Quantitative Fabric of Wet Kaolinite

Abstract

A method is described for quantitatively expressing orientation of kaolinite particles in a wet clay mass. Wet clay is impregnated with a polyalcohol which permits grinding of a very flat surface (without disrupting the original fabric) for quantitative X-ray measurement. In the specific procedure discussed, a Norelco diffractometer equipped with a pole figure device and a Geiger detector was employed to measure by reflection the diffracted intensity of the 002 and 020 kaolinite reflections. The amplitude of the 002 peak to the amplitude of the 020 peak is called the peak ratio, PK, which quantitatively expresses particle orientation at any chosen angle to the specimen surface. Limits of orientation are random and maximum orientation. For the kaolinite tested, truly random orientation was achieved which gave a PR = 2.0. Maximum orientation found experimentally was PR = 200 for thoroughly dispersed slurry slowly dried on a glass slide. Vertical and lateral variations can be measured either continuously or in steps of any chosen size.