The Mixing Stage: Different materials require different "mixing characteristics."

Horizontal mixers are suitable for the uniform mixing of powdery materials; the loading coefficient is typically controlled at 60%–70%, with a mixing time of 3–5 minutes. While their ribbon structure exerts strong pushing force on powders, it tends to crush granular materials. NPK blending machines operate quite differently; designed for finished granules—such as urea, ammonium phosphate, and potassium chloride—their primary objective is to achieve a uniform blend without damaging the granules. A dual-shaft paddle structure completes the mixing process in 2–5 minutes, achieving a coefficient of variation (CV) for uniformity of ≤5% and keeping granule breakage rates below 0.5%. For an entire NPK blending fertilizer production line, energy consumption is concentrated in the batching system's pneumatic gates, the mixer's main shaft, and the conveying equipment, rather than in the granulation stage.

Organic fertilizer double-axis mixers, meanwhile, must handle fermented materials that are highly viscous and fibrous. Two symmetrical spiral shafts rotate synchronously, creating three-dimensional convection within the chamber and achieving a mixing uniformity of over 95%. These mixers are usually equipped with a water-spraying humidification system that evenly applies water or binders during the mixing process, adjusting the material's moisture content for subsequent granulation. Insufficient mixing time leads to uneven moisture distribution, causing material to stick to the granulator pan; conversely, over-mixing causes fibers to wrap around the main shaft, resulting in a sharp spike in energy consumption.

The Drying Stage: The "temperature red line" for bio-organic fertilizers. The dryer is the most energy-intensive and high-risk piece of equipment in the bio-organic fertilizer production line. Since the survival rate of functional bacteria plummets when temperatures exceed 60°C, the drying process must employ a "low-temperature, high-airflow" strategy: an inlet air temperature of 60–80°C and a discharge temperature not exceeding 45°C. While trading temperature for higher airflow increases fan energy consumption, it preserves the viability of the bacterial strains. If the hot air temperature is raised to save electricity, massive bacterial die-off occurs, downgrading the product to ordinary organic fertilizer; the resulting loss in sales value far outweighs the savings on electricity costs.