Notice of Incident

UPDATE December 25, 2020 6:05 p.m.

The incident was a series of eruptions that occurred during the Slag Casting process – when slag and molten iron from the Blast Furnace are separated and the slag is cast. In this case liquid slag / iron came into contact with moisture which caused the eruptions. (The Blast Furnace produces liquid iron used in steelmaking. Slag, a byproduct, is cast, then pelletized and used in aggregate applications).

The reaction was between water and primarily liquid iron and would have been comprised of mostly iron, iron oxide and water vapour, as well as silica, calcium, magnesium, carbon dioxide, and carbon monoxide. 

ORIGINAL POST December 25, 2020 12:20 p.m.
At approximately 11:10 a.m. a slag pit eruption occurred at the No. 4 Blast Furnace. Thankfully there are no injuries. However the event caused a significant air emission. Ministry of Environment, Conservation and Parks have been alerted.

Both ArcelorMittal and Hamilton Fire attended. Hamilton Fire has now left. The site is secure.

We will provide an update when available.

About ArcelorMittal Dofasco

About ArcelorMittal Dofasco ArcelorMittal Dofasco is Canada’s largest producer of flat carbon steel and is part of the world’s largest steel and mining company. Headquartered in Hamilton, ON, our more than 5,000 employees are dedicated to being world class as we strive to transform tomorrow with lighter, stronger and more sustainable steel. For us, steel is the fabric of life, as it is at the heart of the modern world. ArcelorMittal has a presence in more than 60 countries and an industrial footprint in over 20 countries. Guided by a philosophy to produce safe, sustainable steel, we are the leading supplier of quality steel in the major global steel markets including automotive, construction, household appliances and packaging, with world-class research and development and outstanding distribution networks. For more information about ArcelorMittal Dofasco, please visit:

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