ABSTRACT

I. OVERVIEW OF POLLUTANTS AND CONTROL MAP (monoammonium phosphate) and DAP (diammonium phosphate) are produced from ammoniated slurry of wet-process phosphoric acid by granulation, drying, and cooling. NPK products are obtained by adding a potassium salt during the granulation. The production process is called slurry granulation. Various grades of NPK products are also manufactured by blending and granulation of powdery MAP, DAP, or superphosphates with nitrogen compounds such as urea and ammonium sulfate and potassium chloride or sulfate. The process is called powder blending granulation.