United States

Castle Mountain Phase 2 Expansion Project

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Overview

Mine TypeOpen Pit
StagePermitting
Commodities
  • Gold
Mining Method
  • Truck & Shovel / Loader
Production Start... Lock
Mine Life... Lock
ShapshotThe Castle Mountain Project is being developed in two stages, Phase 1, and Phase 2. The Phase 1 project, completed in 2020 and currently operating, consists of a double-lined run of mine (ROM) heap leach facility to treat 14,000 short tons of ore per day (ton/d). The Phase 2 project will consist of the expansion that is described within this project.

The Company expects to submit Phase 2 permit applications in Q1 2022.
Related AssetCastle Mountain

Owners

SourceSource
CompanyInterestOwnership
Equinox Gold  Corp. 100 % Indirect
Equinox, through its indirect wholly owned subsidiary NewCastle Gold Ltd., has 100% of the right, title, and beneficial interest in and to Castle Mountain Venture which owns the Castle Mountain Mine.

Contractors

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Deposit type

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

Summary:

Castle Mountain is classified as a low-sulfidation epithermal gold deposit (Scott et al., 2018), a sub-type of the epithermal class of gold and silver deposits (Sillitoe and Hedenquist, 2003). Epithermal gold-silver systems are driven by magmatic activity and form high-level vein, stockwork, disseminated and/or replacement deposits that may be mined by open-pit and/or underground methods. Some deposits also contain substantial resources of Ag, Pb, Zn, Cu and/or Hg.

Structure and associated rock porosity-permeability characteristics are the first-order control on the distribution of gold. Flow-dome breccia margins, phreatic diatremes, fault cataclasite and fractures focused provided conduits for hydrothermal fluids and contain the highest gold grades. Unfractured coherent flow-dome facies, clay altered volcaniclastic facies, and clay altered phreatomagmatic diatremes with low or variable permeability are weakly mineralized due to lower fluid interaction. Lower permeability units that are mineralized have been cut by structures such faults, fractures, or phreatic diatremes that promoted hydrothermal fluid interactions.

Gold is focused along structures and margins of facies contacts. It is believed that sub-vertical structures acted as pathways for magma and are responsible for the emplacement of the felsic volcanic package. These same structures also acted as conduits for gold-bearing hydrothermal fluids. Intersections of the steep structures with more permeable volcanic rocks created an environment for enhanced gold precipitation from hydrothermal fluids, possibly due to processes of boiling and interaction with meteoric water.

Lithologic controls are dependent on the host rock texture. Tuff beds, auto-breccias, and hydrothermal breccias have permeable fragmental textures. Brittle rhyolite flows and intrusive equivalent rocks exhibit intense fracturing and are characterized by cooling joints, vesicular zones, spherulitic vugs, and flow foliations. Gold occurs within secondary silica in all these features. Major fault and fracture systems and intersections of fracture systems provided structural controls for mineralization. In the deposit area, north-northeast-striking, mineralized fracture zones are exposed in outcrop.

The morphology of mineralization follows two patterns. Firstly, gold is enriched along steep to vertical brecciated contacts of flow-domes and phreatomagmatic diatremes. Secondly, gold occurs in broad tabular zones that correlates with the general orientation bedding. The lateral extent of the mineralized bodies centered around fault zones are dictated by the intensity and extent of fracturing and faulting, in addition to the paleo-porosity of the host rocks.

Some faults and fracture zones are not gold-bearing since the structural regimes through the Project were active both pre- and post-mineralization. Gold seems to have precipitated during a single phase within a larger and longer-lived structural and hydrothermal event.

Silicification is commonly associated with gold occurring as pervasive silica flooding and quartz veining. Quartz veins can be vitric and “gel-like” or opaque white-gray opal. Vitric quartz veins typically occur in clusters as sheeted veins or stockwork in zones ranging from 3 to 35 ft (1 to 10 m) wide. Amorphous quartz occurs as discontinuous irregular veins and as open space filling quartz. The strongest silica alteration associated with gold is found along brecciated coherent rhyolite margins; this results in mosaic breccias where angular rhyolite clasts are within a hydrothermal-related silica matrix.

