Patent ID: 6228212
Filing Date: 2001-05-08
Classification: D21C,Y02W

Abstract:
A method of removing wax from recycled cellulosic fiber, comprising the steps of:pulping the cellulosic fiber in a pulper to a suspension with a consistency of less than about 10% by weight;screening the suspension to remove contaminants;diluting the screened suspension to a consistency of less than about 3% by weight, said diluting step including diluting the suspension to a consistency of between about 0.2 and 2.0% by weight;removing wax from the diluted suspension using a froth flotation device, said wax removing step including the substeps of:controlling the pH of the suspension to between about 8.5 and 9.5;controlling an internal temperature of the froth flotation device to between about 85 and 160.degree. F.;introducing air into the suspension at a range of between about 40 and 200% air-to-stock ratio to generate foam which carries wax to the surface of the suspension; andremoving the foam with entrained wax therein from the froth flotation device; andadjusting the consistency of the suspension after said wax removing step.