The Superstack, as it’s known, is owned by Brazil-based Vale and is part of the mining company’s Copper Cliff processing facility. At 381 metres tall it is in Canada second only to the 533-metre CN Tower in height, and would loom over even The One, a 306-metre building under construction at Toronto’s Yonge/Bloor intersection, and destined to be Canada’s tallest building when completed.
The Superstack is the tallest chimney in the Western hemisphere, the second-tallest freestanding chimney in the world (after one in Kazakhstan) and the 51st tallest freestanding structure on Earth, with most of the others being skyscrapers rather than chimneys or towers. (Also, a freestanding structure is one that supports and steadies its own weight, as opposed to being anchored by guy wires.)
It’s also no longer in use. Built in 1970 and fully operational two years later, the smokestack was taken out of service in 2020 after the company cut sulphur dioxide emissions at the Copper Cliff Complex by 100,000 tonnes per year, in line with provincial limits. Now it’s coming down.
From the article: