THE EFFECT OF CONCENTRATION AND TEMPERATURE ON DIFFUSIVITY OF METAL-COMPOUNDS

The effect of concentration and temperature on diffusivity of various metal compounds which are frequently used in hydrometallurgical applications has been investigated. A diaphragm cell technique has been adopted in this study. Diffusivity of cobalt, nickel, copper, and iron compounds was measured in water with and without ammonia. The effect of chloride, nitrate, and sulfate on diffusivity of these metals in the above-mentioned solutions was studied. The effect of cyanide concentration on diffusivity of gold, silver, copper, and iron in solution was also investigated. The range of the concentration of solutions used in this study was 10-4 to 0.5 M. Temperature was varied between 15 °C and 45 °C. An empirical model for metal chloride, nitrate, and sulfate systems has been developed to predict diffusivity of various metal compounds when concentration, charge, size, and mobility of diffusing species are known. The predicted values of diffusivity of numerous metal compounds by this model are in good agreement with the observed values for the ionic strength less than 0.5 M. © 1990 The Minerals, Metals & Material Society.