Morris A Clark

US Patent:

41016360, Jul 18, 1978

Filed:

Jan 21, 1977

Appl. No.:

5/761049

Inventors:

Harold V. Larson - Pasadena TX
Morris E. Clark - Pasadena TX

Assignee:

Olin Corporation - New Haven CT

International Classification:

C01B 1516
C01B 2526
C05B 1300

US Classification:

423305

Abstract:

An improved process is described for preparing defluorinated phosphate rock from fluorine-containing phosphate rock which contains acid insoluble impurities in excess of about 6 percent by weight. The improvement is particularly useful in the fluidized bed technique for preparing defluorinated phosphate rock wherein fluorine-containing phosphate rock, a sodium compound such as sodium carbonate, phosphoric acid and water are admixed to form granules. The resulting granules are dried and heated in a fluidized bed calciner at a temperature within the range of from about 980. degree. to about 1,350. degree. C to evolve sufficient fluorine to produce defluorinated phosphate rock graules having less than 1 part of fluorine per 100 parts of phosphorus by weight. The resulting defluorinated granules are colled and stored for use as an animal feed which contains at least 18 percent by weight of phosphorus. The improvement of this invention comprises admixing a lime compound with the phosphoric acid, prior to mixing with the other ingredients, to form a lime-acid slurry having a CaO to P. sub. 2 O. sub.