Flotation of kaolinite and its interaction with hexadecylammonium bromide

The electrokinetic and flotation of kaolinite in solution of hexadecylammonium bromide were studied. The point of zero charge (PZC) of kaolinite was determined by measuring zeta potential (streaming potential method) as a function of pH. Hexadecylammonium bromide ion seems to be strongly adsorbed on the interface because it makes the zeta potential more positive as the concentration increases. The PZC of kaolinite is at pH 4.3. Floatability of kaolinite was studied and shown to be influenced by both collector and hydrogen ion concentration. The optimal flotation conditions (mainly pH value and concentrations) observed experimentally agree well with that of predicted from solution chemistry, and the floatability of kaolinite is poor if the pH value of flotation system is higher than 9 or lower than 2.