CHARACTERIZATIONS AND STABILITY OF COLLOIDAL COAL-MEASURE KAOLINITE IN AQUEOUS SUSPENSIONS: A REVIEW

Coal-measure kaolinite is a main gangue mineral in coal deposits. Because of the colloidal particle size, the kaolinite is very stable in coal tailing slurries, leading to a high turbidity of recycled water in coal washing plants. The coagulation of colloidal kaolinite in aqueous suspensions is an essential problem in many coal washing plants. This review highlights the characterizations and stability of colloidal coal-measure kaolinite in aqueous suspensions. The characterizations include mineralogy, electrokinetics and hydration layers on kaolinite surfaces. The coagulation of colloidal kaolinite in aqueous suspensions is reviewed and discussed on the basis of the DLVO theory and the characterization. In addition,the main parameters of affecting the coagulation, such as suspension pH, electrolytic ions and temperature, are summarized.