胶体高岭土悬浮液的疏水聚团  

Hydrophobic Coagulation of Colloid Kaolinite Suspension

作　　者：胡阳[1] 刘令云[2] 宋少先[1] 闵凡飞[2] 

机构地区：[1]武汉理工大学资源与环境学院,湖北武汉430070 [2]安徽理工大学材料科学与工程学院,安徽淮南232001

出　　处：《非金属矿》2013年第3期7-9,共3页Non-Metallic Mines

基　　金：国家自然科学基金(51174006)

摘　　要：研究了pH值和十二烷胺(DDA)对高岭土悬浮液稳定性的影响,结果表明,当pH值小于5时高岭土颗粒开始凝聚,pH值大于5时高岭土颗粒处于分散状态,在靠近等电点处(pH值为3.2)凝聚度达到最高,为9.3%。当DDA加入溶液中后在pH值较高处高岭土絮凝也很强烈,并且凝聚度随DDA浓度上升而上升,当pH值为8、DDA浓度为1.1×10-3mol/L时凝聚度为43.45%,絮凝效果提升明显。利用扩展的DLVO理论计算了不同条件下高岭土颗粒间的势能变化,发现高岭土颗粒凝聚所需克服的能垒随pH值降低而降低。当吸附DDA后,疏水吸引作用势能的加入显著降低絮凝能垒,使得高岭土颗粒在高pH值时也能凝聚。同时DDA的吸附也降低了颗粒间的静电排斥势能。The effect ofpH value and dodecylamine （DDA） on the stability of kaolinite suspension was studied in this work, the results indicated that kaolinite particles aggregated at pH〈5 and dispersed at pH〉5, and the aggregation degree reached a peak value 9.3% at pH=3.2 which was close to lEE It was found that kaolinite particles coagulated strongly at the high pH value when DDA was added into the suspension and the aggregation degree increased with the increasing of DDA concentration, the aggregation reached 43.45% at pH=8, DDA concentration= 1.1 x 10.3 mol/L, suggesting the apparent developing of aggregation effect. The variation of potential energy between kaolinite particles under different conditions was calculated by extended DLVO theory, and it was found that the potential energy barrier which prevents the coagulation of kaolinite particles declined with the decreasing of pH value. After the adsorption of DDA on kaolinite particle surface, the flocculation energy barrier decreased significantly with the generation of hydrophobic attractive potential energy, resulting in the coagulation of kaolinite particles at the high pH value. At the same time, the adsorption of DDA also leaded to the decreasing of electronic repulsive potential energy between kaolinite particles.

关 键 词：高岭土 疏水化 十二烷胺凝聚度 

分 类 号：TD985[矿业工程—选矿]