Smelting processes produce a molten iron product and slag containing gangue material. The molten product can be used directly in the steel making process or solidified into pig iron for sale as a merchant product. As the smelting processes go through a melting phase, gangue materials are eliminated from the iron product with the use of fluxes to produce a slag. The iron may contain impurities which are soluble in iron, eg sulfur and phosphorus, which may require further processing before being suitable for the production of steel. Some steel making processes, eg Q-BOP, can handle elevated levels of phosphorus.
The blast furnace and mini blast furnace are mature technologies and lead the field of smelting processes as they are the main commercial producers of iron for the steel industry. There is opportunity to challenge this technology, especially where new plant is required. Blast furnace technology requires a lump or agglomerated iron oxide and coke, which makes it considerably less flexible than new smelting technologies like HIsmelt, Corex, Technored and ITmk3.
Smelting processes can be categorized into the following groups:
- Shaft Furnaces
- Melter Gasifiers
- Iron Bath Reactors
- Slag Bath Reactors
- Rotary Hearth Processes
- Other Processes