Overview
| Status | Care and Maintenance |
| Mine Type | Open Pit |
| Commodities |
|
| Mining Method |
|
| Production Start | ...  |
The 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.
In Sao Francisco, Aura is evaluating the potential to restart the mine. |
Source:
p. 15
The Mine’s surface and mineral rights are owned by Mineração Apoena S.A. (“Apoena”), a beneficially-owned indirect subsidiary of Aura.
Contractors
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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.
Summary:
Mining at the Sao Francisco Mine is carried out by contractors using a combination of hydraulic excavators, front end loaders, and 35 t haulage trucks with typical pit support equipment to sustain the operation. The pit is accessed via a standard access road or ramp 15 m wide at a minus 10% grade which provides access to the benches. Benches are 10 m high, with alternating 4.3 and 10 m wide safety berms.
Production drilling is carried out with 5.5 inch diameter holes and patterns for waste and ore of 6 x 4 m and 3.5 x 4.5 m, respectively. Standard bench height is 10 m, with one meter of sub-grade drilling for floor control.
Source:
- subscription is required.
Flow Sheet:
Summary:
- subscription is required.
Production:
| Commodity | Units | 2017 | 2016 | 2015 | 2014 |
|
Gold
|
oz
| 8,739 | 44,433 | 59,461 | 84,959 |
All production numbers are expressed as metal in doré.
Operational Metrics:
| Metrics | 2017 | 2016 | 2015 | 2014 |
|
Tonnes processed
| 302,669 t | 2,922,540 t | 3,944,557 t | 4,250,691 t |
|
Total tonnes mined
| | 2,169,694 t | 6,905,057 t | 9,027,336 t |
|
Ore tonnes mined
| | 1,967,530 t | 4,098,327 t | 3,835,332 t |
|
Waste
| | 202,164 t | 2,806,730 t | 5,192,004 t |
|
Stripping / waste ratio
| | 0.1 | 0.68 | 1.35 |
Reserves at December 31, 2016:
| Category | Tonnage | Commodity | Grade | Contained Metal |
|
Proven
|
11,600 kt
|
Gold
|
0.45 g/t
|
197 koz
|
|
Probable
|
41,400 kt
|
Gold
|
0.76 g/t
|
1,010 koz
|
|
Proven & Probable
|
53,000 kt
|
Gold
|
0.69 g/t
|
1,177 koz
|
|
Measured
|
525,770 kt
|
Gold
|
0.78 g/t
|
13,140 koz
|
|
Indicated
|
352,240 kt
|
Gold
|
0.84 g/t
|
9,513 koz
|
|
Measured & Indicated
|
878,000 kt
|
Gold
|
0.8 g/t
|
22,650 koz
|
|
Inferred
|
119,100 kt
|
Gold
|
0.68 g/t
|
2,620 koz
|
Commodity Production Costs:
| | Commodity | Units | 2017 | 2016 | 2015 |
|
Cash costs
|
Gold
|
USD
|
971 / oz
|
892 / oz
|
979 / oz
|
Financials:
| | Units | 2016 |
|
Capital expenditures
|
M USD
|
0.2
|
|
Revenue
|
M USD
|
56.7
|
Corporate Filings & Presentations:
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