Inco Superstack

Inco Superstack
The Vale-Inco (former Inco) Superstack at the Inco Copper Cliff smelter
Map
Alternative namesVale Superstack
Record height
Tallest in World from 1971 to 1987[I]
Preceded byMitchell Power Plant
Surpassed byEkibastuz GRES-2 Power Station
General information
TypeChimney
Town or cityGreater Sudbury
CountryCanada
Coordinates46°28′48.23″N 81°3′23.43″W / 46.4800639°N 81.0565083°W / 46.4800639; -81.0565083
Construction started1970
Completed1972
Cost$25 million ($160 million inflation adjusted)
OwnerVale Limited
Height381 m (1,250 ft)
Dimensions
Diameterat base: 35 m (115 ft)
at top: 16 m (52 ft)
Technical details
MaterialReinforced concrete with stainless steel liner
References
[1]

The Inco Superstack in Sudbury, Ontario, with a height of 381 metres (1,250 ft), is the tallest chimney in Canada and the Western Hemisphere, and the second-tallest freestanding chimney in the world after the Ekibastuz GRES-2 Power Station in Kazakhstan. It is also the second-tallest freestanding structure of any type in Canada, behind the CN Tower but ahead of First Canadian Place. As of 2023, it is the 51st-tallest freestanding structure in the world. The Superstack is located on top of the largest nickel smelting operation in the world at Vale's Copper Cliff processing facility in the city of Greater Sudbury.

In 2018, Vale announced that the stack would be decommissioned and dismantled, beginning in 2020.[2] Two new, smaller stacks were constructed under the company's Clean Atmospheric Emissions Reduction Project.[3] In July 2020, Vale announced that the Superstack had been officially taken out of service, but would remain operational in standby mode for two more months as a backup in the event of a malfunction in the new system,[4] following which the dismantling of the Superstack would begin.[5] As of 2024, however, Vale has not yet announced the awarding of a demolition contract on the Superstack, and some have called for the stack to be left in place as a tourist attraction;[6] in September 2024, Vale announced an updated plan which will see the stack dismantled by 2029.[7]

In addition to further reducing sulphur dioxide emissions by 85 per cent, the decommissioning of the stack is expected to cut the complex's natural gas consumption in half.[4]