Pig Iron production at a lower temperature
Pig iron is an integral, but wasteful building block of steel. Until recently, the only commercially viable way to get molten pig iron was to super-heat iron ore, a process that proved energy inefficient, expensive and harmful to the environment due to the amount of coal and the high temperatures used to melt the iron. In an effort to relieve some stress on the environment and cut production costs, two Dutch inventors, Koen Meijer and Huib den Hartog, discovered a new way to produce pig iron at a low temperature.
At a glance
Inventor(s): Koen Meijer, Huib den Hartog
Invention: Cyclone Converter Furnace (CCF)
Company: Corus belonging to Tata Steel Group
Before Meijer and den Hartog developed their innovative "Cyclone Converter Furnace (CCF)," one way to produce molten pig iron was to melt iron ore with charcoal or "coke" and limestone in a blast furnace, with the pig iron then transferred in its liquid form to the steel plant. Once at the plant, the pig iron was then converted into steel by burning off excess carbon.
Den Hartog, who is now retired, and Meijer who works for Corus, Europe's second-largest steel manufacturer with approximately ₤12 billion in annual revenue and production of over 20 million tonnes of steel annually, knew there had to be a more cost-effective and environmentally-friendly process in pig iron production.
In 2001, Meijer and den Hartog created their CCF, which made it possible to produce molten pig iron directly from iron ore and coal using low temperatures through a two-step process using a melting cyclone for the pre-reduction stage and metallurgical vessel for the final reduction stage.
Both stages make use of the gasses released during reduction, allowing lower temperatures and a smaller amount of coal, which means less energy is used.
Moreover, they discovered a way to incorporate the slag layer, a solid waste by-product of producing pig iron, into the melting process. Using slag in the production process was a novel idea and proved to be a greener slag-disposal method.
Meijer and den Hartog's CCF, uses 500 to 1 000 kilograms of coal per tonne of pig iron produced, much less than what is needed in the traditional melting process. The smaller amount of coal significantly reduces costs and saves environmental wear-and-tear.
With pig iron being the key ingredient in steel production and steel being the key to the modern building process, it is impossible to overstate the value of pig iron in industrial progress. The Meijer and den Hartog design as part of future ironmaking processes is good news for both steel manufacturers looking to cut costs and for the environment.