The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 18, 1993
Filed:
Oct. 15, 1991
Applicant:
Inventors:
Paul A Rey, Coraopolis, PA (US);
Wood E Hunter, Pittsburgh, PA (US);
Assignee:
Calgon Corporation, Pittsburgh, PA (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
C01B / ;
U.S. Cl.
CPC ...
4233 / ; 423320 ;
Abstract
A method for improving gypsum slurry filtration in the production of wet process phosphoric acid wherein an effective amount of carboxylic-type polymer having a portion of sulfonic functionality is used as the filtration aid. Preferred polymers are high molecular weight polymers of acrylic acid and acrylamido methylpropyl sulfonic acid.