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U.S. Department of Energy
Office of Scientific and Technical Information

Production of granular ammonium polyphosphate from wet-process phosphoric acid

Conference ·
OSTI ID:6676702

Although solid ammonium orthophosphates, such as MAP and DAP, are excellent fertilizer materials, the advantages of solid materials containing polyphosphate have been shown, particularly in connection with their use to make fluid fertilizers. The demonstration-scale pipe reactor/pug mill process at TVA has produced an excellent product; however, a suitable APP product also can be made with the pipe/drum granulator process, which is simpler, more economical, and readily adaptable to granulation plants in which pipe-cross reactors have been installed. This APP product is comparable to MAP for direct application and bulk blending, and it produces superior suspensions. The cost of production of APP should be no more than about 1% higher than that for MAP. APP also can be produced from sludge acid. So, it appears that production of APP containing 10% of the P/sub 2/O/sub 5/ as polyphosphate, instead of producing MAP, would be beneficial. TVA is in the process of modifying a TVA demonstration-scale plant to demonstrate the production of APP with the pipe reactor/drum granulator process. This 20-ton-per-hour unit is scheduled to start up in July 1985.

Research Organization:
National Fertilizer Development Center, Muscle Shoals, AL (USA)
OSTI ID:
6676702
Report Number(s):
TVA/PUB-84/42; CONF-8404174-3; ON: DE84901595
Country of Publication:
United States
Language:
English