Cleavage nature, electrokinetics, aggregation and dispersion of kaolinite
来源期刊:中国有色金属学报(英文版)2003年第6期
论文作者:胡岳华 孙伟 刘晓文 王淀佐
文章页码:1430 - 1434
Key words:kaolinite; cleavage planes; electrokinetics; self-aggregation; dispersion
Abstract: Quantum chemical simulation calculation shows that kaolinite is cleaved to produce (001) and (001-) basal planes. (001) plane is dominant by [SiO4] tetrahedral, which interacted easily with hydrogen ion or other positive ions by electrostatic forces or hydrogen bonding. (001-) plane is dominant by [AlO2(OH)4], which interacted easily with high negativity group such as -O-, -N-, F- etc. The apparent zeta potential and surface points of zero charge(PZC) are different for hard and soft kaolinites depending on their crystallinity index (HI). The self-aggregation between edge and basal plane due to the electrostatic interactions may occur at acidic media. The dispersion of kaolinite particles at alkaline media may be attributed to the electrostatic repulsion between basal planes and/or edges. The aggregation or dispersion behavior is revealed by scan electron microscope and the transmittance measurements for the suspension of kaolinite particles.