Thermodynamic Analysis on Preparing the Precursor of Fibre Ag Powders with the Oxalate Precipitation Process

According to the principles of simultaneous equilibrium and mass balance,a series of thermodynamic equilibrium equations of Ag(Ⅰ)-C2O42——NH3-NH4+-H2O system at ambient temperature were deduced theoretically and the logarithm concentration verus pH value(lgT-pH) diagrams at different solution compositions were drawn.The results show that when pH is above 5.0 or below,the morphology of silver precursor powders may change with pH.Some experiments were done to confirm the model is correct and the calculated values are basically accurate.