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:
Sep. 12, 1978
Filed:
Mar. 18, 1977
Applicant:
Inventors:
John F McCullough, Florence, AL (US);
John F Phillips, Jr, Florence, AL (US);
Leslie R Tate, Florence, AL (US);
Assignee:
Tennessee Valley Authority, Muscle Shoals, AL (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C01B / ; C01B / ; C01F / ;
U.S. Cl.
CPC ...
423308 ; 423311 ; 423167 ; 71 33 ;
Abstract
A method of preparing dicalcium phosphate from phosphate rock wherein the rock is treated with a mixture of water, carbonyl, and sulfur dioxide. Solids are separated from the liquid phase. The solid phase consists of a mixture of gangue, and calcium .alpha.-hydroxysulfonate. Carbonyl and part of the sulfur dioxide are recovered from the solid by low temperature thermal decomposition. Dicalcium phosphate is precipitated from the liquid phase by partial distilling of SO.sub.2. All carbonyl is recovered for recycle.