Analysis of dry granulation and wet granulation processes in organic fertilizer production lines

In organic fertilizer production lines, dry granulation and wet granulation are the two core processes of granulation, each with its own advantages, providing perfect solutions for different needs.

Dry granulation relies on strong mechanical pressure to press dry powder with low moisture content into flakes and then crush and screen. Its operation does not require additional water or binders. When processing low-viscosity materials such as fermented organic fertilizer dry powder and phosphate rock powder, it can retain the effective ingredients in the raw materials to the greatest extent. The particles have high firmness, strong storage resistance, and less loss during transportation, which greatly reduces logistics costs. The equipment investment cost is low, the operation is simple, and a small amount of manpower can be easily handled, which is very suitable for small and medium-sized production such as village-level cooperatives. Especially for water-sensitive materials such as biological organic fertilizers, it can well retain the active bacteria in them and ensure the efficacy of the fertilizer.

Wet granulation increases the moisture content of the material by adding water or binders, and agglomerates into balls under mechanical force and then dries. For high-humidity materials such as poultry and livestock manure and municipal sludge, they can be processed directly without pre-drying, eliminating many pretreatment steps. The particles are round and smooth, with good fluidity during mechanized fertilization, which can reduce equipment blockage problems. It is suitable for the production of high-value-added fertilizers, and the coating uniformity is better than the dry method, which can significantly improve the quality of fertilizers. Although the drying process will produce exhaust gas, it can meet the emission standards after being equipped with corresponding environmental protection equipment, and it has outstanding efficiency in large-scale production, which can meet high production capacity requirements.

The selection of process can be based on the raw materials: wet method for materials with high moisture content, and dry method for dry powder or bacteria-containing materials. For high-quality fertilizers, you can choose a rotary drum granulator or a disc granulator. If the budget is limited and the production capacity demand is small, choose a double roller press granulator. The two processes each have their own strengths, helping to improve the quality and efficiency of organic fertilizer production, and there is always one that meets your needs.