Abstract: A high-carbon lead-zinc ore in Ganluo,Sichuan,contains Pb of 2.45% and Zn of 4.65%,with an oxidation rate ranging from 10% to 30%,belonging to mixed lead-zinc ore.The ore has a high organic carbon content,which tends to cause non-selective adsorption of flotation reagents,resulting in high reagent consumption and severe Pb-Zn mutual content in the existing flotation process.To improve the separation performance,a decarburization stage was introduced prior to lead flota tion,using a mixture of kerosene and diesel (mass ratio 1∶1) as the decarburization collector,followed by optimization of the reagent regime through conditional tests.Based on the original closed-circuit flotation process of "one roughing,four cleaning, four scavenging with middlings return" for lead and "one roughing,four cleaning,five scavenging with middlings return" for zinc,the decarburization stage significantly reduced the mutual content of lead and zinc in the concentrates.The lead concen trate with a Pb grade of 51.22% and Pb recovery of 88.85%,and the zinc concentrate with a Zn grade of 51.17% and Zn re covery of 71.22% were obtained.Compared with the process without decarburization,the mutual content of lead and zinc in the concentrates was significantly reduced,and the separation indexes were notably improved.

Key words: flotation,high carbon,lead-zinc ore,decarburization,process optimization