A Modified Penetration Rate Method for Measuring the Wettability of Coal Powders

Abstract

Studies on the wettability of coal, or studies of interfacial phenomena, are essential to research and develop basically the coal utilizing technique.One of the authors, Murata, has been studying on the wettability of coal by the use of contact angle values measured by the liquid dropping method. But the surface of powder coal might be deteriorated in pressure-formation under this liquid dropping method. The wettability is necessary to be studied on powder coal itself.For that reason, authors have tried to measure the wettability of powder coal by penetration rate method, which was already used for pigment of glass bowl, or considered if this method was suitable and appropriate for research on the wettability of powder coal.As a result, it was confirmed that, among the three kinds of samples in this experiment, the wettabilities of coal were greatly different due to their differences in particle size distribution, but that, in each sample, an arbitary time was in linear relation to the squared penetration weight of liquid to that time. That is, this method proved to be appropriate for wettability measurement.