Page 92 - Annual Report 2020

1.9.3 Minerals Americas continued

Minas Gerais,
Espírito Santo
Brazil

Gov. Valadares

Belo Horizonte
(Main O ices) Nova Era – Antônio Dias
(Guilman-Amorim Hydroelectric Plant)
Vitória
Mining Lease (Sales O ice)
Mariana – Ouro Preto Muniz Freire
(Germano (Muniz Freire
Operational Unit) Hydroelectric Plant)
Anchieta
(Operational
unit and Ocean
Terminal at
Ponta Ubu)
Juiz de Fora
Samarco 1st pipeline
2nd pipeline 3rd pipeline
s1008_v1
Iron ore

Samarco (Brazil)
BHP Billiton Brasil Ltda (BHP Brasil) and Vale S.A. (Vale) each have Following Vale’s Brumadinho dam tragedy on 25 January 2019,
a 50 per cent shareholding in Samarco Mineração S.A. (Samarco), Brazil’s National Mining Agency (ANM) announced a requirement
the owner of the Samarco iron ore mine in Brazil. for all upstream construction tailings dams to be decommissioned
Overview by various dates, depending on their size. As required under the
regulatory requirements, a dam decommissioning conceptual
As a result of the tragic failure of the Fundão dam at Samarco design was filed with the ANM in August 2019 and a basic design
in November 2015, operations at Samarco remain suspended. was filed with the ANM in December 2019. Field works started in
Samarco comprises a mine and three concentrators located in the April 2020 for the program, which includes the decommissioning
state of Minas Gerais and four pellet plants and a port located in of the Germano pit dam and Germano main dam (including the
Anchieta in the state of Espírito Santo. Three 400-kilometre main dam and the Sela, Tulipa and Selinha saddle dykes) to
pipelines connect the mine site to the pelletising facilities. guarantee the long-term stability of the structures, as well
as final regrading of the impoundment area and, finally,
All geotechnical structures within the Germano facilities, including environmental rehabilitation.
tailings dams, are monitored 24 hours a day by Samarco, using
more than 800 pieces of monitoring and safety equipment, Construction of a new retaining dam, following the failure of the
including cameras, weather forecast stations, drones and Fundão dam, is now complete and was the last structure to be
accelerometers. In addition, sirens are installed along the river up built in the Fundão valley to ensure the remaining tailings would
to 80 kilometres downstream of Samarco. Geotechnical engineers not be remobilised. Further work relating to the starting dyke for
and technicians monitor data from the instrumentation in an the future tailings and waste piles is now incorporated into the
integrated monitoring control room, undertake daily field Germano decommissioning program. This work will be completed
inspections and perform monthly third party audits. by Samarco following transfer of the program from Fundação
Key developments during FY2020 Renova in September 2019.
Samarco operations restart consists of three main pillars: Alegria Looking ahead
Sul pit tailings disposal system, LOC (corrective operational The Samarco business plan considers an operations restart with
licence) issuance and filtration plant construction together with one concentrator and tailings filtering, which changes the tailings
operations readiness activities. Alegria Sul pit tailings disposal disposal from the use of tailings dams to disposal of the coarse
system implementation was completed in September 2019. portion of the tailings in dry stack piles and the disposal of slimes
The LOC was issued on 25 October 2019. US$44 million for BHP in a previously mined out pit. Samarco is focused on completing
Billiton Brasil Ltda’s share was approved to fund the restart of the filtration plant construction for dry stacking and completing
production at Samarco from a single concentrator in the second operational readiness activities. All filters are now installed and the
half of CY2020 or early CY2021 (BHP mid-view is January 2021). electrical and mechanical installation services are progressing.
The funds will be used for the first phase of installation of tailings As part of the dam decommissioning process, the Germano pit
filtration infrastructure and operational readiness activities. Work dam gallery plugging and the Germano main dam preliminary
related to the construction of the filtration plant and operations services have started. Samarco is looking ahead to complete
readiness activities have been slowed as a result of a reduced Germano main dam toe ground replacement, initial regrading
workforce as part of our COVID-19 response without a significant and initial excavation of the spillway in FY2021.
impact on the restart schedule.
BHP Brasil and Vale approved the filtration plant and operational
readiness activities investment in November 2019 and dam
decommissioning program investment for CY2020–2021 was
approved in April 2020.

90 BHP Annual Report 2020