Vale ordered to shut 25 iron ore tailings dams in Brazil

Sao Paulo — Brazil's National Mining Agency has ordered the immediate closure of 47 iron ore tailings dams for which stability was not certified, with more than half of them owned by iron ore giant Vale and its affiliates.

According to the agency, of the 431 tailings dams currently included in the National Dam Safety Policy, certifications for stability were forwarded for 384, declarations not attesting to stability were submitted for 31 and no documentation was sent in for 16, "which presupposes they do not have stability of the certified structure."

The list by the National Mining Agency, or ANM, also included the tailings dam of ArcelorMittal Mineração Serra Azul and the B2 Auxiliar dam, of Nacional Minérios, or Namisa, which belongs to the group Companhia Siderúrgica Nacional.

ANM added that Vale's Norte/Laranjeiras dam, at the company's largest iron ore mine in Minas Gerais (Brucutu), also failed to show stability.

Vale said Wednesday that 78 of its structures successfully registered stability declarations, while eight new structures had negative stability declarations and will be classified as emergency level 1.

The safety of Vale's facilities has been under huge inspection after two of its dams in Minas Gerais collapsed in less than four years.

The Brumadinho incident claimed the lives of about 270 people in January last year, while a similar incident at its joint-venture Samarco in 2015 killed 19 people, unleashing a mixture of mud and tailings into the state's rivers and waterways. Moreover, Vale earlier in the week told the Brazilian securities exchange commission that three of its dams were at higher risk of collapsing.

Dams in Brazil are labelled at risk levels, ranging from 1 to 3, in which level 3 indicates a structure is likely to collapse.

Vale said the dams to raise their risk level to 2 from 1 included the B3/B4 dam at its Mar Azul mine, the Doutor dam at its Timbopeba mine, as well as its Sul Inferior dam at its Gongo Soco mine. The risk level increased during the time period of September 2019 to March 2020, Vale said.

Potential for lower iron ore output in 2020

According to Vale, the Brucutu plant, which formerly disposed of tailings in the Norte/Laranjeiras dam (at emergency level 1 since December 2, 2019), will continue to operate at around 40% of its capacity through wet processing and tailings filtration.

The miner said that short-term alternatives for tailings disposal, such as the optimized use of the Sul dam, are being tested by geotechnical and operational teams and may increase Brucutu plant's processing capacity to 80%.

"If such alternatives for tailings disposal or the reclassification of the emergency level for Norte/Laranjeiras dam are not accomplished by the end of Q2 2020, there will likely be an impact on the 2020 annual iron ore fines production volume," Vale added.

Vale's full-year projection for iron ore production and sales volume was 340 million-355 million mt, based on a December presentation.