There are a number of things you can see in the area.
A brown cloud of smoke above the BOS Plant
The BOS Plant has three converters. These are large drums we fill with red-hot pig iron. When oxygen is blown in, a chemical reaction takes place. That is how we make steel from pig iron. This produces a very foamy layer called slag. Sometimes that layer boils over, we call this slopping. This may cause a brown cloud of smoke above the BOS Plant. If this happens, we act very quickly. We are reducing roof emissions at the BOS Plant by means of an additional exhaust system, which is part of the Roadmap Plus.
A brown cloud above the Blast Furnaces
A brown cloud can also come out of the taphole of the Blast Furnaces. Such a cloud may occasionally appear when one of the tapholes opens or closes. We spray with water mist at the taphole to limit this effect. As part of the Roadmap Plus we reduce roof emissions by closing the tapholes more quickly. In addition, a new type of exhaust hood will be installed over the tapholes in both Blast Furnaces.
A cloud of steam at the Coking Plant
In the Coking Plant, we cook coal to make coke. We need coke to make pig iron. When the coke is 'done', we push it out of the ovens. The cooked coke is collected and doused with water from the extinguishing tower. This creates a visible cloud of steam. This is a standard process that takes place every 15 minutes.