Extrusion granulation is a relatively new dry granulation process for producing compound fertilizers. Extrusion granulation was early applied to the granulation of potassium chloride in the fertilizer field. The granular (1-4mm) potassium chloride required for blending fertilizers (BB fertilizers) is basically produced by the extrusion method. In recent years, extrusion granulation for the production of compound fertilizers has developed rapidly in China.
The forms of extrusion granulation can be double-roller type and wheel rolling type. Double-roller extrusion first presses into large blocks and then crushes into granules. Such devices have large capacity, high particle strength and low energy consumption. Double-roller extrusion is widely used abroad. The wheel rolling type is to directly make hole groove shapes on the roller surface and extrude into formed particles at one time. The product strength is lower and sometimes binders need to be added. Suitable for making organic fertilizers and compound fertilizers and other granular fertilizers.
