Published December 1979
This report is concerned with the impact of ammonium phosphates on the worldwide fertilizer industry and processes for manufacturing ammonium phosphate fertilizers. The term ammonium phosphates designate a variety of fertilizers of either orthophosphates or polyphosphates or mixes of them. The two commercial forms of orthophosphates are monoammonium phosphate (MAP) and diammonium phosphate (DAP). Polyphosphate fertilizers contain a variety of polymeric forms mixed with some orthophosphate. Present production capacities for manufacturing ammonium phosphate fertilizers are given and future capacities are projected. The methods and economics of the principal modern manufacturing processes are evaluated and compared.
Basically there is only one commercial method for producing ammonium phosphates and that is by the reaction of ammonia with phosphoric acid. However, there are a number of variations in process techniques and objectives.
There have been significant improvements in commercial manufacturing a method in the last 10 years to complement the fast growth of the use of ammonium phosphates in worldwide agriculture.
In the process evaluations of this report, plant location is assumed to be near the principal U.S. phosphate source, Tampa, Florida. At this location, transportation charges can be ignored in the plant economics.
The stream efficiencies of fertilizer plants are normally lower than the average in the chemical industry, because of corrosion and problems in handling melts, slurries, and particles.
The stream efficiency factors used in this report vary from 0.84 to 0.90, depending upon the process, and are based on industry experience. The report was prepared with the aid of the information in pa- tents, technical articles, trade journal articles, books, and material supplied by process licensers and engineering-construction companies.
