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It is the small pellets produced from soft iron ore and other additives, which are first raw and then cooked and hard; And for regeneration in the traditional method of iron production in blast furnace or many other methods, direct regeneration is used. Pellet is a kind of raw material for the production of raw iron, which cannot be used in place of fine-grained iron ores in this physical form.

Pellet is one of the raw materials used in the production of steel sections, which is made using a powder obtained during the extraction process or crushed iron ore. After crushing, iron ore is used as a concentrate to make pellets. To obtain iron ore concentrate, it removes impurities and increases its iron grade compared to mined iron ore. The size of the particles should be no more than 45 microns.

The pellet is the result of combining iron ore concentrate with additives

Types of pellets

In general, iron pellets are divided into the following 4 categories:

Large pellet: One of the most widely used types of pellets in the cement and steel industry is the large pellet, which is produced in various diameters between 20 and 30 mm.

Normal pellets: In the classification of pellets based on size and types, those with a diameter of 10 to 15 mm are introduced as normal pellets. Normal pellets are most commonly used in direct regeneration units of blast furnaces

Small balls: the smallest types of balls with diameters of 3 to 8 mm are used in making lumps, and this category of iron balls is known as small balls in the market.

Sponge ball: Sponge ball has a spherical structure and Iranian steel factories produce it in different sizes. The most application of this type of pellet can be seen in industries based on scrap metals and casting

Specifications and physical and chemical characteristics of pellets

What we know as pellets is actually the result of combining iron ore concentrate with additives that have adhesive properties and cause the following physical and chemical properties in pellets.

Increasing pellet porosity

Pellet is one of the most widely used raw materials in the blast furnace and is used in the production of steel products by the direct regeneration method. Because the components used in pellet production increase the degree of porosity, contact surface and solid contact and increase the regenerability of iron. Porosity of all types of pellets is usually between 25 and 30%

decrease

 density

 pellet

 iron

One of the effects of pellet components on its physical properties is the reduction of density. There is always an inverse relationship between porosity and density. Therefore, as the porosity increases, the pellet density decreases

Create slag

One of the products of the pelletizing process is slag. Slag is also a combination of silicate and complex metal oxides, which after cooling, is used in solid form in various applications such as road infrastructure materials, refractory materials, railway ballast, asphalt and concrete stone materials, etc.

Facilitating the pelleting process

Additives used in making pellets adjust the metallurgical properties of the balls and act as a strong glue to create pellet pieces.

Increasing pellet strength

In fact, these are compounds like bentonite that bind the compounds and components used in making balls together and make the balls strong. These pellets show high strength even against heat stress in regenerating environments

Pellet is used as raw material to produce pig iron. Fine-grained iron ores cannot be used because they reduce the gas permeability in the blast furnace load unevenly and cause malfunction of the furnace. That’s why they turn into pellets.