The Redsmelt process is based upon a rotary hearth furnace which reduces green pellets made out of iron ore, reductant fines and binders to produce hot, metallized DRI that is charged to a Submerged Arc Furnace. The process operates at high temperature and atmospheric pressure.

The iron ore is fed to a Redsmelt furnace in the form of green pellets made of fine iron ore, reductant and binders. After size screening, pellets are charged into the RHF in layers up to 30 kg/m². While traveling throughout the furnace in 12 to 18 minutes, pellets are heated up to 1370 °C and drying of the pellets, devolatilization of coal and iron ore reduction takes place. To prevent reoxidation of metallized iron the final zones of the furnace are operated in sub-stoichiometric atmosphere. The hot DRI product is then fed to the submerged arc furnace (SAF) for smelting into Hot metal and slag.