Brazil bans tailings dams after mine waste disaster
Brazil has banned the type of mining waste dam involved in two disasters, one of which was at a project jointly owned by BHP.
Brazil has banned the type of mining waste dam involved in the Brumadinho and Samarco disasters, forcing companies to close dozens of sites by 2021.
More than 300 people are feared dead after the collapse of an embankment holding back mining waste slurry known as “tailings” in a giant pond at Vale’s iron ore mine in Brumadinho, Minas Gerais province, last month.
The accident at Corrego do Feijao was an even more deadly repeat of the 2015 dam failure at Vale and BHP’s jointly-owned Samarco mine, at Mariana in Minas Gerais, that killed 19.
Both dams were built using the “upstream” system, the cheapest but generally regarded as the most risky method, as the dam wall is built up backwards into the pond on top of mining waste.
Brazil’s mining regulator said that it would prohibit the construction of any new “upstream” dams. It ordered companies to come up with plans for decommissioning by August and to ensure that they were executed by 2021.
About 50 such dams exist in Minas Gerais, according to Reuters. There is little reliable data on such facilities worldwide, although they are estimated to number in the thousands.
Vale, the world’s biggest iron ore miner, had already begun to decommission all 19 of its upstream dams after the Samarco disaster and had stopped adding more tailings to them.
It had been preparing to decommission Brumadinho and has said that it will expedite closure of its ten remaining sites, denting its output by about 10 per cent.
The Times