Overview
Stage | Production |
Mine Type | Underground |
Commodities |
|
Mining Method |
- Mechanized Cut & Fill
- Overhand Cut & Fill
- Longhole stoping
- Hydraulic backfill
|
Processing |
- Gravity separation
- Concentrate leach
- Agitated tank (VAT) leaching
- Carbon in pulp (CIP)
- Elution
- Carbon adsorption-desorption-recovery (ADR)
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
|
Mine Life | 12.3 years (as of Jan 1, 2019) |
December 30, 2020 - With the commencement of production at the PureGold Mine, activities at site are now concentrated on optimizing the operation, with Commercial Production anticipated by the end of Q1 2021.
Substantial infrastructure is in place, including a mill and tailings facility, grid power and paved highway access, a 1,275 metre deep shaft and headframe, 27 levels of underground workings, a portal and ramp, and substantial permits. |
Latest News | Pure Gold Mining Inc.: First Gold Poured at the PureGold Mine December 30, 2020 |
Source:
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Pure Gold is the 100% owner of the Madsen Gold Project (now PureGold) in the Red Lake Mining District.
Deposit Type
- Vein / narrow vein
- Orogenic
Summary:
The Madsen Gold Project is focused on identifying and delineating Archean orogenic gold deposits (Groves et al., 1998).
High grade mineralization at the Madsen deposit occurs in four identified zones: McVeigh, Austin, South Austin (including the A3 domain), and 8 Zone . Within each zone there are multiple parallel veins hosted within a highly altered and weakly mineralized corridor. In the McVeigh, Austin, and South Austin, the veins trend in the NW-SW dipping between 90° to 60° and are generally between 2 m to 10 m thick. In the 8 Zone, the modelled veins dip at around 40° with a lower grade perpendicular structure intersecting the main mineralized zone. The thickness of the veins in the 8 Zone range between 2 m to 8 m true width.
Madsen Deposit – Austin, South Austin (including A3 Domain) and McVeigh Zones
Most historical gold production and most of the current reserves and resources at the Madsen deposit are within the Austin, South Austin, and McVeigh zones which, along with the 8 Zone, comprise the Madsen deposit. At the property-scale, these zones all lie within much broader, kilometre-scale planar zones that are considered early (D1) shear or fault zones. The distribution of gold within these planar structures is controlled principally by the intersection of the structures with basalt/ultramafic lithological contacts.
The Austin and South Austin Zones are open down plunge from the reserves. Historical drilling intersected 14.3 g/t Au over 2.0 m in 2011 at 825 metres below past mining in the Austin Zone and drilling in 2017 returned 34.6 g/t Au over 4.3 m at 240 m below past mining in the South Austin Zone. Core review and geological modelling has confirmed alteration and host rock continuity at these depths.
Madsen Deposit: 8 Zone
The geology and mineralization style at the 8 Zone is somewhat distinct from that of other known zones within the Madsen deposit. Gold at the 8 Zone occurs within strongly altered and veined peridotite of the Russet Lake Ultramafic. By contrast, most gold at McVeigh, Austin and South Austin Zones is hosted within mafic host rocks proximal to generally barren ultramafic units. The 8 Zone has a planar geometry, strikes generally north-south and dips to the east at approximately 45° which is significantly shallower than the other zones. As it is presently modelled, the 8 Zone is approximately 130 m along strike by 700 m down dip and by 30 m in thickness.
Russet South Deposit
Gold at the Russet South deposit is hosted within folded and/or boudinaged blue-grey quartz veins that are similar to those characteristic of the 8 Zone. At Russet South, the veins mostly occur within weakly deformed 10 m-scale wide, planar zones proximal to the northern contact of Russet Lake ultramafic volcanic rocks and on both the hangingwall and footwall of a smaller ultramafic sill parallel to this contact. The veins are most commonly hosted within relatively weakly biotite- amphibole altered basalt, though some occur within ultramafic rock and underlying iron formations. Despite the complicated arrangement of individual veins, due to their transposed nature, zones of high vein density, deformation, alteration and gold mineralization can be defined over hundreds of metres of strike length, trending broadly sub- parallel or at low angle to stratigraphy which is itself broadly folded about south-plunging D2 folds in the Russet Lake area. Projected to surface, these zones of high vein density extend over a footprint of approximately 650 m by 650 m, and have been defined to a vertical depth of 200 m.
