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AssigneeAgrico Chemical Company
InventorsKenneth L. Parks, Kyle D. Clevenger, Daniel P. McDonald
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Magnesium and aluminum impurities may be removed from wet process phosphoric acid by adding a fluoride ion donating compound, such as hydrofluoric acid, for example, to thereby provide about four fluoride ions for each aluminum ion. Also, preferably, an aluminum ion donating compound, such as alum is added to the wet process acid to bring the aluminum ion to magnesium ion ratio up to about two to one to facilitate formation of crystalline compounds having the general stoichiometry MgAl.sub.2 F.sub.8. The treated filter grade acid is then further treated in a crystallizer to form large crystals which will readily precipitate so the purified liquid phase, low in magnesium and aluminum containing impurities, may be separated from the crystalline phase.
A method for removing magnesium and aluminum impurities from wet process phosphoric acid without subjecting said acid to treatment for silicon removal, consisting essentially of:
A method of removing magnesium and aluminum impurities from wet process phosphoric acid without subjecting said acid to treatment for silicon removal, which method comprises:
A method of removing magnesium and aluminum impurities from wet process phosphoric acid without subjecting said acid to treatment for silicon removal, which method consists essentially of:
Dependencies are inferred from the claim text.