New process for iron production cuts emissions by 90 percent


November 16, 2006

November 17, 2006 A new manufacturing process developed appears set to make the production of iron much more environmentally friendly. The outstanding feature of the “Corex process” is that it uses conventional coal instead of coking coal, the customary ingredient. The world’s largest Corex-based plant is currently being built in China and is scheduled to begin operation in late 2007. It does not require a coking plant, reducing the discharge of dust and nitrogen oxides by more than 90 percent and sulphur dioxide emissions by 97 percent.

In conventional pig iron production at iron works, coking coal is first mixed with charge consisting of pellets, sinter and lump ore, and then the mixture is put into a blast furnace. At the base of this giant, bell-shaped furnace injected hot air burns the coking coal up into carbon monoxide at 2,000 degrees Celsius. In the upper part of the furnace the soaring carbon monoxide withdraws the oxygen from the iron oxide in the iron ore. Because of the high temperature the reduced ore melts to liquid pig iron. As a result of this traditional process with coking plant, powder metal facility and blast furnace, 1.4 kilograms of sulphur dioxide are created for each ton of pig iron. According to measurements taken by the TUV Rheinland, the Corex process sees this figure reduced to only 40 grams and the discharge of dust and nitrogen oxides is cut by more than 90 percent and sulphur dioxide emissions are reduced by 97 percent.

Corex is a smelting reduction process: Coal gasification, iron ore reduction, and liquefaction of the resulting iron are combined in one process. The gases produced can immediately be used for heating or for generating electricity in a gas and steam turbine power plant.

China’s booming economy and increasing urbanization are also leading to an upsurge of heavy industry. China’s metropolitan areas are now among the most polluted regions on earth, so new steel works are generally built with very environmentally friendly technology, and far from cities. Scheduled to become operational in the autumn of 2007, the new plant of the Baosteel subsidiary Baoshan in Luojing is expected to produce 1.5 million tons of pig iron per year using the Corex process. Baosteel is currently planning another Corex plant, also with a capacity of 1.5 million tons of pig iron.

About the Author
Mike Hanlon Mike grew up thinking he would become a mathematician, accidentally started motorcycle racing, got a job writing road tests for a motorcycle magazine while at university, and became a writer. As a travelling photojournalist during his early career, his work was published in a dozen languages across 20+ countries. He went on to edit or manage over 50 print publications, with target audiences ranging from pensioners to plumbers, many different sports, many car and motorcycle magazines, with many more in the fields of communication - narrow subject magazines on topics such as advertising, marketing, visual communications, design, presentation and direct marketing. Then came the internet and Mike managed internet projects for Australia's largest multimedia company, (Australia's largest Telco), (Australia's largest employment site),,, and a dozen other internet start-ups before founding Gizmag in 2002. Now he writes and thinks. All articles by Mike Hanlon
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