Phosphate rock is reacted with phosphoric acid to produce monobasic calcium phosphate. Monobasic calcium phosphate is reacted with ammonium carbonate to produce ammonium phosphate. Dibasic calcium phosphate is also produced as a by-product when monobasic calcium phosphate reacting with ammonium carbonate. The dibasic calcium phosphate is reacted with sulfuric acid to produce phosphoric acid. The phosphoric acid is used to react with phosphate rock. Ammonium sulfate or ammonium hydroxide may be used instead of ammonium carbonate. Phosphate other than ammonium phosphate can be produced if calcium phosphate is reacted with x-y to produce x-phosphate, where x is lithium, sodium, ammonium or potassium and y is carbonate, bicarbonate hydroxide or sulfate.