Brazil

Barro Alto Mine

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Categories

Overview

Mine TypeOpen Pit
StatusActive
Commodities
  • Nickel
Mining Method
  • Truck & Shovel / Loader
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Mine Life... Lock
SnapshotBarro Alto facility - world class ferronickel producer.

The Barro Alto Industrial Complex includes six mining areas and an industrial processing plant.

The Barro Alto mine currently operates four open pits: Area 1, Area 2, Area 3, and Area 4. Area 5 became operational in November 2021, in 2022 it was not operational. Additionally, studies to support the licensing request for a sixth pit (Area 6) are underway. Area 6 would provide an additional slag deposit with additional slag production. This area is anticipated to enter production as other areas are exhausted, therefore no increase in overall production is anticipated by the mine.

Owners

SourceSource
CompanyInterestOwnership
Anglo American plc. 100 % Indirect
Barro Alto is 100% owned by Anglo American.

Deposit type

  • Saprolite
  • Laterite

Summary:

The Barro Alto mineral resource is primarily saprolite overlain by laterites and extends for 35 km in an arc from southwest to northeast. The deposit is in the Barro Alto mafic-ultramafic complex, which is part of the Pre-Cambrian shield in the state of Goiás. The complex is composed of a sequence of serpentinised dunites and pyroxenites, enveloped by gabbros.

The Barro Alto deposit occurs in a curved strip within the ultramafic zone of the Barro Alto Complex. Valleys and fault zones allow for the division of the deposit into seven separate areas. The relative concentration of iron and nickel occurring at the top of the profile (limonite zone typical of oxidised deposits), is the result of leaching and intense tropical weathering of the ultramafic lithologies. In more developed areas, the nickel is leached downwards, where it concentrates in the lower saprolite zone, forming areas rich in garnierite (silicified deposits).

The nickel deposits of the Barro Alto have the shape of a bow with concavity to NW. Presents approximately 156 km in length, with a width of 8 km (North) up to 25 km (central region).

The mineralisation corresponds to the surficial weathered portions of the serpentinites. There are three types of saprolitic ore. The West type ore tends to have higher nickel grades and silica/magnesia ratios than the East type and Plain type ores.

The Barro Alto complex is bounded by metamorphic volcanic-sedimentary sequences (Ferreirafilho et al., 1992) and is a major mafic-ultramafic layered intrusion that was subjected to granulite facies metamorphism. It is composed mainly of gabbronorite, with minor dunite, peridotite, norite, gabbro, anorthosite and banded clinopyroxene-garnet amphibolite (Moraes and Fuck, 2000). In the complexes of Niquelandia and Barro Alto, lateritic weathering has formed important reserves of extractable Ni ore, representing around 2 million tons of metallic Ni (Raous et al., 2010). Ultramafic areas are characterized by a natural enrichment in heavy metals. In the case of the Barro Alto complex, this enrichment is mainly in Ni, however the Cr content has been reported as high as 6030 mg kg-1 (Ratié et al., 2015) and 46800 mg kg-1 (Raous et al., 2010), which is not high enough to be extracted, but potentially harmful for the environment. Mineral phases containing Cr include Cr-rich magnetite (Fe2+(Fe3+,Cr)2O4), chromite (FeCr2O4), talc (Mg3Si4O10(OH)2) chlorite ((Mg, Fe)5 Al[(OH)8 AlSi3O10]) and spinels (Oze et al., 2004).

Reserves

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Mining Methods

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Comminution

Crushers and Mills

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Processing

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Production

CommodityUnits202320222021202020192018201720162015
Nickel t  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe33,90033,50034,90035,50021,300
All production numbers are expressed as metal in alloy.

Operational metrics

Metrics202320222021202020192018201720162015
Ore tonnes mined  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe4,075,600 t4,667,200 t6,272,800 t2,630,700 t2,943,600 t
Tonnes processed  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe2,265,700 t2,264,200 t2,309,300 t2,357,100 t1,472,800 t
Annual production capacity  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe36,000 t of nickel metal in alloy

Production Costs

Commodity production costs have not been reported.

Heavy Mobile Equipment

Fleet data has not been reported.

Personnel

Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Mar 5, 2024
....................... Subscription required ....................... Subscription required Subscription required Mar 4, 2024
....................... Subscription required ....................... Subscription required Subscription required Mar 4, 2024
....................... Subscription required ....................... Subscription required Subscription required Mar 4, 2024
....................... Subscription required ....................... Subscription required Subscription required Mar 4, 2024
....................... Subscription required ....................... Subscription required Subscription required Mar 4, 2024

EmployeesContractorsTotal WorkforceYear
...... Subscription required ...... Subscription required ...... Subscription required 2022
...... Subscription required ...... Subscription required ...... Subscription required 2012

Aerial view:

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