Edmund M Lapolla

US Patent:

40186814, Apr 19, 1977

Filed:

Nov 12, 1975

Appl. No.:

5/631370

Inventors:

Edmund M. LaPolla - Parsippany NJ
Charles F. Murphy - Morristown NJ
Arthur Sarkisian - Cranford NJ

Assignee:

International Telephone and Telegraph Corporation - New York NY

International Classification:

B01D 3700

US Classification:

210 66

Abstract:

Cellulosic solutions are filtered by a process enabling virtual complete recovery and recycling of the undissolved cellulosic components of the solutions. The process comprises filtering the solution through a bed of particulate material until the build-up of undissolved material impedes the further flow of solution through the bed, mixing the undissolved material and particulate bed with a solvent to partially dissolve the undissolved material, which is highly concentrated relative to its original concentration before filtration, adding a solubilizing reactant to said concentrated partial solution of undissolved material to complete the solution of the cellulosic residues, and separating and recycling the resulting solution.