非极性表面矿物滑石与辉钼矿浮选分离中的多糖抑制

多糖作为非极性矿物表面抑制剂应用非常普遍,但关于其抑制机理和影响其抑制的因素研究还未完善。将国内外有关采用糊精、羧甲基纤维素(CMC)、木质素磺酸盐及古尔胶抑制滑石和辉钼矿的研究进行了总结,介绍了多糖抑制剂抑制非极性表面的研究进展,并从浮选分离滑石和辉钼矿的角度分析了这4种有机抑制剂对这2种矿物抑制的影响因素和抑制效果。研究表明,多糖的抑制效果不仅与矿浆的p H值、离子强度和离子种类有关,还与多糖分子的特性有关;在2种矿物的浮选分离方面,除了木质素磺酸盐能够高效率地分离滑石和辉钼矿外,十二烷在辉钼矿表面的吸附可有效阻止木质素磺酸盐的吸附,使木质素磺酸盐也可能成为滑石和辉钼矿有效分离的抑制剂;多糖对2种矿物的抑制不能仅从吸附量方面阐释,更重要的是多糖吸附层的特性;关于多糖的吸附机理则存在争议,主要有疏水力论、静电力论、化学力论、氢键和羟基作用论,或它们的综合作用论。

Depressing of Polysaccharides in Floating Separation of Talc from Molybdenite of Non-polar Surface Minerals

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.