The object of the study is a collective concentrate, which was obtained by flotation of sulfide lead-zinc ore from an East Siberian deposit using a combination of diesel fuel and butyl xanthate. In the collective concentrate the main ore minerals are galena and sphalerite. Non-metallic minerals are quartz, dolomite, calcite and chlorite. In the work were studied various methods of preparing a collective concentrate for a flotation selective cycle: without pulp preparation, washing with sodium sulfide, temperature, ultrasound, and bacterial treatment of a collective concentrate. The results of studies of the flotation selective cycle showed that it is impossible without preparation. Satisfactory technological indicators were not obtained when applying twice washing with sodium sulfide and using ultrasound. Introduction to the flow sheet of the operation of steaming in a medium of sodium sulfide and dosing of activated carbon into the process made it possible to obtain a foam product (lead concentrate) with a lead content of 45%, but the recovery was ~ 43%. In addition, the process is environmentally unfavorable, characterized by high material and energy costs. The prospects of using the bacterial method for preparing collective concentrates using diesel fuel for the flotation selective cycle are shown. The bacterial method consists in treating the collective concentrate with the bacteria Ochrobactrum anthropi and Pseudomonas aeruginosa JCM 5962.