Bleeder emissions are the release of an air emission from the blast furnace (through a safety relief valve). The visible emission contains primarily carbon and coal.
The emissions occurred while the Ironmaking teams were starting up the blast furnace after it was down during unusual circumstances in Steelmaking. Our steelmaking facilities and processes involve many interconnected and closed loop systems that our teams manage. In terms of Ironmaking, Blast Furnaces produce liquid iron for the KOBM and EAF steelmaking facilities. When a longer than planned shutdown occurred at the KOBM, the Ironmaking teams slowed production and rotated between our three Blast Furnaces to manage production balance, to avoid disposing liquid iron that is not needed (coffining) and to perform maintenance while Furnaces were down. The KOBM shutdown was extended to undertake a wider scope of maintenance work than what was initially planned.
Note that our Blast Furnaces also supply fuel (Blast Furnace Gas) to our Cokemaking facilities, and during this unplanned extension of work at the KOBM, this gas was interrupted. This interruption causes a need for longer coking (baking) times, which can also cause an increase in visible emissions from the coke stacks.
We appreciate those who have reached out with regard to this issue. Our Ironmaking and Environment teams have stabilized the furnace and are investigating the cause and assessing any potential impact. They also notified the Ontario Ministry of Environment, Conservation and Parks immediately and accordingly. Follow up communication will be undertaken as needed.