Brazil

Vermelhos Mine

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Overview

Mine TypeUnderground
StatusActive
Commodities
  • Copper
Mining Method
  • Sub-level open stoping (SLOS)
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SnapshotThe Vermelhos Underground Mine is part of the Caraíba Complex. Ore is transported from the Vermelhos UG Mine and the Surubim Mine to the Caraíba Mill complex via the Curaça Valley Haul Road, which passes adjacent to the Surubim Mine in the central portion of the Curaçá Valley, over a total transport distance of approximately 80 kilometers.
Related AssetCaraíba (MCSA) Operation

Owners

SourceSource
CompanyInterestOwnership
Ero Copper Corp. 99.6 % Indirect
Mineração Caraíba S.A. (operator) 100 % Direct
Ero Copper Corp. (“Ero Copper, “Ero” or the “Company”) is a Vancouver-based copper mining company whose primary asset is a 99.6% interest in Mineração Caraíba S.A. (“Mineração Caraíba” or “MCSA”), a Brazilian mining company operating in the Curaçá Valley, northeastern Bahia State, Brazil.

Within the mining concessions, MCSA holds 100% legal and beneficial ownership.

Contractors

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Deposit type

  • Magmatic
  • Vein / narrow vein
  • Breccia pipe / Stockwork

Summary:

The Vermelhos District is located 60 km north of the Caraíba Mine. In this district, copper mineralization has been identified over 4.5 km in a NNE direction including the Siriema deposit (N5), the Vermelhos Mine (N7), the N8, N9, and N10 deposits. The Vermelhos Mine area is largely covered by quartz-rich colluvium with rare outcrops occurring along drainages. The deposits are located within the gneiss of Tanque Novo Complex, comprising orthogneiss (enderbitic and tonalites gneiss with local garnet gneiss units) which have undergone granulite facies metamorphism and were cross-cut by mafic to ultramafic intrusions. The well-foliated enderbitic gneiss is characterized by plagioclase, quartz, microcline, orthopyroxene, and biotite with minor magnetite. The garnet gneiss is formed by plagioclase, quartz, phlogopite, and garnet and gneissic fabric is marked mostly by phlogopite and stretched plagioclase crystals. This unit is not magnetic. The mafic rocks are composed of the norites, gabbros, and gabbro-norites. The ultramafic rocks are the main ore host of the copper mineralization and are composed by pyroxenites, and melanorites. The gneiss and mafic-ultramafic rocks are cross-cut by late, steep westerly-dipping, N-S to NNE-SSW trending, granite and pegmatite dykes measuring a few centimeters up to 40m thick. The pegmatite dykes extend from the Siriema deposit to the N8 deposit. Minor late quartz veins and diabase dykes cross-cut all lithologies. The gneissic country rocks show a migmatitic texture with a fabric that is moderately northerly dipping (45° to 30º) grading to sub-horizontal gneissic banding. The mineralized mafic-ultramafic rock units in the Siriema, Vermelhos Mine and N8 are trending generally N-S to NNE-SSW and dip steeply to the west. However, in the high-grade Sombrero and the Toboggan zones of the Vermelhos UG Mine, the ultramafic units dip moderately to the East and the West respectively in a synform shape and contains generally higher grade and thicker copper mineralization, together with locally elevated Ni grades. In those zones, the ultramafic units are following the trend of the gneissic foliation and locally, the ultramafic units are injected at the contact between the enderbitic gneiss and the garnet gneiss. In addition to the shallow- to moderately dipping Sombrero and Toboggan there is another mineralized ultramafic unit that occupies the contact between the footwall garnet gneiss and the hanging wall enderbitic gneiss, making this lithological contact, in a hinge zone of a synform, a potential structural trap favoring the migration and deposition of the mafic-ultramaficrelated mineralization. A series of sub-vertical N-S, NW-SE and NE-SW faults and mylonitic shear zones occur in the Vermelhos district. These faults and shear zones may represent structures developed during the D3 deformation phase described by Frugis (2017) or later structures that locally displace the mineralization with minor movements. Similar alteration mineralogy to the Pilar UG Mine is present in the Vermelhos District and include potassic (phlogopite and K-feldspar), sodic (albite), carbonate (calcite), calcsilicate (diopside), serpentine, as well as silica and garnet. The alteration also variably obliterates and locally crosscuts the gneissic banding. An important silica alteration zone overprints the large pegmatite unit to the east of the mine and contains disseminated chalcopyrite. The main sulphides of the deposits in the Vermelhos District consist of chalcopyrite (approximately 70 to 75%), bornite (20 to 25%) and minor chalcocite. The chalcopyrite contains low concentration of nickel (Tappert, 2020). Copper sulphides are associated with minor pyrite, pyrrhotite, pentlandite as well as chromite and magnetite. Sulphide textures include interstitial, net-textured, stringer and sulphide-rich matrix breccias mostly concentrated in the mafic-ultramafic units but can also occur as veins and dissemination in the adjacent gneiss. Evidence throughout the Curaçá Valley of sulphide zonation, characterized as pyrrhotite +/- pentlandite zoning to pyrrhotite +/- pentlandite plus chalcopyrite and finally to chalcopyrite plus bornite is more common in the Vermelhos District, both within the Vermelhos UG Mine and at Siriema. High-grade mineralization in the Vermelhos District is often closely associated with phlogopite enrichment. The nickel, cobalt and PGE content tends to be higher in the Siriema deposit than in Vermelhos and the N8 and N9 deposits, but further analytical work is needed to confirm these observations. The detailed textures observed on polished slabs of sulphides show intergrowths of chalcopyrite, pentlandite, chromite, pyrrhotite and bornite. Oxidized mineralization occurs as malachite and chrysocolla within the weathered zone that occurs from 15 m to 40 m depth and, to date, is only associated with mafic-ultramafic rocks in the Vermelhos District.

Reserves

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Mining Methods

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Comminution

Crushers and Mills

Milling equipment has not been reported.

Processing

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Production

Combined production numbers are reported under Caraíba (MCSA) Operation

Operational metrics

Metrics202320202018
Tonnes processed  ....  Subscribe
Daily ore mining rate  ....  Subscribe  ....  Subscribe
Daily mining capacity  ....  Subscribe  ....  Subscribe2,500 t
Ore tonnes mined  ....  Subscribe  ....  Subscribe206,873 t
^ Guidance / Forecast.

Production Costs

Commodity production costs have not been reported.

Operating Costs

Currency20212020201920182017
UG mining costs ($/t mined) BRL 152.48  127.7  112.93  120.47  125  

Financials

Units20212020
Capital expenditures M USD  ....  Subscribe  ....  Subscribe

Heavy Mobile Equipment

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Personnel

Mine Management

Job TitleNameEmailProfileRef. Date
....................... Subscription required ....................... Subscription required ........... Subscription required Subscription required Jun 29, 2023
....................... Subscription required ....................... Subscription required ........... Subscription required Subscription required Jun 29, 2023
....................... Subscription required ....................... Subscription required ........... Subscription required Subscription required Jun 29, 2023

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