Cold Briquetted Iron (CBI)

During the steel production where Sponge Iron (DRI) is applied as a raw material, large quantities of undersized particles and fine are made which are not useful to be used in steelmaking. These metallic particles and fines are formed into the briquettes using sodium silicate (Na₂SiO₃) as the binder and lime as the flux. The formed briquettes are referred to as cold briquetted iron (CBI) since they are compacted while the fines are cold.

In other words, cold-molded briquettes produced from fines and by-products, that generated during the process of production, storage, and handling of DRI are known as “Cold Briquetted Iron (CBI)” in direct reduction (DR) industries.

Besides boosting fines utilization, the cold briquetting system has been happened to be a very significant development in handling and storage of DRI (sponge iron).

Working principle

Feed the raw material to the hopper on top of the roller press, then it will go to the lower roller pressing area through gravity or a force feeding system.

In this roller pressing area, there are two same pressing rollers with ball-pockets on the surface, which rotate at a constant but opposite speed. When the material enters the bite angle between the two rollers, it is gradually compressed as the bite angle is reduced. At the moment when the two ball-pockets coincide, the briquetting pressure reaches a maximum and briquette is made. then, the two ball-pockets are opened and the briquette begins to elastically expand and fall off.

In the roll briquetting press machine, the raw material is pressed on both sides, and the pressure from each roller is the same.