Editing Inco Superstack (section)

{{short description|Second-tallest freestanding chimney}}
{{Use mdy dates|date=June 2020}}
{{Use Canadian English|date=October 2024}}
{{Infobox building
| name                = Inco Superstack
| image               = Inco Superstack.JPG
| image_size          = 250px
| image_alt           = <!-- or | alt = -->
| image_caption       = The Vale-Inco (former Inco) Superstack at the Inco Copper Cliff smelter
| map_type            =
| map_alt             =
| map_caption         =
| map_size            =
| map_dot_label       =
| map_dot_mark        =
| relief              =
| alternate_names     = Vale Superstack
| status              =
| cancelled           =
| topped_out          =
| building_type       = Chimney
| location            =
| address             =
| location_city       = [[Greater Sudbury]]
| location_country    = Canada
| coordinates         = {{coord|46|28|48.23|N|81|3|23.43|W|display=inline,title}}
| altitude            =
| current_tenants     =
| namesake            =
| groundbreaking_date =
| start_date          = 1970
| stop_date           =
| est_completion      =
| topped_out_date     =
| completion_date     = 1972
| opened_date         =
| renovation_date     =
| closing_date        =
| demolition_date     = <!-- or | destruction_date    = -->
| cost                = $25 million ($160 million inflation adjusted)
| ren_cost            =
| owner               = [[Vale Limited]]
| height              = {{convert|381|m|ft|abbr=on}}
| diameter            = at base: {{convert|35|m|ft|abbr=on}}<br/>at top: {{convert|16|m|ft|abbr=on}}
| circumference       =
| weight              =
| other_dimensions    =
| structural_system   =
| material            = Reinforced concrete with stainless steel liner
| size                =
| architect           =
| architecture_firm   =
| developer           =
| engineer            =
| structural_engineer =
| main_contractor     =
| designations        =
| known_for           =
| website             = <!-- {{URL|example.com}} -->
| references          = <ref name=facts/>
| footnotes           =
| highest_prev        = [[Mitchell Power Plant]]
| highest_next        = [[Ekibastuz GRES-2 Power Station]]
| highest_start       = 1971
| highest_end         = 1987
| highest_region      = the world
| highest_reflabel    =
}}

The '''Inco Superstack''' in [[Greater Sudbury|Sudbury]], [[Ontario]], with a height of {{convert|381|m|ft}}, is the tallest [[chimney]] in [[Canada]] and in the [[Western Hemisphere]] and the [[List of chimneys|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 [[List of tallest freestanding structures in the world|51st-tallest freestanding structure]] in the world. The Superstack is located on top of the largest nickel [[smelting]] operation in the world at [[Vale Limited|Vale]]'s [[Copper Cliff, Ontario|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.<ref>[https://www.cbc.ca/news/canada/sudbury/superstack-demolition-begins-1.4829643 "Superstack dismantling will begin in 2020, Vale says"]. [[CBCS-FM|CBC Northern Ontario]], September 19, 2018.</ref> Two new, smaller stacks were constructed under the company's Clean Atmospheric Emissions Reduction Project.<ref>Molly Frommer, [https://northernontario.ctvnews.ca/two-new-smaller-stacks-are-ready-decommissioning-of-sudbury-s-superstack-about-to-begin-1.5100192 "Two new smaller stacks are ready, decommissioning of Sudbury's Superstack about to begin"]. [[CTV Northern Ontario]], September 10, 2020.</ref> 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,<ref name=operational>[https://www.northernontariobusiness.com/regional-news/sudbury/sudburys-iconic-superstack-operational-no-more-2597116 "Sudbury's iconic Superstack operational no more"]. ''[[Northern Ontario Business]]'', July 28, 2020.</ref> and the dismantling of the Superstack would then begin.<ref>Lindsay Kelly, [https://www.northernontariobusiness.com/regional-news/sudbury/slow-process-of-demolition-to-start-on-vales-superstack-2598483 "Slow process of demolition to start on Vale's Superstack"]. ''[[Northern Ontario Business]]'', July 29, 2020.</ref> Although some have called for the stack to be left in place as a tourist attraction,<ref>Judith Van Boxel, [https://www.thesudburystar.com/opinion/columnists/column-why-tear-down-the-superstack-turn-it-into-a-tourist-attraction "Column: Why tear down the Superstack? Turn it into a tourist attraction"]. ''[[Sudbury Star]]'', May 17, 2023.</ref> in September 2024, Vale announced an updated plan, which will see the stack dismantled by 2029.<ref>[https://www.northernontariobusiness.com/industry-news/mining/sudburys-superstack-slated-for-demolition-by-2029-9474247 "Sudbury's Superstack slated for demolition by 2029"]. ''[[Northern Ontario Business]]'', September 4, 2024.</ref>

In addition to further reducing [[sulphur dioxide]] emissions by 85 per cent, the decommissioning of the stack was expected to cut the complex's [[natural gas]] consumption in half.<ref name=operational/>