NPK compound fertilizer is a core fertilizer in modern agriculture. Its production process involves complex chemical reactions and material handling, and any oversight can affect product quality, production safety, and the ecological environment. Therefore, the following key points must be strictly controlled during the operation of the NPK fertilizer production line.

Raw material selection is the foundation of quality. The purity of nitrogen, phosphorus, and potassium raw materials directly determines the nutrient content of the fertilizer.  The content of impurities, heavy metals, and pollutants in the raw materials must be strictly tested. High-grade phosphate rock and other high-quality raw materials should be prioritized to prevent harmful components from affecting crop growth and soil health. At the same time, accurate raw material proportioning must be ensured, strictly controlling the nitrogen, phosphorus, and potassium ratio according to product specifications. Pre-production testing should be used to prevent problems such as moisture absorption and caking of raw materials, ensuring subsequent uniform mixing.
Process parameter control is a core link. The mixing stage requires professional equipment to achieve uniform blending of materials. The stirring speed and time should be adjusted according to the particle size and solubility differences of the raw materials to prevent local nutrient imbalances. The granulation stage is particularly critical. For example, in drum granulation, the moisture content of the slurry needs to be precisely controlled at 20%-25%, and the drum speed and tilt angle should be adjusted to ensure uniform particle formation and satisfactory hardness. The drying and cooling stages require controlling temperature and wind speed to prevent excessive moisture content or particle breakage, ensuring product stability.
Safety protection cannot be ignored. The acids and ammonia used in production are corrosive and toxic. Gas detectors and ventilation systems must be installed, and operators must be equipped with professional protective equipment. At the same time, process temperature and pressure must be strictly controlled to prevent slurry decomposition and hydrogen accumulation that could lead to fire and explosion. Hazardous areas should be demarcated, and safe distances maintained, and a comprehensive emergency response plan should be established.
Environmental protection is an essential responsibility. For waste gases such as fluorides and nitrogen oxides produced during production, scrubbers and dust collectors should be used for purification; wastewater needs to have its pH adjusted and pollutants such as phosphorus and suspended solids removed before discharge; by-products such as phosphogypsum should be classified and treated, prioritizing recycling to avoid polluting soil and water resources. In summary, NPK fertilizer production requires integrating raw material control, precise processes, safety protection, and environmental management throughout the entire process.  Only through standardized operations and strict supervision can high-quality fertilizers be produced, achieving a balance between economic and ecological benefits.