Direct reduced iron (DRI)
Direct reduced iron (DRI), also called sponge iron, Is produced from the direct reduction of iron ore (in the form of lumps, pellets, or fines) to iron by a reducing gas or elemental carbon produced from natural gas or coal. Many ores are suitable for direct reduction.
Direct reduction refers to solid-state processes which reduce iron oxides to metallic iron at temperatures below the melting point of iron. Reduced iron derives its name from these processes, one example being heating iron ore in a furnace at a high temperature of 800 to 1,200 °C (1,470 to 2,190 °F) in the presence of the reducing gas syngas, a mixture of hydrogen and carbon monoxide.
Hot Briquetted Iron (HBI)
Hot Briquetted Iron (HBI) is a premium form of DRI that has been compacted at a temperature greater than 650° C at time of compaction and has a density greater than 5,000 kilograms per cubic metre (5,000 kg/m3).
HBI was developed as a product in order to overcome the problems associated with shipping and handling of DRI – due to the process of compaction it is very much less porous and therefore very much less reactive than DRI and does not suffer from the risk of self-heating associated with DRI.
The principle market for HBI is electric arc furnace (EAF) steelmaking, but HBI also finds application as a trim coolant in basic oxygen furnace (BOF) steelmaking and as blast furnace feedstock