Direct Reduced Iron (DRI) Process
Direct reduced iron (DRI) is defined as iron ore (in the form of lumps, pellets or fines) that has been reduced to metal without melting it. This process is also known as “direct iron reduction” and is a naturally occurring phenomenon. It is normally carried out in a reduction furnace and involves the use of carbon to reduce the iron oxide present in the ore.
The process of direct reduced iron (DRI) has many different applications. It can be used to make sponge iron, which is the foundation of producing steel for structural applications. DRI is also used to reduce the amount of nitrous oxide emissions when producing certain types of steel. Additionally, DRI may be used to reduce energy costs, increase the yield of scrap steel, improve the surface finish on steel products, and reduce the amount of scrap generated.
The direct reduced iron (DRI) process employs a closed-loop oxidation reaction, in which oxygen is used to react with iron oxide present in the iron ore. The result of this oxidation process is iron oxide, gas and water. The iron oxide and gas then combine to form iron and carbon monoxide, which is released as smoke.
When making DRI, a special type of furnace, called a reduction furnace, is used. This furnace consists of several chambers, which are connected to the atmosphere and the drying equipment, which is used to keep moisture away from the material being reduced.
The operation of a reduction furnace is relatively simple. The furnace is filled with iron ore and carbon in the form of coke, sawdust or charcoal, which is then heated to a temperature of about 1400 degree Celsius. In the presence of oxygen, the iron ore is heated and the oxygen combines with carbon and iron, reducing the iron ore to pure iron. The reduction process usually takes between 16 to 18 hours, during which the furnace door must remain shut in order to control the reduction reaction.
Once the reduction process is complete, the iron ore is then cooled and sent for further processing. Depending on the type of DRI being produced, the cooled iron can be further processed to create different grades of steel. Common methods used in the refining of DRI include arc furnace melting, acid leaching, and solidification of the iron.
In conclusion, direct reduced iron (DRI) is an effective way of producing steel from iron ore. This process relies on the oxidation reaction between oxygen and iron oxide in the iron ore. Through the use of a reduction furnace, the oxide and gas are then combined to form iron and carbon monoxide, which is released as smoke. After cooling, the iron is then ready for further processing to produce different grades of steel.
