The production of blended fertilizers (BB fertilizers) involves mixing multiple basic fertilizers in specific proportions to create compound fertilizers containing nutrients such as nitrogen, phosphorus, and potassium. Its production process is relatively simple, but strict control of raw material ratio and mixing uniformity is required. The following are the detailed steps and key points of mixed fertilizer production:

　　1、 Preparation before production

　　raw material selection

　　Basic fertilizers: urea (nitrogen source), monoammonium/diammonium phosphate (phosphorus source), potassium chloride/potassium sulfate (potassium source), etc.

　　Trace elements: Add zinc sulfate, borax, magnesium sulfate, etc. as needed.

　　Fillers: such as bentonite and talc powder (to adjust particle size and prevent clumping).

　　Requirement: The raw materials should be dry, free of impurities, and have uniform particle size (usually 2-4mm) to avoid layering during mixing.

　　formulation design

　　Determine the ratio of nitrogen, phosphorus, and potassium (such as 15-15-15, 20-10-10, etc.) based on crop demand and soil testing results.

　　Use professional software or empirical formulas to calculate the amount of each raw material used, ensuring that the nutrient content meets the standard.

　　Equipment inspection

　　Check if the mixer, conveyor belt, packaging machine and other equipment are clean and functioning properly.

　　Clean up residual fertilizers to avoid cross contamination.

　　2、 Production process

　　1. Raw material pretreatment

　　Crushing and screening: If the particle size of the raw material is uneven, it needs to be crushed by a crusher and then screened by a screening machine to obtain particles that meet the requirements.

　　Drying: If the moisture content of the raw material is too high (>2%), a dryer should be used to reduce the moisture and prevent clumping.

　　2. Ingredients

　　Artificial ingredients: suitable for small-scale production, weigh each raw material according to the formula and pour it into the mixer.

　　Automatic batching:

　　Use electronic scales and PLC control systems to automatically transport raw materials to the mixer according to preset proportions.

　　Advantages: High precision (error<0.5%), high efficiency, suitable for large-scale production.

　　3. Mixing

　　Equipment selection:

　　Horizontal mixer: suitable for dry material mixing, with high mixing uniformity (CV<5%).

　　Vertical mixer: Small footprint, but low mixing efficiency.

　　Mixing time: usually 5-10 minutes to ensure that each component is fully and evenly mixed.

　　Notes:

　　Avoid overloading the mixer and prevent uneven mixing.

　　After mixing, it is necessary to take samples to test the nutrient content to ensure compliance with the formula requirements.

　　4. Anti caking treatment (optional)

　　Add anti caking agents such as diatomaceous earth, mineral oil, etc., spray on the surface of fertilizers to reduce moisture absorption.

　　Cooling: If the temperature rises during the mixing process, a cooling machine should be used to reduce the temperature and prevent clumping.

　　5. Packaging and Storage

　　Packing:

　　Use an automatic packaging machine to pack fertilizers into woven or plastic bags (usually 25-50kg/bag).

　　The seal should be tight to prevent moisture.

　　Storage:

　　Store in a dry and ventilated warehouse, away from direct sunlight.

　　The stacking height should not exceed 5 layers to prevent crushing.