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. 11, 1976
Filed:
Apr. 19, 1971
Erhart K Drechsel, Houston, TX (US);
John B Sardisco, Shreveport, LA (US);
James R Stewart, Jr, Shreveport, LA (US);
Pennzoil Company, Shreveport, LA (US);
Abstract
Potassium phosphates useful as fertilizer materials, are produced by the reaction of phosphate rock or a solubilized form thereof, concentrated sulfuric acid and potassium hydrogen sulfate wherein the potassium hydrogen sulfate is added in a controlled manner and preferably in admixture with at least a portion of the sulfuric acid, the precipitated calcium sulfate precipitate is removed and the filtrate processed for recovery of the potassium phosphates. In further embodiments, high-sulfate containing filtrates are treated to lower the sulfate ion content of the products and effect partial neutralization by any of several methods such as by treatment thereof with fresh phosphate rock or source of calcium ion such as calcium oxide, alternatively or successively, and the resulting solution is used as a fertilizer, or liquids are removed and the solids are dried and/or dehydrated for recovery of the potassium phosphate compounds. Also methods are provided for the addition of nitrogen values.