John A Roy

US Patent:

44230150, Dec 27, 1983

Filed:

Feb 4, 1982

Appl. No.:

6/345949

Inventors:

John W. Roy - Gainesville FL
Melvin J. Arbie - Live Oak FL
Joel P. Holmes - Lake City FL

Assignee:

Occidental Chemical Company - Los Angeles CA

International Classification:

C01F 100
C01F 500
C01F 1100

US Classification:

423167

Abstract:

In a process for producing a defluorinated product containing calcium, sodium and phosphorus, by calcination of a mixture of phosphate rock, with caustic soda, phosphoric acid and water, an improvement comprises maintaining the amount of phosphoric acid in the mixture such that the ratio of phosphorus in percentage by weight on a dry basis in said mixture-to-the phosphorus desired in percentage by weight in the calcined product is substantially equivalent to the ratio of the calcium in percentage by weight on a dry basis in the mixture-to-the calcium in percentage by weight in the calcined product. The process is especially useful where the phosphate rock has a bone phosphate of lime analysis of about 73% or less (e. g. , about 71. 5%), and also where the caustic soda is added to a mixture of phosphate rock and phosphoric acid prior to the addition of water.