JPS6460692A - Dispersion stabilizer for coal-water slurry - Google Patents

Abstract

PURPOSE:To provide the title dispersion stabilizer which does not cause fluidity to be lost even when exposed to a high temp. under shearing, and which comprises a sulfonation product of poly-p-hydroxystyrene. CONSTITUTION:The title dispersion stabilizer comprises a sulfonation product of poly-p-hydroxystyrene (the MW of the poly-p-hydroxystyrene as a starting material is pref. in the range of 1,000-100,000; in the sulfonation product, the no. of sulfonic acid groups per phenol ring is pref. 0.3-1.0; and generally, the product is used in the form of a salt with Na, K, an alkanolamine, etc.). An aq. slurry of pulverized coal containing this dispersion stabilizer exhibits only a slight viscosity increase in high concns., has excellent fluidity, does not lose fluidity even when exposed to a high temp. under shearing, and maintains desirable dispersion stability without causing hard cake formation even when stored over a prolonged period of time. Accordingly, for the slurry containing the stabilizer, it is possible to perform pipeline transportation, tank storage and direct combustion in a boiler. Moreover, the aq. slurry of pulverized coal containing the dispersion stabilizer exhibits less bubble formation during production and less increase in slurry vol., so that the viscosity increase by air bubble can be avoided, thus ensuring desirable properties.