reducing the silver nitrate concentration. But this method cannot be used in practice, because the silver concentration in the solution increases during electrolysis. 3. It was established that an increase in the cathode current density leads to a decrease in grain size and darkening of the precipitate. 4. The effect of surface-active and luster-forming additives on the structure and properties of silver powder was investigated. 5. It was shown that addition of organic substances to the electrolyte may increase considerably the dispersity and uniformity of the powder. 6. Electrolytes with admixtures of Novost', OP-7, and dextrin are proposed for obtaining highly dispersed, light-colored, homogeneous silver powders. An electrolyte with an admixture of Novost' (0.5 g/liter) has been employed for industrial production of highly dispersed silver powder.