Compound fertilizer is a staple in agricultural production, characterized by comprehensive nutrients, stable efficacy, and broad applicability.Standardized compound fertilizer production lines leverage mechanized and automated processes to achieve large-scale, high-quality production. The entire workflow features seamless integration and rigorous multi-stage quality control, ensuring uniform nutrient distribution and consistent granule uniformity; the specific production process comprises eight core stages.

The first step is raw material pretreatment and precise proportioning. The process primarily utilizes basic N-P-K raw materials such as urea, monoammonium phosphate (MAP), and potassium chloride. Clumped materials are first crushed to a standard fineness to prevent uneven granules from affecting subsequent processing. Next, an automated batching system precisely weighs the ingredients according to specific formulas, strictly controlling nutrient ratios to ensure the product meets standards at the source and suits the growth needs of various crops.
The second step is the mixing process. The proportioned materials are fed into a double-shaft paddle mixer for thorough blending, ensuring that nitrogen, phosphorus, potassium, and secondary/micro-nutrients are evenly distributed and eliminating localized nutrient imbalances. Uniform mixing is crucial for balanced fertilizer efficacy, effectively preventing issues such as uneven nutrient distribution or inconsistent fertilization results in the finished product.
Granulation is the core production step. The mixed materials are conveyed to granulation equipment—typically a rotary drum granulator—where a fine water mist is sprayed. Through rolling friction, the materials agglomerate to form initial fertilizer granules. This process offers high formation rates and produces smooth, round granules; it is suitable for mass production and currently represents the mainstream method for compound fertilizer manufacturing.
The formed wet granules must undergo drying and cooling. They are fed into a drum dryer, where they are dehydrated in a constant-temperature hot air environment to reduce moisture content to below 2%. This step increases granule hardness and prevents caking. After high-temperature drying, the granules enter cooling equipment, where they are cooled to room temperature by natural airflow; this stabilizes the internal structure of the granules and enhances storage stability.
Finally, a two-stage screening process is performed. Vibrating screens are used to select standard granules within the 3–5 mm range. Oversized or undersized granules that fail to meet specifications are recycled for reprocessing—crushed and granulated again—thereby minimizing raw material waste. The qualified granules then proceed to the coating stage, where a specialized protective layer is applied to effectively prevent moisture absorption, caking, and nutrient loss, thereby extending the fertilizer's shelf life.
The final step involves packaging and warehousing the finished product. The coated compound fertilizer granules undergo automated quantitative filling, sealing, and coding to complete standardized processing before being moved to storage for sale. The entire production line features a high degree of automation and rigorous processing standards, ensuring consistent product quality while enabling efficient, energy-saving, and large-scale production.