Abstract: In a silver-lead-zinc ore of Russia，lead，zinc and silver content were 11.52%，28.76% and 187.00 g/t respectively.The lead accounted for 92.13% of the total，mainly in the form of lead sulfide；The zinc accounted for 92.35% of the total，mainly in the form of zinc.Zinc is difficult to recover by flotation process.The process of sulfuric acid leaching zinc was studied before lead flotation.Meanwhile the experiment in which a small amount of silver leached was recovered by thiourea has been carried out.The results showed that leaching rate of zinc，silver and lead were respectively 95.88%，35.51%，4.08% under the condition of the sulphuric acid concentration 180 g/L，liquid-solid ratio 5，at the temperature 85 ℃for the extraction time 60 min.If the dosage of thiourea is 1.2 times of the theoretical amount，reaction time is 30 min，the silver settling time is 6 h，in the acid solution ,the loss rate of zinc is 9.02% in theleaching process and the silver deposit rate is 87.23%.In the experiment，the separation of lead and zinc has been achieved，and the loss of zinc is small in the process of silver precipitation.

Key words: Lead zinc ore, Sulfuric acid leaching, Thiourea settling silver