Clays, both china and plastic, dominate the ultimate performance of the whiteware. industry. The rheology of clay-water systems/pastes is governed by the finer fractions or the colloidal particles. The evaluation of the clay fineness using Stoke's Law is time consuming for the whiteware manufacturer, especially in the small-scale sector in this country, who desires quick information which need not be very accurate. Clay minerals have the characteristics of absorbing certain ions and retaining them in an exchangeable state, i.e. these ions are exchangeable for other ions by treatment in an aqueous solution. Worrall developed a method using the above information. The method is inexpensive, quick and accurate enough for practical purposes. The method has been used to determine the specific surface areas of quite a number of clays used in this country in the whiteware Industry. To ascertain the efficacy of the method, clays douched with sulphuric and phosphoric acids were evaluated and results have been discussed. Â© 1983 Taylor & Francis Group, LLC.

K. N. Srinivasan

Papers

Rapid assessment of clay fineness by dye adsorption