Recent Developments in Granulation II
This material discusses developments in granulation techniques in the fertilizer industry, presented by Frank P. Achorn at the Seminar for Latin American Fertilizer Executives in September 1967. The number of granulation plants in the United States and abroad has been steadily increasing. Many companies that previously produced pulverized mixtures have converted their batch ammoniators to granulators to produce granular products. Large-scale granulation plants have incorporated pre-neutralizers to manufacture diammonium phosphate grades. The Tennessee Valley Authority (TVA) ammoniator-granulator has been widely utilized for the production of diammonium phosphate and triple superphosphate grades by major granular fertilizer producers. These products are often marketed through blending plants, where they are mixed with potash to create different nitrogen, P₂O₅, and K₂O ratios. The conversion of small pulverized-mix plants into granulation plants has involved modifying the batch mixers by installing ammonia and acid distributors. Sketches and flow diagrams illustrate these modifications and the operation of batch granulation plants. Rotary coolers are used to rapidly cool the granular products, with some producers choosing to screen and recirculate the cooled material to the granulator for improved quality control. Certain companies have further converted their ammoniators into continuous granulators by enlarging the discharge and operating continuously. However, due to production limitations, some companies plan to construct conventional ammoniator-granulation plants to achieve higher production rates.
Fertilizer industry, Ammonia