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. 09, 1989
Filed:
Jul. 28, 1987
Gary D Derdall, Saskatoon, CA;
William R Erickson, Lakeland, FL (US);
Robin L Phinney, Saskatoon, CA;
James D Wilson, Lakeland, FL (US);
Potash Corporation of Saskatchewan, Saskatoon, CA;
Abstract
A process and apparatus for producing phosphoric acid by the recovery of P.sub.2 O.sub.5 from a phosphate ore is disclosed. A slurry of a phosphate ore in an aqueous phosphoric acid solution is formed in each of a plurality of reaction zones connected in series. Phosphate ore is introduced into the first reaction zone and phosphoric acid into the last reaction zone whereby the reaction of the phosphoric acid with the ore forms a slurry of coarse solids, fine solids and monocalcium phosphate in the phosphoric acid solution. A first process stream comprising coarse solids is removed from the first reaction zone and each of the other reaction zones and is transferred to the adjacent, successive reaction zone. A second process stream comprising fine solids is removed from the last reaction zone and the other reaction zones and is transferred into the adjacent, preceding zone in a direction which is countercurrent to the direction of flow of the first process stream and is concurrent with the direction of flow of the phosphoric acid from the last to the first reaction zones. A differential of phosphoric acid concentration is maintained between the reaction zones with the concentration decreasing in each reaction zone in the direction of flow of the first process stream.