Additionally the slurry contains from 0.01% to 10% of a suspending agent such as bentonite clay, hydroxyethyl cellulose, methyl...http://www.google.es/patents/US4017324?utm_source=gb-gplus-sharePatente US4017324 - Clay slurries B???squeda avanzada de patentes N???mero de publicaci???nUS4017324 ATipo de publicaci???nConcesi???n N???mero de solicitudUS 05/443,560 Fecha de publicaci???n12 Abr 1977 Fe