Vale's Copper Cliffs smelter is "ramping down operations" for two weeks.
Starting Nov. 10, company spokesperson Danica Pagnutti said the smelter was placed in a 'hot standby state' to "optimize the concentrate stock levels" coming from its mines and mills.
The company didn't confirm if this decision is related to the status of new Totten Mine, west of Sudbury, which remains closed following a September incident and subsequent Ministry of Labour investigation where 39 miners had to be rescued from below ground after a scoop bucket equipment blocked the shaft, the main method of egress.
"Ramping down means the furnace will not be completely shut off," said Pagnutti by email.
There will no impact to the 400 employees working there. They'll continue to report to work for regular shifts and perform maintenance, the company said.
Vale said there will no impact to Vale customers as the Copper Cliff nickel refinery will continue to operate.
According to the company's website, the smelter makes a copper product that is sold to market and for various nickel streams shifted over the refinery nearby or over to Britain. The complex can produce up to 150,000 tonnes of a nickel and copper in matte products, a semi-finished product requiring further processing.