Pelletisation

Pelletisation, also known as pelletizing, is a process used in various industries to convert fine, powdered, or granular materials into small, spherical pellets. These pellets are typically formed by compacting the raw material under pressure, often with the addition of a binding agent, and then drying or hardening them. The technique is widely applied in metallurgy, agriculture, animal feed production, and chemical manufacturing.

In metallurgy, pelletisation is a key step in the production of iron ore pellets, which serve as a high-quality feedstock for blast furnaces. The process involves mixing finely ground iron ore concentrate with additives such as limestone and bentonite clay, which act as binders. The mixture is then rolled into small spherical pellets in a rotating drum or disc pelletizer. These pellets are subsequently hardened by heating in an indurating furnace, increasing their mechanical strength and resistance to degradation during transport and smelting.

In the agricultural and animal feed sectors, pelletisation improves the digestibility and nutritional value of feed by binding ingredients together. The process enhances the uniformity of the feed, making it easier to handle and store. Pellets are also used in pharmaceuticals to standardize dosage forms and improve stability.

The pelletisation process generally consists of several stages: preparation of the raw material, mixing with binders, forming pellets, and drying or hardening. The choice of equipment, such as drum or disc pelletizers, depends on the material properties and desired pellet characteristics. Modern pelletisation systems often incorporate automation to ensure consistency and efficiency. While the process offers numerous advantages, including improved material handling and reduced dust emissions, it requires careful control of parameters such as moisture content, pressure, and temperature to achieve optimal results.