Ontario's government laid charges in March 2015, and Vale pled guilty in a Sudbury court on Monday, the company said. On top of the fine, it will pay a 25 percent surcharge into a fund for victims of crime.

The incident at Vale's Copper Cliff smelter killed Paul Rochette and left another worker seriously injured.

"There is nothing more important to us than the safety of our people, and the loss of one of our employees is devastating," Stuart Harshaw, vice president of Vale's Ontario operations, said in a statement.

It is the second large fine paid by the company in Ontario since 2013. In September of that year, the company pled guilty to violating the workplace safety law after two workers, Jason Chenier and Jordan Fram, were crushed to death by muck, sand and water at the company's Stobie Mine, also in Sudbury.

In that case Vale paid a C$1.05 million fine plus a 25 percent surcharge, which at the time was the largest workplace safety fine ever imposed by an Ontario court.

A shift supervisor also pled guilty to one charge in connection with the 2014 smelter incident and will pay a C$3,000 fine, the company said.

Vale said it has addressed 58 recommendations that came out of a joint investigation with the union that represents workers at the site.

($1 = 1.3353 Canadian dollars)

(Reporting by Allison Martell; Editing by Paul Simao)