The common granulation processes of compound fertilizer include high tower granulation process, drum granulation process and gunite granulation process.
High tower granulation process is mainly used for the production of high concentration nitro compound fertilizer. It can directly use concentrated ammonium nitrate solution, eliminating the links of slurry granulation, and granular compound fertilizer eliminates the process of crushing operation. The compound fertilizer granules produced by high tower granulation process are very uniform, with high qualified rate, good quality, easy to dissolve, and no caking occurs.
The slurry spraying granulation process uses slurry method. The slurry is sprayed into the equipment by heating and pumping. After the water in the slurry is vaporized and separated, the retained solid is formed into granular compound fertilizer. Its advantage is that it can be used to produce NPK compound fertilizer and ammonium phosphate compound fertilizer. At the same time, it has less energy consumption, large production scale, low production cost, and good quality and strength of products.
Rotary drum granulation process has little restriction on compound fertilizer formulation, high production yield, low investment and fast construction speed. It is favored by investors in small and medium-sized compound fertilizer plants and widely used in compound fertilizer production. The equipment investment of drum granulation process is small, and the compound fertilizer production line is simple. Equipment of rotary drum granulation production line mainly includes batching system, mixer, rotary drum granulator, drum dryer, rotary cooler, rotary screening machine, coating machine, packing machine. With the cooperation of these equipments, a complete set of compound fertilizers can be produced by fluidization, and the cost of producing compound fertilizers is low.
Rotary drum granulation process has unique advantages that other processes do not have, wide adaptability of raw materials, flexible production can produce a variety of concentrations, a variety of types (including organic fertilizer, inorganic fertilizer, etc.) of compound fertilizers.