Sponge iron production process

Introduction

There are four kinds of sponge iron production technology, such as rotay kiln method, shaft furnace method, vertical pot method and belt machine method. Taking the rotary kiln method as an example, the production process uses solid fuel as the reducing agent, the rotary kiln as the reactor.At the same time, the reducing agent and pellets are sent to the rotary kiln for reduction roasting. Generally, the degree of metallization can reach more than 90%.The sponge iron with a particle size of 5 ~ 15mm is usually used as a steelmaking raw material.

Process

The process of producing sponge iron by rotary kiln method mainly has 5 steps.

1.Raw material preparation

The main raw materials of sponge iron production by rotary kiln are iron ore and coal powder. These raw materials need to be prepared first, including ore grinding, coal drying and so on. At the same time, it is also necessary to add a small amount of expansion agent and binder in order to form a uniform pellet during the production process.

2.Pelletizing

The prepared raw materials are made into uniform pellets with a diameter of 5-25mm on the pelletizing machine. The particle size of pellets has an important impact on the production process and product quality, so it is necessary to strictly control the particle size when making pellets.

3.Preheating furnace

The prepared pellets are sent to the preheating furnace for preheating treatment. This step is mainly to enable the pellets to reach the appropriate temperature before entering the rotary kiln in order to fully decompose and reduce the consumption of pulverized coal.

4.Rotary kiln

The preheated pellets are sent to the rotary kiln for thermal reduction reaction. In a rotary kiln, the pellets are constantly rotated and heated, and through a series of chemical reactions, sponge iron is finally formed. A certain proportion of air also needs to be injected into the rotary kiln in order to play the role of oxidation and blowing the reaction product in the reaction.

5.Cool and crush

After the sponge iron is produced from the rotary kiln, it needs to be cooled and crushed. The main purpose of this step is to cool down and make the sponge iron block smaller, which is convenient for subsequent processing and application.