Processes for Manufacturing Compound Fertilizers

In some chemical granulation processes, the solid raw materials, for example MOP, are partially dissolved in an ammonium phosphate and/or ammonium nitrate slurry and the mixture is then sprayed onto a bed or curtain of material in the granulator which is usually a heated rotary drum, for example, a Spherodizer . In this process, granules are formed primarily by accretion (refer to Chapter 13). 

0 mm in diameter, than do NPKs produced by other granulation processes. 

Feed Material Pressing Force Water Content Feed Particle Size 

This technology refers to the physical mixing (blending) of dry fertilizer materials without the deliberate introduction of chemical reactions or the enlargement of the material particle granule) size. The blending of solid and liquid fertilizer materials is also practiced in some instances to produce fluid multinutrient products. However, the production and marketing of fluid fertilizers are beyond the scope of this examination (refer to Chapter 10). 

Because of the importance that particle (granule) size plays in the preparation of high quality, homogeneous blends needed for balanced plant nutrition, many material suppliers provide the customer with very specific particle size data to help the blender closely match the various materials used to prepare a blended NPK product. The Size Guide Number (SGN) is one such type of particle size information wdely used in the industry. The SGN, developed in Canada, refers to the particle size of a material expressed in millimeters multiplied by 100, which divides a sample of material into two equal halves on a weight basis [6]. For example, if the mid-point or average particle size (weight basis) of a sample of material is 2.50 mm, the SGN would be expressed as 250. In this example, the blender would try to select all other 

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