In the context of carbon reduction and emission reduction, the new process of electric arc furnace (EAF) steelmaking based on direct hydrogen reduction is an important potential method for the green and sustainable development of the steel industry. Within an electric furnace for the hydrogen-based direct reduction of iron, after hydrogen-based directly reduced iron (HDRI) is produced through a shaft furnace, HDRI is melted or smelted in an EAF to form final products such as high-purity iron or high-end special steel. As smelting proceeds in the electric furnace, it is easy for pieces of HDRI to bond to each other and become larger pieces; they may even form an “iceberg”, and this phenomenon may then worsen the smelting working conditions. Therefore, the melting of HDRI is the key to affecting the smelting cycle and energy consumption of EAFs.

First, using a certain proportion of DRI in the smelting process of high-quality steel in EAF can improve the mechanical properties and overall quality of high-quality steel. At the same time, reasonable control of the application proportion of DRI can achieve the purpose of energy saving and increase in production, which is of great significance to improving the comprehensive benefits of EAF steelmaking. Second, the application of DRI in BF steelmaking can reduce the coke ratio of BF steelmaking and increase the output of BF steelmaking. The economic benefits of BF steelmaking are greatly improved.

To further enhance DRI for steelmaking, it can be converted to pig iron or hot metal via melting. There are existing processes in the industry that use electric energy in furnaces such as submerged arc furnaces to convert DRI into hot metal. Air Products’ novel DRI melting process uses oxy-fuel combustion in place of electric power to accomplish this melting. Figure 4 provides a process diagram (patent pending) .

Advantages of charging DRI hot coming out of the shaft reactor have been well documented, namely productivity increase and decrease in power use. Few DRI plants in the world have the ideal setup with an EAF downstream of the DRI plant, where the DRI coming out of the shaft furnace can be charged hot into the EAF.

Direct Reduced Iron (DRI) is the second most viable source of virgin iron used in steelmaking after pig iron or hot metal produced in blast furnaces. DRI is produced by direct reduction of iron ore using carbon monoxide and hydrogen. Natural gas-based shaft reactors are commonly used in North and South America for DRI production while coal-based DRI is common in Asian markets. Inexpensive supply of natural gas in the United States makes DRI an attractive source of iron for steelmakers.