Abstract: Polysaccharides have been widely used as effective depressants of non-polar minerals,but studies on its mechanism and influencing factors are uncompleted.The progresses in this aspects are presented through summarizing studies on exploring the mechanism and influencing factors of employing dextrins,carboxymethyl cellulose(CMC),lignosulphonate and guar gum to depress talc and molybdenite.Also,analysis is made from the perspective of separating molybdenite from talc.The research shows that the depressing effect is influenced by the pH condition,ionic strength and ion types of the pulp and affected by the characteristics of polysaccharides molecular as well.As to the flotation separation from these two minerals,lignosulphonate could efficiently separate molybdenite from talc,and also the pre-adsorption of dodecane onto molybdenite could prevent the adsorption of lignosulphonate and make lignosulphonate as a efficient depressant.Besides,the depressing effect of polysaccharides should be not limited in the adsorption amount,also mainly depending on the character of adsorption.The adsorbing mechanism of lignosulphonate exists argument,including hydrophobic interaction,electrostatic interaction,chemical interaction,hydrogen bond,hydroxyl bond or their combination.

Key words: Lignosulphonate, Dextrin, CMC,Guar gum, Talc,Molybdenite, Depressant