Mining Intelligence and News
Brazil

Sao Francisco Mine

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Categories

Overview

Mine TypeOpen Pit
StatusCare and Maintenance
Commodities
  • Gold
Mining Method
  • Truck & Shovel / Loader
Production Start... Lock
SnapshotThe São Francisco Gold Mine (“São Francisco”) – part of EPP Mines, an open-pit heap leach gold mine located in the southwest of the state of Mato Grosso, Brazil. Currently, the mine is in care and maintenance.

Owners

SourceSource
CompanyInterestOwnership
Aura Minerals Inc. 100 % Indirect
The Mine’s surface and mineral rights are owned by Mineração Apoena S.A. (“Apoena”), a beneficially-owned indirect subsidiary of Aura.

Deposit type

  • Vein / narrow vein
  • Breccia pipe / Stockwork

Summary:

The Sao Francisco Mine is a shear hosted lode gold deposit. It is epigenetic, structurally controlled, and composed of narrow, 1 to 5 cm wide, quartz veins containing free gold. The veins and vein systems and stockworks both parallel and crosscut the bedding planes and appear to represent separate but closely related ineralizing events.

The local rocks at the Sao Francisco Mine have been subjected to low-grade metamorphism. They consist of fine to coarsegrained meta-arenites (metamorphic sandstones), with locally reddish-coloured metapelites (metamorphic mudstones) and occasionally metaconglomerates (old pebble beds) of the Fortuna Formation, the basal unit of the Aguapeí Group. The metaconglomerates are composed of quartz pebbles and grains set in a siliceous sandy matrix. Primary sedimentary structures such as cross-bedding, graded bedding, and ripple marks are commonly observed.

Mineralization is enclosed by a hydrothermal alteration zone (“HAZ”). The HAZ occurs as a regular steeply dipping tabular zone; the depth of the HAZ has yet to be defined by drilling. Alteration associated with mineralization in the HAZ consists of silicification and occasional sericite and chlorite.

The gold occurs as free gold and frequently as coarse nuggets measuring several millimeters in diameter with the quartz, as laminations along the fracture planes, and within limonite boxwork after pyrite and arsenopyrite.

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

CommodityUnits201720162015
All production numbers are expressed as metal in doré.

Operational metrics

Metrics201720162015
Tonnes processed 302,669 t2,922,540 t3,944,557 t
Stripping / waste ratio 0.1 0.68
Ore tonnes mined 1,967,530 t4,098,327 t
Waste 202,164 t2,806,730 t
Total tonnes mined 2,169,694 t6,905,057 t

Production Costs

CommodityUnits2017
Cash costs Gold USD 971 / oz  

Heavy Mobile Equipment

Fleet data has not been reported.

Personnel

Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Jun 28, 2023

EmployeesContractorsTotal WorkforceYear
...... Subscription required ...... Subscription required ...... Subscription required 2016
...... Subscription required ...... Subscription required ...... Subscription required 2015

Aerial view:

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