Dispersing Action of Condensed Phosphates on Barium Sulfate Suspension

Abstract

The dispersing action of condensed phosphates on barium sulfate suspension was examined. The deflocculating action of sodium pyrophosphate on barium sulfate particles decreases below pH 6.5 but long-chain polyphosphates show good deflocculating action between pH 3 and 8. In order to prove the hypothesis that the dispersing action of condensed phosphates is produced by the adsorption of the onion of condensed phosphate on the dispersed particles, amount adsorbed was measured in solutions of various pH. It was thereby found that the amount of adsorption decreased markedly in pyrophosphates, tripolyphosphates, and comparatively low-molecular polyphosphates with decrease in pH value, while changes in the adsorption with variation in pH were not so marked in long-chain polyphosphates.