高岭石对金属阳离子的吸附特性研究

Adsorption characteristics of metal ions on kaolinite

煤泥水中高岭石颗粒表面荷负电是其难以沉降的主要原因。通过高岭石对Ca^(2+)、Mg^(2+)、K^+、Na^+四种离子,分别进行了单离子吸附试验、双离子的竞争吸附试验和四离子的竞争吸附试验,使用离子色谱仪测定在不同的吸附条件下各金属阳离子的浓度,并计算其吸附量。结果表明:高岭石对金属阳离子的吸附量随着吸附时间的增加而增加,约90 min后趋于平衡;高岭石对单种金属阳离子的吸附量大小顺序为:Ca^(2+)>Mg^(2+)>K^+>Na^+,在双离子和四离子竞争吸附中,其吸附竞争能力也满足该规律。本研究将为水质调控的煤泥水絮凝沉降处理技术提供理论基础。

The adsorption of negative charge on kaolinite particles surface is the main reason that causes coal slime water settle difficult. By studing adsorption dynamics of Ca^(2+),Mg^(2+),K^+and Na^+on kaolinite,adsorption tests of single kind of ions on kaolinite,competitive adsorption in two kinds of ions and four kinds of ions were carried out. The concentrations of metal ions in different conditions were measured using ion chromatography,and then adsorption amount of metal ions on kaolinite were calculated. The result shows that the adsorption amount of metal ions on kaolinite is increasing until the adsorption reached equilibrium after 90 minutes,the order of adsorption amount of single kind of metal ions on kaolinite is Ca^(2+)> Mg^(2+)> K^+> Na^+,and the competitive adsorption in two kinds of ions and four kinds of ions also agree with this rule. This study will provide a theoretical basis for water chemistry regulation technology of coal slime water flocculation and sedimentation treatment technology.