A BHP company in Brazil will restart mining, five years after a dam collapsed and killed 19 people in the country’s biggest environmental disaster.

BHP on Thursday said the Samarco joint venture had started producing iron ore pellets at complexes in Minas Gerais and Espirito Santo after authorities approved the restart.

In 2015, a Samarco dam used to store mining waste collapsed and killed workers. It also sent roughly 40 million cubic metres of sludge into communities, the Rio Doce river and Atlantic Ocean.

BHP and Brazilian miner Vale have 50 per cent stakes in Samarco.

Shares were up 1.28 per cent to $42.99 at 1133 AEDT.