A new process was proposed for extracting cadmium from cadmium-containing raw materials by the ammonium-ammonia method.Investigation on leaching in the process for treating an electric precipitation dust from ISP sintering factory was carried out.The best conditions were established as follows:the ratio of liquid to solid was 2.5

［NH3］/［NH4+］=3/5

total concentration of ammonium and ammonia was 8 mol8226;L-1

the leaching time was 1.5 h at 35℃.Under the above conditions

leaching rate of cadmium and its concentration in the leached solution was 90.99% and 8.74 g8226;L-1

respectively.