Vale and the United Steelworkers Local 6500 will conduct a joint investigation into the death of industrial mechanic Paul Rochette, who died at the Copper Cliff smelter on April 6.

Paul Rochette, 36, died of severe head trauma. His 28-year-old co-worker was also injured and remains in hospital with a concussion, the mining company stated earlier.

In a press release issued Friday, Vale said the scene of the fatal incident remains off-limits as the Ministry of Labour continues its investigation. Moving forward, the company said it will work closely with the union to understand what happened.

United Steelworkers Local 6500 hundred president Rick Bertrand said the company has been sharing information and co-operating.

"We've had many good conversations with the company in the last few days," he said.

"We're able to access the documents, and records and interviews with staff and employees and get the information that's needed."

Most investigations are conducted jointly, Bertrand added.

"We've always done it in the past. And you know, the last fatality, the fatality that happened at Stobie mine, [a joint investigation] didn't happen and ... it's great that this time we were able to work together and share the information and work together​."

Bertrand said the investigation could take anywhere from one to three months and will yield a report and recommendations.

In the meantime, the company said smelter furnaces were expected to ramp up over the weekend. Vale said that process takes time and it's expected that processing will be back up by the middle of next week.