Powdered fertilizers are widely used in agriculture due to their ease of application and uniform nutrient distribution. Their production process revolves around “raw material purification → precise proportioning → fine shaping.”
Raw material pretreatment is fundamental. Raw materials are selected based on the type of fertilizer. Organic fertilizer raw materials require the use of composted livestock manure, straw, etc., which are dried or air-dried to adjust the moisture content to 10%-15% to prevent subsequent clumping; inorganic fertilizer raw materials such as urea and monoammonium phosphate require impurity removal to eliminate stones, impurities, and other foreign matter, while simultaneously reducing the water content through drying equipment.
Mixing and proportioning is the core process. According to the preset nutrient ratio, various pre-treated raw materials are fed into a fertilizer mixer. For example, the production of NPK compound fertilizer requires precise proportioning of urea, diammonium phosphate, potassium chloride, and other raw materials. During the mixing process, uniform mixing must be ensured to avoid excessively high or low local nutrient concentrations. Horizontal ribbon mixers or vertical disc mixers are typically used.
Crushing and screening are crucial for shaping. The mixed material needs to be crushed by a fertilizer crusher to ensure that the particle size meets the standard (generally requiring a pass rate of over 80 mesh). The crushed material then enters a screening machine, where different mesh sizes are used to separate unqualified particles. Coarse particles are returned for secondary crushing, while fine particles proceed to the next stage.
Inspection and packaging are the final guarantee. The screened powdered fertilizer is sampled and tested. Key indicators include nutrient content, moisture content, and particle size. After passing the inspection, the fertilizer is sent to the packaging stage, where it is quantitatively packaged by an automatic packing machine, sealed, and labeled with product information.
