The Two Primary Types of Granulation in Fertilizer Manufacturing

Granulation is a critical process in fertilizer manufacturing that transforms fine powder raw materials into granular forms, enhancing handling, storage, and application efficiency. There are two primary types of granulation techniques in this industry: Dry Granulation and Wet Granulation. The fundamental distinction between the two lies in whether a liquid solution or binder is employed during the granulation process. Each method boasts unique processes, applicable scenarios, equipment requirements, and advantages and disadvantages, making them suitable for different production needs and fertilizer formulations.

Dry Granulation, also known as extrusion granulation, relies solely on mechanical pressure to bond powder particles, without the addition of water or any liquid binders. The process starts with raw materials that have low moisture content, typically below 10%. These dry powders are fed into a double roller extrusion granulator, where they are squeezed between two counter-rotating rollers under high pressure. This intense mechanical force compacts the powder into dense sheets or "slugs." Subsequently, these slugs are crushed into smaller particles and screened to obtain granules of the desired size. This method is particularly well-suited for moisture-sensitive or heat-sensitive fertilizers, as the absence of liquid and heat prevents nutrient degradation. It is also an ideal choice for small-to-medium-scale production operations.