Electrokinetic potentials of mineral oxides and calcium carbonate in artificial seawater

Electroacoustic method was used to measure the ζ potentials of mineral oxides and calcium carbonate in artificial sea water (pH 8), and the following values were obtained: synthetic hematite: 0.87 mV; goethite: 1.01 mV; fumed silica: -3.56 mV; quartz: -1.38 mV; calcium carbonate: 1.91 mV. The absolute values of the ζ potentials obtained in the present study are substantially lower than the ζ potentials in seawater reported by other authors. Our results indicate that the effect of electrostatic repulsion in the interactions between the particles of these materials in seawater is negligible. © 2002 Elsevier Science Ltd. All rights reserved.