Piezoelectric Ceramic Waste Silver Recovery And Its Utilization

In this paper, silver was reclaimed from electron pottery scrap, then it was used toprepare AgNO₃, AgCN and silver nanometric powders. The influences of reactiontemperature, leaching time, dosage of nitric acid and the ratio of solid to liquid wereinvestigated. The results indicated that the optimum conditions were reaction temperatureof 85℃, leaching time of 90 min, the addition of 4.5 mL nitric acid and the ratio of 1 to3.5 of solid to liquid. The best dissolution rates of silver were 99.36%.The methods used for recovery silver have been compared. It indicated that useelectroanalysis method silver purity could reach to over 99.9%, and then Ag is used toprepare AgNO₃. According to national standard and testing method, the content of AgNO₃could reach to over 99.8%. The content of the impurities in AgNO₃ was close to sale ofA.R. As substitution of sale of A.R, it could be more economically.With the optimum preparation conditions of AgCN: reaction temperature 25℃, 1.05 oftheory NaCN dosage, stirring speed 200 r·min^-1, AgNO₃ concentration 0.50 mol·L^-1, NaCNconcentration 1.00 mol·L^-1, The production rate of AgCN could reach to over 92%.Liquid chemical reduction method was used to prepare evenly distributed and wellcrystallized spherical or sphere-like silver nanometric powders, deoxidized by hydrazineand surface protected by reagent PVP. Effects of reaction temperature, concentration, moleratio of reductant to AgNO₃ and surface protecting reagent on the mean particle size ofsilver nanometric powders were studied. With the optimum reaction condition: reactiontemperature 60℃, AgNO₃ concentration 0.05 mol·L^-1, reductant concentration 0.05mol·L^-1, mole ratio of reductant to AgNO₃5:1, weight ratio of AgNO₃ to PVP 1.5:1,spherical or sphere-like, mean particle size 25nm silver nanometric powders were received.