Synopsis.

Some aspects of the design and operation of two SAI compound fertilizer granulation plants are reviewed - firstly the modified SAI-R Granulation Plant at Leith producing ammonium nitrate based fertilizers and secondly the recently constructed Solid Feed Granulation Plant at Aberdeen manufacturing fertilizers based on ammonium phosphate intermediates. In the original SAI-R Granulation process phosphoric acid, nitric acid and ammonia together with potash were fed to SAI-R granulators and the plant at Leith operated in this manner for several years. It became necessary, however, to increase the output from this plant and the acid and ammonia feeds to the granulators have been replaced by low moisture ammonium phosphate/nitrate liquor. The Aberdeen Granulation Plant is required to produce a wide range of slightly lower analysis formulations including horticultural fertilizers and the design is based on the use of solid raw materials and fertilizer intermediates.

The paper concludes with a review of certain aspects of fertilizer plant design, safety, operation and maintenance.

G B Whyte, C.Eng, MIMechE., Scottish Agricultural Industries Ltd, Edinburgh, UK.

50 pages, 11 figures, 17 references.