ArcelorMittal: Dust control in Belgium
Challenge
|
|
The steel production process undoubtedly has an impact on the environment, and one area of concern is steel dust.
In the steel shop, hot metal is converted into liquid steel through the oxidation of carbon and other elements, and impurities are removed. Pure oxygen is blown onto the hot metal bath and the combustion process takes place in the converters – two gigantic tanks.
This process generates a large amount of dust-rich flue gas. If the steel dust escapes, it poses health risks and is an environmental nuisance.
Action
ArcelorMittal Gent has adapted its steelmaking processes to limit the amount of dust they emit. Each converter is equipped with a primary dust removal installation that extracts the flue gases generated within it. Some gases, however, develop when the converter is tilted – while loading it with scrap and hot metal and while casting the liquid steel – and escape the primary dedusting unit.
Previously, these gases were scrubbed with water before being discharged via chimneys. In 2004, ArcelorMittal Gent commissioned a secondary dedusting unit for the steel shop. This unit consists of an aerodynamic exhaust hood with an extraction rate of 2.4 million m3 an hour, leading to one major collector pipe. The flue gases are sent through this pipe, and a battery of 7,200 filter sleeves collect the dust. Eventually, the purified flue gases are discharged through a 45-metre high chimney.
Outcome
The secondary dedusting unit has reduced dust emissions by over 95% at a cost of 30 million euro. With a total investment of almost 100 million euro in dust control between 1988 and 2006, ArcelorMittal Gent continues to make dust control a priority.
Last updated: June 2010
