What is a pellet? It is a raw material for the production of pig iron. It is small pellets produced from iron ore and other additives that are hardened or baked. The pellet used in the direct regeneration method has a higher iron content and less impurity than the blast furnace pellet. The pellets used in the blast furnace must have a larger size and higher strength, which also depends on the size of the blast furnace. The degree of regeneration also depends on the degree of porosity, contact surface and gas solid contact.
Raw material for manufacturing
For the production of this product, crushed and ground iron ores with a grain size between 0 and 100 microns are supplied worldwide as pellet feed. These raw materials can be further ground in a short period of time for direct recovery units such as Ahvaz and Mobarakeh steel complexes. which are equipped with pelletizing equipment, are considered suitable cargo. In some direct regeneration processes, raw and hardened raw pellets are also used.
Raw materials for production include the following:
Method of production
First, the raw materials are poured into the pelletizing machine with a certain ratio. The reason for adding any of the additives is not outside the two factors of improving mechanical properties and metallurgical properties. The main significant mechanical property is their mechanical strength. The metallurgical properties that can be improved at this stage include the adhesion of raw materials to each other and facilitating regeneration in the blast furnace.
Efforts should be made to make the grade of iron ore used in raw materials closer to 69% hematite or 72% magnetite. Using high grade ore will save energy carriers.
In general, production methods are divided into cone and disk methods. Until the beginning of the 50s, the only method was the cone, which gradually became the main method of production on an industrial scale with the advancement of technology.