He said the incident was not affecting the flow of supplies to the Friguia plant, which produces some 630,000 tons of alumina per year, and denied the plant had been shut.
"We affirm that the rail incident does not affect supply of primary materials to the Friguia refinery, and has no effect on the output volumes," Yuriy Grigoryev said in an email.
"Currently, the Friguia refinery is operating normally."
A union official at the Friguia plant, Kabinet Barry, said RUSAL had decided to shut the refinery, in part to pressure workers negotiating for higher pay.
"We were in negotiations when the RUSAL management told us that they decided to stop production," Barry said.
Grigoryev said that information "does not correspond with reality", but gave no further details.
Other workers at the refinery, asking not to be identified, also told Reuters the plant was shut but said they were not sure why.
Russia's RUSAL, the world's top aluminium producer, has a long history of troubled labour relations at the Friguia plant, with strikes over pay occasionally halting output.
The refinery brings in supplies such as fuel and caustic soda along the rail line from the port of Conakry, and moves finished alumina to port the same way.
Witnesses said the train derailed near Conakry and appeared to halt all movement along the tracks. (Reuters)
