Method of temporarily inhibiting the swellability of water swellable clays and compositions

Abstract

A method of temporarily inhibiting the swelling capacity of a water-swellable clay composition in contact with water includes mixing with a water-swellable clay a water soluble anionic polymer having a weight average molecular weight of about 2,000 to about 150,000 and water. The water soluble anionic polymers temporarily inhibit the swelling capacity of the water-swellable clays to decrease the viscosity of the clay slurry for transport, such as by pumping to a further treatment station such as a drier station. Also disclosed are the clay-water-anionic polymer compositions. The water soluble anionic polymers having a weight average molecular weight in the range of 2,000 to 150,000 temporarily will inhibit the swelling of a water-swellable clay so that the clay solids content of the slurry can be approximately doubled for treatment. The temporary swell-inhibiting properties of the relatively low molecular weight anionic polymers permit treatment and transportation of a clay slurry having a relatively low viscosity so that the clay solids content of the slurry can be substantially increased for primary treatment and then for transport to a secondary treatment station, such as a drier.

Dependencies are inferred from the claim text.