All phosphate ores contain levels of fluorine which are toxic to animals.
Defluorination is required in the production of feed phosphates and is essential for the health of the animals to which they are fed. The feed phosphate produced by several different companies in the Florida phosphate industry include calcium phosphates, defluorinated phosphates, ammonium phosphates and defluorinated phosphoric acid. Concentrated wet-process phosphoric acid from which the fluorine has been removed is used in the manufacture of the calcium phosphates, ammonium phosphates and defluorinated phosphoric acid. The calcium phosphates are produced from the defluorinated phosphoric acid and high grade limestone while the ammonium phosphates are produced from the same quality acid and anhydrous ammonia.