NPK compound fertilizer is a primary, balanced fertilizer used in agricultural production. Leveraging mature process technology, Huaqiang Heavy Industry offers complete NPK fertilizer production lines that balance formulation flexibility, production stability, and granule quality—ideally suited for large-scale compound fertilizer manufacturing. The production line utilizes a closed-loop design, encompassing automated batching, crushing and mixing, granulation, drying and cooling, screening, coating, and final packaging. A recycle system ensures the reuse of materials, thereby minimizing raw material loss.

The process begins with an automated batching system that precisely measures raw materials—such as urea, monoammonium phosphate (MAP), and potassium chloride—ensuring a stable NPK ratio. These materials are then thoroughly blended in a twin-shaft mixer, achieving high uniformity, which is essential for the subsequent granulation stage. The granulation process primarily employs a rotary drum steam-agglomeration method: as materials roll continuously within the drum, steam is introduced to adjust the liquid phase, causing the powder particles to adhere and agglomerate into granules. The resulting wet granules are fed into a rotary dryer, where a counter-current flow of hot air removes excess moisture. They are then cooled to prevent caking caused by high temperatures. A screening system separates the product into qualified granules, fine powder, and oversized particles; the fines and crushed oversized material are returned to the granulation stage, completing the closed-loop production cycle. Qualified granules may undergo an anti-caking coating process before being automatically packaged for storage.
This granulation process offers several distinct advantages. First, it demonstrates high adaptability to various raw materials, allowing for the flexible production of high-, medium-, and low-concentration NPK formulations, with the option to incorporate secondary nutrients and micronutrients to meet the specific fertilization needs of field crops, fruits, and vegetables. Second, it ensures consistent granulation, producing uniform, spherical, and high-strength granules that are resistant to breakage and dust generation during storage and transport, which effectively reduces nutrient loss. Third, the process offers excellent continuity and high individual equipment capacity, making it well-suited for stable, large-scale production in medium-to-large fertilizer plants; the equipment also features a low failure rate and is easy to maintain. Fourth, the process offers high controllability; by adjusting steam volume, rotational speed, and material residence time, particle size can be precisely regulated to meet market standards. Furthermore, a closed-loop material recirculation design enhances raw material utilization, while an integrated dust removal system improves the workshop environment, aligning with green production requirements.
Compared to other granulation methods, the drum granulation process is technologically mature and highly cost-effective. The resulting granules exhibit consistent slow-release characteristics, ensuring a steady nutrient release after application; this facilitates balanced uptake of nitrogen, phosphorus, and potassium by crops, thereby improving fertilizer use efficiency. Huaqiang Heavy Industry’s NPK production line balances practical process operation with high product quality, serving as a reliable solution for the industrial-scale production of compound fertilizers.