Gold on the Project occurs in oxidized fractures, faults, discontinuous veins, and breccia matrix. Gold mineralization correlates best with the deep red, red-brown and brown iron oxide that can range in color from pink to red-brown. The iron oxide intensity and appearance are commonly controlled by the volcanic facies occurring as discontinuous, fracture-controlled textures in coherent rhyolite facies, as matrix replacement in rhyolite breccias, wispy selvages and clast haloes in volcaniclastic rocks, and pervasive or matrix selective in diatremes. These iron oxide textures can be cut by fracture and vein filling iron oxide that ranges in color from brown-tan to red.

Visible gold is rarely observed in hand specimen and core. In petrographic samples collected near JSLA, visible gold is associated with iron oxide and silica and proximal to illite and adularia alteration (Cline, 2016). Gold deportment studies from Oro Belle by Chudy and Lane (2020) indicate that mineralization is roughly 79% native gold, 17% electrum and 4% silver minerals by frequency of grain count. Quartz may be intergrown with iron oxides/hydroxides, most commonly as hematite, which have formed as oxidation products of former sulfide minerals. There is a low abundance of sulfides observed on the Project. The most common sulfide mineral is pyrite, and varies from nil to 1%, which occurs within clasts and matrix.

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

CommodityProductUnitsAvg. AnnualLOM
Gold Payable metal koz 3,187
Gold Metal in doré koz 2223,203

Operational metrics

Metrics
Daily ore mining rate  ....  Subscribe
Daily processing rate  ....  Subscribe
Annual processing rate  ....  Subscribe
Stripping / waste ratio  ....  Subscribe
Waste tonnes, LOM  ....  Subscribe
Ore tonnes mined, LOM  ....  Subscribe
Total tonnes mined, LOM  ....  Subscribe
Tonnes processed, LOM  ....  Subscribe
* According to 2021 study.

Production Costs

CommodityUnitsAverage
Cash costs Gold USD  ....  Subscribe
Total cash costs Gold USD  ....  Subscribe
All-in sustaining costs (AISC) Gold USD  ....  Subscribe
Assumed price Gold USD  ....  Subscribe
* According to 2021 study / presentation.

Operating Costs

Currency2021
OP mining costs ($/t mined) USD 1.59 *  
OP mining costs ($/t milled) USD  ....  Subscribe
Processing costs ($/t milled) USD  ....  Subscribe
G&A ($/t milled) USD  ....  Subscribe
Total operating costs ($/t milled) USD  ....  Subscribe
* According to 2021 study.

Project Costs

MetricsUnitsLOM Total
Initial CapEx $M USD  ......  Subscribe
Equipment leasing costs $M USD  ......  Subscribe
Working capital $M USD  ......  Subscribe
Sustaining CapEx $M USD  ......  Subscribe
Closure costs $M USD  ......  Subscribe
Total CapEx $M USD  ......  Subscribe
OP OpEx $M USD  ......  Subscribe
Processing OpEx $M USD 620
Refining costs $M USD  ......  Subscribe
Transportation (haulage) costs $M USD 3
G&A costs $M USD 164
Total OpEx $M USD  ......  Subscribe
Total Taxes $M USD  ......  Subscribe
Royalty payments $M USD  ......  Subscribe
Gross revenue (LOM) $M USD  ......  Subscribe
Net revenue (LOM) $M USD  ......  Subscribe
Operating margin (LOM) $M USD  ......  Subscribe
Net Income (LOM) $M USD  ......  Subscribe
Pre-tax Cash Flow (LOM) $M USD  ......  Subscribe
After-tax Cash Flow (LOM) $M USD  ......  Subscribe
Pre-tax NPV @ 5% $M USD  ......  Subscribe
After-tax NPV @ 5% $M USD  ......  Subscribe
Pre-tax IRR, %  ......  Subscribe
After-tax IRR, %  ......  Subscribe
Pre-tax payback period, years  ......  Subscribe
After-tax payback period, years  ......  Subscribe

Heavy Mobile Equipment

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Personnel

Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Feb 26, 2021
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Total WorkforceYear
...... Subscription required 2021

Aerial view:

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