Example of Revamping Phosphoric Acid Plants to Nissan C-Process

Phosphate fertilizer manufactures are suffering from demand decrease and low price. In order to survive in such circumstances, all are paying best efforts for the reduction of production cost and the simplest way for it is cutting down of raw material and utility consumption. In case of phosphoric acid production, main reduction methods of consumption are increase of P205 recovery from phosphate rock, saving of steam for concentration obtaining stronger acid from acidulation plant and use of this steam for co-generation and saving of electricity for rock grinding and agitation. Th increase of P205 recovery can be achieved by incorporating recrystallization step into rock decomposition procedure and the stronger acid can be separated from hemihydrate calcium sulphate. Nissan Chemical has various processes to comply with such requirements and here examples of revamping old phosphoric acid plant to more economical ones will be introduced.