Wedge Deposit: 86, DV, CK, MJ and OL Zones
The Wedge deposit comprises three resource zones (DV, CK and MJ) and two mineralized zones (86 and OL) that remain at the exploration target stage.
The DV and CK Zones lie within the same structure that hosts the Fork Main Zone, but about 900 m along strike to the southwest. The intervening area is prospective for resource expansion and this area includes the 86 Zone exploration target.
Drilling directly underneath this surface mineralization in 2017 returned multiple intercepts exceeding 5 g/t Au (up to 22.9 g/t Au over 1.1 m). Gold is hosted in quartz veins spatially associated with both iron formation and altered basalt.
In detail, the DV and CK Zones comprise a series of up to three, concordant resource shapes across a collective width of 70 m and a maximum strike length of 700 m. At the DV Zone, gold is hosted within discontinuous quartz ± chlorite-amphibole veins (VBGQ veins) with biotite-amphibole-diopside selvages and minor pyrite, pyrrhotite, chalcopyrite and arsenopyrite (Branson, 2019b). At the CK Zone, the geology and mineralization are comparable to the DV Zone, though the host basalt rocks have been cut by quartz porphyry.
Fork Deposit and Fork Footwall Target
The Fork deposit lies within two concordant D1 shear zones spaced 100--150 m apart. These structures strike north-north-easterly and dip about -60°. The upper lens is known as the Main Zone. This lens occurs along a D1 shear zone that is continuous to the southwest with the shear zone that hosts the DV and CK Zones. The distribution of gold within this shear zone seems to be variously controlled by interaction with thin (~10 m to 20 m wide) ultramafic sills and iron formation in an otherwise basaltic host rock.
The lower lens has been referred to as the Fork Footwall Zone and it occurs within the Russet Lake Shear Zone (Baker, 2017). Here the Russet Lake Shear Zone is wholly within ultramafic volcanic rocks of the Russet Lake Ultramafic so controls on gold deposition are unclear since the host rock is generally homogenous. Potentially significantly, the Fork Footwall Zone occurs within the same shear zone that hosts the 8 Zone which occurs about 1.8 km downplunge to the northeast.
A third resource domain (North-south Domain) has been modeled between the Fork Footwall Zone and Fork Main Zone. It is not clear geologically how this relates to the modeled structures but perhaps it is a short lower-order splay.
Starratt
Gold mineralization at the Starratt target is very similar to that at the Madsen Mine. Gold occurs in similar strongly altered and deformed basalt (SAFZ) with the typical biotite-amphibole-diopside assemblage with local silicification and potassium feldspar alteration. The structural setting is also equivalent to Madsen whereby mineralized zones occur in planar bodies that cut at low oblique angles across the same ultramafic sills that occur at Madsen. As at Madsen, plunge control of mineralization at Starratt is controlled by the intersection of ultramafic units and these interpreted early structures but at Starratt the plunge is steeper owing to the general steepening of the stratigraphy as the Balmer rocks become constricted between the Killala-Baird Batholith and the Faulkenham Lake stock to the southwest.
The mineralized lenses at Starratt extend for approximately 1,200 m strike length, vertical depth of 550 m, with a thickness of 10 m to 15 m.
Mining Methods
- Mechanized Cut & Fill
- Overhand Cut & Fill
- Longhole stoping
- Hydraulic backfill
Summary:
Madsen is proposed to be mined as an underground operation using a combination of longhole stoping (LH) with unconsolidated rock fill, conventional cut and fill (CCF) and mechanized cut and fill (MCF) both using hydraulic and rock fill. A target production rate of 800 t/d is envisioned over an operating mine life of 12-years that will extract 3.5 Mt of ore. LH Stoping, CCF and MCF will account for 25%, 59% and 16% of the total ore production respectively. The Madsen deposit will be accessed by extending the current underground ramp and tying into the existing mine levels spaced approximately every 50 metres. Ore and un- mineralized mine rock will initially only be trucked out of the mine, with shaft hoisting being utilized to bring ore to surface from year 4 onwards. A mix of fully electric and diesel mining equipment will be utilized to reduce ventilation requirements through the mine life.
The ventilation network will require a combination of 3.7 meter and 2.4 meter diameter raises, as well as the ramp to distribute fresh air. The tight-lined ventilation partition of the shaft will be utilized as an exhaust path for the ventilation network. Mine air heaters will be installed at both fresh air intakes.
