Process for manufacturing ammonium phosphate utilizing an oxalic acid acidulating process

摘要

A process for the manufacture of phosphoric acid from phosphate rock is provided. The phosphate rock is digested or acidulated with an acid solution containing oxalic acid to produce phosphoric acid and calcium oxalate. Useful by-products are also formed and include calcium carbonate and ammonium oxalate. More specifically, the process provides for the production of phosphoric acid, ammonium phosphate and useful by-products utilizing synthesis gas and air to produce oxalic acid and ammonia. The synthesized oxalic acid is utilized for phosphate rock digestion to produce phosphoric acid, which can be reacted with ammonia to produce ammonium phosphate. Calcium oxalate from phosphate rock digestion is utilized to produce calcium carbonate, ammonium oxalate and oxamide.