A novel approach for flotation separation of talc and molybdenite: Scrap steel-molybdenite galvanic corrosion treatment and its mechanism

Molybdenum is an important strategic resource. Talc-type molybdenite is abundant in reserves, but it is difficult to separate talc and molybdenite efficiently and cleanly because of their similar strong hydrophobicity. In this paper, the effect of galvanic corrosion between scrap steel and molybdenite on flotation behavior of molybdenite was studied under different conditions (different scrap steel materials, slurry water content, galvanic corrosion time and galvanic corrosion ambient temperature).The method for flotation separation of molybdenite and talc by galvanic corrosion of scrap steel-molybdenite was established for the first time. In addition, XPS, SEM, TOFSIMS, contact Angle test and electrochemical test were used to study the effect of galvanic corrosion of scrap steel-molybdenite on the surface properties of molybdenite and talc. The results show that strong galvanic corrosion between scrap steel and molybdenite can significantly reduce the hydrophobicity of molybdenite, but there is no galvanic corrosion between scrap steel and talc under the same conditions, and scrap steel has no significant effect on the surface hydrophobicity of talc. Therefore, the galvanic corrosion of scrap steelmolybdenite can effectively expand the floatability difference between talc and molybdenite, and strengthen the flotation separation of molybdenite and talc. The flotation test results of artificial mixed ore show that in the case of mineral mixing, the galvanic corrosion of scrap steel-molybdenite still shows a strong inhibition effect on molybdenite flotation, so that 97.04 % of molybdenite in the mixed ore is inhibited into the tailings (molybdenite products). The research results expand the new high-value utilization way of scrap steel in sulfide ore flotation, and help to promote the sustainable development of iron and steel industry and sulfide ores industry. In addition, the research results also have reference significance for the use of scrap steel galvanic corrosion to inhibit other sulfide ores such as pyrite and arsenopyrite.