DRI-Direct Reduced Iron

DRI-Direct Reduced Iron

Direct Reduced Iron (DRI-Direct Reduced Iron) is a low-carbon porous substance formed by the reduction of refined iron powder or iron oxide at a low temperature in a furnace. Its chemical composition is stable and its impurity content is low. As a coolant for converter steelmaking, it can also be used for powder metallurgy after secondary reduction.

The production process of DRI can be divided into the following five processes:

1. Raw material preparation and drying and crushing process:

Two kinds of materials, desulfurizer and reducing agent, are loaded into the quantitative hopper, and the quantitative hopper sends the materials to the drying chamber through the conveyor according to the weight ratio of the two materials to dry and mix the two materials. The moisture content of the dried material is less than 3%. The dried material is sent to the reducing agent crusher through the conveyor for crushing, and the crushing particle size is below 1.5mm. The crushed materials are lifted to the high-level silo by the conveyor, and then sent to the storage silo by the conveyor. The concentrate powder is directly sent to the drying unit by the conveyor for drying. After drying, the moisture content is less than 3%. The dried concentrate powder is sent to the high-level silo by the conveyor, and then sent to the storage material by the conveyor. warehouse.

2. Automatic loading process:

This process can produce barrel-shaped, column-shaped or tile-shaped direct reduced iron as required. The charging system is composed of three parts: silo, quantitative pipe and charging head. The concentrate powder and reducing agent are discharged into the distribution silo through the storage silo, and then loaded into each reducing crucible by the charging head to realize the charging process. Crucible Cloth.

3. Reduction roasting process:

This process is completed in a rapid reduction furnace. Appropriate and stable furnace temperature and reduction time are the key to determining the quality of DRI. This process includes three stages: preheating, reduction and cooling. First, the truck passes through the transmission mechanism and sends the truck into the preheating section of the rapid reduction furnace. During this time, the moisture in the material is completely evaporated, the desulfurizing agent is decomposed, the temperature rises to the reduction temperature, and the high temperature reduction section enters the high temperature reduction section. The iron oxide is fully reduced to form elemental iron, and then enters the cooling section for cooling, and is cooled to below 200 °C before being released from the furnace.

4. Automatic unloading process:

After the material is released from the furnace, it will drop to 100 ℃ ~ 50 ℃ at room temperature and then enter the unloading system for unloading. The ash is sucked away by the wind, and the direct reduced iron is taken away from the crucible by the grasping tongs, realizing automatic unloading.

5. Product processing procedure:

This process completes the direct reduced iron magnetic separation, crushing and passivation treatment - briquetting. The unloaded truck enters the loading system for loading. The DRI enters the intermediate silo through the unloading device. The DRI in the intermediate silo is transported to the DRI crusher for crushing through the conveyor. The crushed DRI is magnetically separated by the dry magnetic separator, and the DRI powder after magnetic separation is transported by the conveyor to HDYJ for reduction. The iron briquetting unit is used for briquetting and storage through the transmission mechanism.

The realization of cold briquetting effectively improves the oxidation resistance of DRI. It reduces the water absorption of DRI and reduces the volume, which is beneficial to the long-term storage and long-distance transportation of DRI. At the same time, it also improves the yield of molten steel when used. Therefore, it is very popular among steel-making enterprises. In the market competition It has strong vitality and competitiveness.