Method for defluorinating wet process phosphoric acid
AssigneeIMC Fertilizer, Inc.
InventorsJoseph E. Gliksman, Dennis H. Michalski, Ronald L. Wiegel
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Abstract
A method for defluorinating wet process phosphoric acid. Phosphatic waste clay from phosphate rock beneficiation is mixed with the wet process phosphoric acid. The mixture is heated for a time sufficient to remove fluorine from the acid as gaseous silicon tetrafluoride. Phosphate is liberated from the phosphatic waste clay and thus is recovered in the defluorinated wet process phosphoric acid.
Claims19
A method for defluorinating phosphoric acid containing fluoride which comprises heating a mixture of said phosphoric acid and silica-containing phosphatic waste clay recovered from phosphate rock beneficiation at a temperature and for a time sufficient to reduce the fluoride concentration of the acid.
A method for defluorinating phosphoric acid having a P.sub.2 O.sub.5 concentration of at least about 30 wt. percent and containing fluoride, said method comprising heating under at least about 20 inches Hg vacuum a mixture of silica-containing phosphatic waste clay recovered from phosphate rock beneficiation and said phosphoric acid at a temperature between about 200.degree. F. and the boiling point of said mixture for a time sufficient to reduce the fluoride concentration of the acid.
Dependencies are inferred from the claim text.