Abstract: Molybdenite and talc are closely associated with each other and have similar floatability,so their efficient flotation separation is always a difficulty in flotation field. At present,the separation process of molybdenite and talc mainly includes positive flotation by floating molybdenite and reverse flotation by removing talc and then floating molybdenum. Both processes involve the inhibitor of molybdenite and talc and collector of molybdenite. In recent years,many new reagents for molybdenetalc separation have been reported,but there is a lack of systematic summary and analysis of the similarity,variability and difference of these reagents in terms of chemical composition,functional groups and steric configuration. Therefore,the research progress on the relationship between crystal structure and hydrophilic/ hydrophobic properties of molybdenite and talc is summarized. The types,adsorption mechanism and application effect of molybdenite and talc inhibitors are discussed in detail. The structure-activity relationship of inhibitors is analyzed,and the latest progress in molecular design of molybdenite/ talc inhibitors and molybdenite collectors is introduced. By summarizing the crystal structure and hydrophilic/ hydrophobic characteristics of the basal/ edge plane,it is found that the two minerals have strong hydrophilic properties due to ionic dissolution,oxidation and other behaviors on the edge planes. However,as the basal plane occupies more than 90% of the overall surface area,the two minerals show good natural hydrophobicity as a whole,which is the fundamental reason for the difficulty in flotation separation. Water-soluble metal salt is the traditional inorganic inhibitor of molybdenite and talc,but it has the disadvantages of large dosage and poor selectivity,so its application is limited. Organic polymers are the research focus of molybdenite/ talc inhibitors, which are often acidic in the pulp. The higher the alkalinity of the surface of molybdenite/ talc,the stronger the interaction between them. When the adsorption is "strong interactions",this acid-base interaction may appear as chemisorption;when the adsorption is "weak interaction",the effect is manifested as hydrophobic attraction,hydrogen bond attraction,electrostatic attraction and other forms of weak adsorption. Such inhibitors include polysaccharide,humic acid and so on. Therefore,based on the structure-activity relationship between the inhibitors and Mo/ Mg sites on the basal/ edge planes of the two minerals under the actions of functional group type and number,steric configuration and other factors,the design of highly selective molecular structures by combination or grafting synthesis is one of the ideas for the development of molybdenite/ talc inhibitors. The traditional collectors of molybdenite are mainly hydrocarbon oils and sulfhydryl compounds,but there are defects of poor dispersity and poor selectivity to molybdenite and sulfide gangue minerals respectively. Therefore,on the basis of hydrocarbon oil collector, from the perspective of the chemical interaction between collector molecules and the exposed sites on the edge planes,oxidation components and dissolved components,designing highly selective collectors containing N,P,S and other elements to achieve selective collecting of the fine-grained molybdenite with severe surface oxidation and dissolution is one of the development directions of molybdenite collector molecules. Inhibitors and molybdenite collectors are the keys to the separation of molybdenite and talc. It is of great significance to design green and efficient new reagents for the development of molybdenite.

Key words: flotation,molybdenite,talc,collector,depressant,structural-activity relationship