Longhole Mining
LH will be used where the rock quality and ground conditions allow and where vein geometry is amenable to economic stope design. LH is the highest productivity method selected for the production phase of mining.
LH is the least selective of the mining methods when applied over long vertical distances due to potential drill hole deviation and vein geometry variations. To mitigate these effects, level spacing was limited to 25 m (floor to floor), sill drifts will be driven at 3.0 m W x 3.5 m H giving a maximum vertical hole length of 21.5 m. A minimum stope mining width of 1.7 m was used for design and planning purposes. Where the mineralized vein is less than the minimum mining width internal planned dilution is included to increase the width to the minimum 1.7 m.
The LH mining cycle will begin with blasting the slot raise to provide a free face for the first LH round as well as adequate void for swollen muck. Production blasting will begin at the stope ends and retreat to the cross-cut and/or access. Blasted material will report to the bottom of the stope where load haul dump (LHD) machines will muck the ore via remote control. LHD remote operators will be stationed in either safety cutouts, around the corner, or on pedestals in order to maintain a safe line of site with the LHD. Specific safety aspects of remote operator location will be assessed for each stope prior to mucking.
Top sills will be utilized for drifting, loading, and blasting of the stope below, as well as providing access for LHDs for backfilling. Once the stope below is completed and backfilled, the drift will then be used as a bottom sill for mucking ore from the stope above. In the event a top sill is unavailable, the lower extraction sill may be used to drill up holes. Uphole stopes are planned to be left open, and make up approximately 3% of the total mining reserve by tonnes.
Mechanized Cut and Fill
Overhand MCF mining methods were selected for areas that have lower quality rock and/or where the resource geometry is not amenable to LH. In this method, mining begins at the bottom of the ore block and progresses upward. During the mining sequence, the back of the excavation is temporarily supported using rock bolts before the stope is back filled to form the floor of the next level of mining. Backfill is designed to provide sufficient excavation support and a strong working floor for personnel and equipment. MCF stopes at Madsen will be filled with hydraulic fill, however there is flexibility in this method to allow un- mineralized rock fill when practical.
Stopes are accessed via attack ramps driven at a maximum 15% gradient from a working level or access ramp. Minimum drift size for MCF is 2.0 m W x 2.4 m H. In stopes where the width of the economic mineralization swells wider than the primary drift, the wall would be slashed up to a maximum of 4 m. In areas that are at 4 m W for extended sections, a primary/secondary mining sequence will take place whereby the primary cuts are taken first and filled with a structural cemented backfill. This provides structural wall support to permit mining directly adjacent to the primary cut. 15% of hydraulic fill placed will be structural fill. Wall slashing makes up approximately 16% of the MCF tonnes, and the average slashing width is 0.6 m where it occurs.
Conventional Cut and Fill
Overhand CCF mining was selected for areas not amenable to LH mining or where a significant reduction in development was achieved by vertical development as opposed to the attack ramps used for MCF. Attack ramps used for MCF. In this method two near vertical raises will be driven with a raisebore machine for each stope. For stoping blocks under 5,000 t ore only one raise is planned to be used. A tugger will be installed at the top of the raises to transport supplies up and down the raise. Access ladders will be installed from the top of the raise and any ground remediation / support required can be completed from the top down. The first cut is driven off the raise and advanced along the vein, with ground support installed off the muck pile using jacklegs and stopers. Muck is removed from the stope using slusher machines scraping the muck back to the raise and down the pass. Once the cut is complete fill barricades will be constructed and will form the timbered section of the raise as the cuts advance upwards. Each cut is filled with hydraulic fill.
The Madsen deposit currently has 27 levels that were initially developed from the existing shaft as track drifts. Drifts are on average 2.8 m W x 2.8 m H, level spacing is generally ~50 m (150 ft). A decline ramp extends 130 m below surface in the McVeigh area of the deposit. The current ramp has been driven at a 15% gradient with a curvature radius of 15-16 m. The mine plan will use where possible existing development to access new stopes. Where mobile equipment require access, levels will be slashed to 3.7 m W x 3.7 m H; there are 12,590 m equivalent of level slashing in the mine plan. Areas that are being utilized for ventilation or services will be rehabbed; there are 1,480 m of rehab in the mine plan.
