Silver powder was prepared by the liquid phase reduction method using silver nitrate as raw material, ascorbic acid as reducing agent and gum Arabic as dispersant. Using the Taguchi experimental design and the general linear model of variance analysis in Minitab software, the effects of reaction temperature, dropping time of silver nitrate solution, pH value on the tap density of silver powder were studied. The silver powder obtained under the optimal combination of parameters were pulverized by a jet mill, and their properties before and after jet pulvrization were compared. The experimental results showed that dropping time had a significant effect on the tap density of silver powder, and that the other two factors were non-dominant. The optimum parameters were as follows: 35℃ of reaction temperature, 90 min of dropping time and controlling pH=1. The density of prepared silver powder was 4.90 g/cm3 under the optimum conditions. The sample under optimum conditions were tested and analyzed after jet milling. It was found that the particle size distribution of the sample was reduced. The surface morphology was smoother and rounder than before pulverization. The XRD half-height width became larger due to the decreased grain size. The tap density increased to 5.42 g/cm3, indicating that jet mill can improve the quality of silver powder. |