How does an organic fertilizer production line operate?

An organic fertilizer production line transforms organic waste—such as livestock manure and crop straw—into commercial organic fertilizer ready for direct application. It is a continuous process that integrates biological fermentation with mechanical processing. The core logic follows the principle of "fermentation first, then granulation," which can be broken down into the following stages:

Stage 1: Raw Material Pretreatment. At the start of the production line, manure, straw, auxiliary materials, and fermentation microbial agents are mixed according to a specific formula. Straw is typically shredded by a crusher to an appropriate particle size, which increases its specific surface area and adjusts the carbon-to-nitrogen (C/N) ratio, creating optimal conditions for subsequent fermentation.
Stage 2: Aerobic Composting/Fermentation. The mixed materials are placed into a compost turning machine or fermentation tank. Through forced ventilation and periodic turning, microorganisms are encouraged to proliferate rapidly under controlled temperature and humidity. The temperature of the compost pile is raised to 55–65°C and maintained for several days; this effectively eliminates pathogens and insect eggs while breaking down complex organic compounds into stable humus. The fermentation cycle generally lasts 15–25 days and is the critical phase that determines the fertilizer's efficacy.
Stage 3: Crushing and Screening. After fermentation, the material may contain clumps. It is passed through a crusher to refine the particle size, followed by a rotary or vibrating screen to remove stones and debris, resulting in a semi-finished product with uniform particle size.
Stage 4: Ingredient Blending. Based on the target nutrient content, an automated batching system adds inorganic nutrients (such as nitrogen, phosphorus, and potassium) along with secondary and trace elements. These are thoroughly blended in a mixer to ensure that every fertilizer granule has a consistent composition.
Stage 5: Granulation. The uniform powder is fed into a disc granulator or a new type organic fertilizer granulator, where it is rolled and agglomerated into spheres with the aid of water and binding agents. Particle size can be adjusted by modifying the equipment's tilt angle, rotational speed, and the amount of water sprayed. Once formed, the moist granules pass through a dryer to remove excess moisture, followed by a cooler to lower their temperature and set their final structure. Stage 6: Screening and Coating. The cooled granules undergo a second round of screening. Those that meet the required particle size specifications are fed into a coating machine, where they are encased in an anti-caking agent to enhance both granule strength and storage stability.
Stage 7: Weighing and Packaging. The finished product is automatically weighed, bagged, and sealed according to specific requirements. A palletizing system then prepares the bags for removal from the production line, moving them into storage in anticipation of shipment.

In summary, an organic fertilizer production line—comprising a closed-loop process of fermentation, crushing, ingredient blending, granulation, drying, screening, and packaging—achieves three key objectives: the repurposing of waste, the precise management of nutrient content, and the commercialization of the final product. This delivers both environmental and economic benefits. Depending on the specific raw materials and production capacity requirements, enterprises can flexibly select and integrate individual pieces of equipment—such as compost turners, dryers, and coating machines—to create a customized production line solution.