Composting is the core process of converting organic waste into high-quality fertilizer in an organic fertilizer production line. It requires multiple meticulous operations to ensure that the raw materials are fully decomposed and retain effective nutrients.
Raw material proportioning and mixing are the initial steps in composting. Livestock and poultry manure, crop straw, and edible mushroom residue are mixed in appropriate proportions to adjust the carbon-nitrogen ratio and moisture content to create a suitable environment for microbial activity. Mixing must ensure uniform distribution of the raw materials to avoid local imbalances that could affect fermentation. A double axis mixer is typically used for efficient mixing, laying the foundation for subsequent fermentation.
Feeding the fermentation silo and initial fermentation are critical stages. The mixed raw materials are transported to the fermentation silo, forming a pile of a certain height. During this stage, a ventilation system controls oxygen levels, and a heating device gradually raises the pile temperature. As microorganisms multiply and metabolize, the pile temperature naturally rises. High temperatures kill pathogens and weed seeds, accelerating the decomposition of organic matter. This process typically lasts several days.
Turning and secondary fermentation optimize the fermentation environment. When the pile reaches a certain temperature and becomes partially compacted, it is turned using compost turning equipment. Turning the compost breaks up compaction, ensuring more even oxygen distribution within the compost, and moving under-fermented materials from the outer layers to the inner layers, ensuring uniform composting maturity. Turning frequency should be adjusted flexibly based on the compost temperature and humidity. After repeated turning, the compost enters secondary fermentation, further degrading recalcitrant organic matter.
Composting and post-processing complete the process. When the compost temperature drops close to ambient temperature, the material appears dark brown, and has no noticeable odor, it is considered nearly mature. After composting, screening is required to remove impurities and incompletely decomposed bulk materials, resulting in a uniformly textured semi-finished organic fertilizer that can be directly used for subsequent granulation, drying, and other processing steps, ultimately becoming a qualified organic fertilizer product.
The entire process is closely linked, and the quality of each step directly impacts the quality and production efficiency of the organic fertilizer. Scientific management and control are essential to ensure an orderly process.
