METHOD FOR MANUFACTURING AN AMMONIUM PHOSPHATE FERTILIZER HAVING LOW CADMIUM CONTENT

The invention relates to a method for manufacturing an ammonium phosphate fertilizer from a phosphoric acid aqueous solution that has less than 50% P205 concentration and is obtained by wet inorganic phosphate treatment, said phosphoric acid containing traces of cadmium. Said method includes the following steps: (a) neutralizing said phosphoric acid solution (1) with ammonia (3) up to a molar ratio N/P of between 0.1 and 0.8; (b) reacting said partially neutralized solution (4) with a sulfide source (6) so as to form a cadmium sulfide precipitate (9); (c) separating said precipitate (9) so as to obtain a refined ammoniated phosphoric acid solution (10), and (d) ammoniating and granulating said refined solution (10) so as to form said fertilizer (12).