( 中南大学 资源加工与生物工程学院， 长沙 410083)
摘 要: 采用季铵盐DTAL作捕收剂，研究了氯化钠对一水硬铝石和叶蜡石浮选的影响及其作用机理。随着氯化钠浓度的增加，叶蜡石的浮选回收率显著提高，而一水硬铝石的可浮性受其影响很小。机理研究表明：氯化钠对一水硬铝石的zeta-电位没有影响，而能显著降低叶蜡石的zeta-电位，增强捕收剂与叶腊石的静电作用，促进捕收剂的吸附而活化其浮选；叶蜡石表面电位的降低是因为氯离子对叶蜡石存在选择性吸附作用并对其结构进行插层，使得叶蜡石的层间距从0.93 nm增大至1.40 nm。溶液化学计算表明：氯化钠改变溶液的离子强度，显著降低了季铵盐阳离子表面活性剂的临界胶束浓度，使得吸附了捕收剂的矿物表面更容易疏水上浮。
关键字: 氯化钠； 插层作用； 特性吸附； 临界胶束浓度； 浮选
（ School of Resource Processing and Bio-engineering,
Central South University, Changsha 410083, China）
Abstract: The effects and mechanisms of sodium chloride on the flotation of diaspore and pyrophyllite with the cationic quaternary ammonium DTAL as a collector were studied. The presence of sodium chloride was determined to activate the flotation of pyrophyllite, leaving diaspore flotation unaffected. Zeta potential measurements corresponded to the flotation tests. It is indicated that sodium chloride decreases marked by the zeta potential of pyrophyllite, leaving the zeta potential of diaspore unaffected. The decline of zeta potential can increase the electrostatic interaction between collectors and pyrophyllite, accordingly prompting the adsorption of the collector and activated the flotation of pyrophyllite. Chloride ion can be selectively adsorbed on the pyrophyllite and the intercalation in the layers of pyrophyllite which resulted in the swell of the d space from 0.93 nm to 1.40 nm. Solution chemistry demonstrates that electrolytical ion would decrease the critical micelle concentration and increase the hydrophobility of the collector, which have benefits on the separation of diaspore and pyrophyllite.
Key words: sodium chloride; special adsorption; intercalation; critical micelle concentration; flotation
