羧甲基纤维素的应激反应规律及对滑石表面疏水性的影响

通过浮选实验、接触角测试、动电位测量及红外光谱试验研究不同的溶液条件对吸附在滑石表面的羧甲基纤维素(CMC)作用效果的影响,并考察其作用机理。结果表明,滑石具有较好的天然可浮性,CMC能够吸附在滑石表面,降低滑石的表面疏水性。吸附后的CMC对滑石的抑制作用效果受溶液pH及溶液中离子的浓度影响较大。当吸附有CMC的滑石位于pH=9的溶液中,CMC的羧甲基之间存在较强的静电排斥作用,吸附的CMC分子呈伸展状态存在,形成的吸附层较薄,造成的亲水性较弱；当矿浆pH变为酸性或溶液中有离子存在时,CMC羧甲基之间的静电排斥作用减弱,CMC分子在滑石表面呈蜷缩状态,所形成的吸附层较厚,造成的亲水性较强,这种变化是可逆的。

The stimulus response of CMC and its influence on talc hydrophobic

The influence of solution conditions on the depression effect of CMC that adsorbed on talc surface has been studied by flotation experiments, zeta potential measurements, contact angle tests and infrared spectra tests, and the mechanism was also discussed. The result showed that talc has good natural floatability. CMC can adsorb on talc surface and decrease talc surface hydrophobic. The depression effect of CMC is relation to pulp pH and ions concentration in the solution. When the talc that coated by CMC is located in solution of pH=9, there is a strong electrostatic repulsion between the carboxylic methyl of CMC, resulting in the CMC molecule exists in stretched state, the adsorbed layer is thin and the hydrophilic effect is weak. When the pulp pH changed to acidic condition or ions is present in the solution, electrostatic repulsion between carboxylic methyl of CMC is reduced, the CMC molecule existed in curled state and the surface adsorption layer is thicker. The change of talc surface hydrophobic/hydrophilic induced by CMC is reversible.