Abstract: In order to solve the problem of large fluctuation of sulfur concentrate index in Jinduicheng Molybdenum Industry Co., Ltd., Mining and Metallurgical Branch, the tests were carried out based on the on-site process flow, including the fineness of feeding grinding, the source of butyl xanthate, the timeliness of use after the preparation of liquid medicine and the concentration of liquid medicine. The results showed that the suitable grinding fineness of floating sulfur from molybdenum tailings is -200 mesh accounting for 55%. The source of butyl xanthate had no significant effect on sulfur selection. Butyl xanthate should be used immediately after it was ready. The suitable concentration of butyl xanthate is 6%. The correlation index could be obtained by carrying out sulfur selection practice according to the experimental conclusion.

Key words: grinding fineness, butyl xanthate, on-site preparing and using, concentration of liquid medicine