Research On The Flotation Separation Of Rich Silver Lead-zinc Ore

Lead and zinc are both the mineral resources with dominant position, meanwhile, we are the biggest manufacturing and consuming country of lead and zinc. The most important property of the lead and zinc resources is the high content of associated silver. At present,70%～80%of the silver output are coming from lead and zinc deposits, but the recovery of silver from the lead and zinc flotation is low, with about58%～75%. So, the further research on the flotation of lead and zinc with rich silver content is of great contribution to the enhancement of recovery of associated silver.One sulfide lead and zinc from Yunnan province, contained3.69%lead,4.77%zinc and93.81g/t silver, greater than the associated silver content of2g/t standard, which is the typical lead-zinc mine with rich silver.Raw ore silver value share of more than a third,the properties of the ore determained the necessary of recovering silver.The result of process mineralogy showed that the lead dstributed in the galena and boulangerite is90.87%, the zinc dstributed in the blende is and boulangerite is98.01%, the silver distributed in the galena is70.21%, in the freibergite, boulangerite etal independent silver mineral is15.33%, so increase the recovery of the galena and the independent silver mineral is the key process.The technological process of differential flotation of lead and activation prior to zinc flotation was adopted. In the lead flotation, sodium carbonate and zinc sulfate were combined as the depressant, HA (Ammonium butyl aerofloat is the main ingredients) as the collector, so as to enhance the recovery of galena,freibergite and freieslebenite. In the zinc flotation, copper sulfate was used as the activator and butyl xanthate as the collector. At last, lead concentrate with grade and recovery of lead as58.01%and87.12%, silver grade and recovery as1401.09g/t and82.20%, zinc concentrate with grade and recovery of zinc as54.70%and91.65%, silver grade and recovery as66.19g/t and5.50%were obtained. The beneficiation process structure and the reagent system of this test could provid reference to the other similar lead and zinc mines.Results of the flotation of single mineral showed that the combined depressant of sodium carbonate and zinc sulfate had strong inhibiting ability on the sphalerite but weak for the galena. The flotability of sphalerite dropped rapidly with the increase of pH, especially for the pH adjusted by the lime and sodium carbonate. No obvious influence of Fe3+, Pb2+and Cu2+on the recovery of galena was found. While for the flotation of sphalerite, Fe3+had somewhat activation, Pb2+had strong activation and Cu2+within the appropriate dosage showed activation. That is when the concentration of Cu2+surpassed the appropriated value, it restrained the flotation of sphalerite other than activated it.