Processing
- Gravity separation
- Concentrate leach
- Agitated tank (VAT) leaching
- Carbon in pulp (CIP)
- Elution
- Carbon adsorption-desorption-recovery (ADR)
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
Flow Sheet:
Summary:
The process plant will include:
- One stage of crushing;
- Two stages of grinding with hydro-cyclone size classification;
- Gravity concentration and Intensive Leach;
- Cyanide leaching and carbon adsorption using carbon-in-pulp (CIP);
- Cyanide destruction, dewatering for hydraulic fill and storage of slurry tailings;
- Carbon acid wash, elution and regeneration; and
- Electrowinning and refining.
The primary crushing plant will have a throughput of 800 t/d with an average life of mine (LOM) head grade of 8.97 g/t Au. The circuit will operate at an availability of 50%, resulting in an hourly throughput of 66.7 t/h. The milling, gravity, leach and CIP circuits will operate 24 hours per day, 365 days per year at an availability of 95%, resulting in an hourly throughput of 35.1 t/h. The carbon plant is expected to transfer 1 tonne of loaded carbon daily to the elution circuit to recover the gold to doré bars.
The primary crushin ........

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Production:
Commodity | Units | Avg. Annual (Projected) | LOM (Projected) |
Gold
|
koz
| 79 | 970 |
All production numbers are expressed as payable metal.
Reserves at February 5, 2019:
Category | Tonnage | Commodity | Grade | Contained Metal |
Probable
|
351,200 t
|
Gold
|
9 g/t
|
1,013,000 oz
|
Indicated
|
7,196,000 t
|
Gold
|
8.9 g/t
|
2,063,000 oz
|
Inferred
|
1,880,000 t
|
Gold
|
7.7 g/t
|
467,000 oz
|
Corporate Filings & Presentations:
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News:
News | Date |
Pure Gold Mining Inc.: First Gold Poured at the PureGold Mine
|
December 30, 2020
|
PureGold Delivers First Ore to the Mill
|
December 16, 2020
|
PureGold Resumes Operations at Site
|
August 17, 2020
|
PureGold Provides Update on Operations
|
August 11, 2020
|
Underground Drilling at PureGold Red Lake Mine Intersects 12.8 g/t Gold Over 10.0 Metres
|
July 28, 2020
|
PureGold Red Lake Mine Achieves Permitting Milestone
|
July 22, 2020
|
Underground Drilling at the PureGold Red Lake Mine Intersects 46.7 g/t Gold Over 7.0 Metres
|
July 7, 2020
|
PureGold Closes $15 Million Non-Brokered Flow Through Financing
|
June 17, 2020
|
Pure Gold Mining Raises $12.3 Million From the Exercise of Share Purchase Warrants
|
May 26, 2020
|
$15M Investment Backed By Eric Sprott To Accelerate Resource Growth At PureGold Red Lake Mine
|
May 20, 2020
|
Canada’s Next Gold Mine on Track for First Gold Pour in Q4
|
May 11, 2020
|
Pure Gold Drilling Intersects High Grade Gold Mineralization at 8 Zone Gap and Wedge
|
December 16, 2019
|
New Gold-Bearing Intercepts Open Up Exciting Target Area at Pure Gold’s Madsen Complex - Drilling Program Expanded to 20,000 Metres
|
October 9, 2019
|
Pure Gold: Drilling Nearly Doubles Strike Extent of Wedge, Extends Madsen Red Lake Mine Gold System to Seven Kilometres
|
October 1, 2019
|
Pure Gold Awards Engineering and Procurement Contracts, Builds Owners Team, and Commences Construction of Its 100% Owned Madsen Gold Mine
|
September 9, 2019
|
Pure Gold Secures US$90 Million Construction Finance Package and Announces Construction Decision for Madsen Red Lake Mine
|
August 7, 2019
|
Pure Gold Intersects Bonanza Grade Gold Including 108.5 g/t Gold Over 1.0 Metre at Madsen Red Lake
|
July 30, 2019
|
Pure Gold Closes Previously Announced Bought Deal Private Placement and Non-Brokered Private Placement Raising Gross Proceeds of C$47.5 Million
|
July 18, 2019
|
Pure Gold Files Amended Technical Report
|
July 5, 2019
|
Pure Gold’s New Discoveries at Madsen-Red Lake Demonstrate Robust Economics
|
February 27, 2019
|
Pure Gold Announces Positive Feasibility Study for the Madsen-Red Lake Gold Deposit
|
February 11, 2019
|
Pure Gold Announces Significant Increase in Mineral Resources at the Madsen Gold Project
|
February 5, 2019
|
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