A CALCULATION METHOD FOR DETERMINING EQUILIBRIA IN METAL-AMMONIA-WATER SYSTEMS

Based on mass and charge balances, a simple and convenient calculation method is proposed, which gives equilibrium relations between a solid phase and the associated aqueous phase in terms of total concentratio ns rather than the activities of the dissolved species. This technique is illustrated with examples in the metal systems: Ni-, Cu- and Mg-am monia-water. For a given aqueous system, equilibrium diagrams, potenti al-pH diagrams, solubility curves and voltage-concentration ratio curv es can be calculated as a function of ammonia addition. This analysis has practical value in interpreting the process conditions required to conduct hydrometallurgical processes.