Overview
Stage | Permitting |
Mine Type | Open Pit |
Commodities |
|
Mining Method |
|
Processing |
- Gravity separation
- Smelting
- Dewatering
- Hydrochloric acid (reagent)
- Intensive Cyanidation Reactor (ICR)
- Carbon re-activation kiln
- Centrifugal concentrator
- Flotation
- Concentrate leach
- Carbon in leach (CIL)
- Elution
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
|
Mine Life | 14 years (as of Jan 1, 2021) |
Latest News | Spanish Mountain Gold Provides Update on Environmental Assessment & Project Optimization June 10, 2022 |
Source:
p. 25
The Property is 100% owned by SMG (Spanish Mountain Gold Ltd.).
Deposit Type
- Sediment-hosted
- Vein / narrow vein
Summary:
The Spanish Mountain gold deposit is classified as a sediment-hosted vein (SHV) deposit, as defined by Klipfel (2005).
Gold mineralization occurs as two main types:
• Disseminated within the black, graphitic argillite. This is the most economically significant form. Gold grain size is typically less than 30 µm, and is often, but not always, associated with pyrite. Disseminated gold has also been associated with quartz veins within faults zones in the argillite.
• Within quartz veins in the siltstone/tuff/greywacke sequences. It occurs as free, fine to coarse (visible) gold and can also be associated with sulphides including galena, chalcopyrite and sphalerite. Highest grades have come from coarse gold within quartz veins.
Disseminated gold within the argillite units is by far the most economically important type of mineralization, and occurs in multiple stratigraphic horizons. From drill core, elevated gold content has been noted within fault zones as well as quartz veins within fault zones. However, the influence of fault zones in relation to the gold content of the deposit is not certain.
Examination of 15 representative core samples of disseminated gold in thin section work by Ross (2006) has concluded the following:
• Native gold (electrum) was identified in four samples, and it occurred as inclusions and fracture fill in pyrite, on crystal boundaries between pyrite crystals and in the gangue adjacent to pyrite. It is very fine grained <20 µm, and generally <5 µm. It is associated with equally fine-grained chalcopyrite-galena-sphalerite, which occurs in all the same habits. All the mineralized samples occurred in variably carbonaceous mudstones/siltstones to fine-grained greywackes, with quartzcarbonate-pyrite veinlets and disseminations. There is no clear indication from this study that the gold is preferentially associated with any habit of pyrite (i.e., disseminated or veinlet, euhedral or subhedral). The deformation state (i.e., degree of cataclastic deformation) of the host rock does not appear to be significant, at least not on the thin section scale; however, a larger scale relationship to position on fold limbs should not be ruled out.
Although a lesser component, quartz veins carrying free gold have yielded the highest grade individual samples on the Property. These veins tend to occur in the more competent facies such as siltstone and tuff/greywacke. The veins are discontinuous on surface and exhibit a strong nugget effect. The veins have been followed with confidence for about 40 m on the Main Zone. Gold is often associated with base metals in these veins. In particular, sphalerite and galena and chalcopyrite are commonly associated with free gold. Geochemically, the base metals are insignificant, but mineralogically they are a good indicator of gold mineralization. It is thought that gold and base metals may have been re-mobilized into these veins.
These veins typically cross cut all foliation fabrics and thus appear to have been emplaced late in the tectonic history. From work done by geological mapping and on oriented core data, it is known that the veins generally strike between 010° and 050°, and dip at various angles to the southeast and northwest. Several “blow out” veins, which are 1 to 5 m in thickness, have been identified on the Main Zone.
Summary:
The Spanish Mountain deposit will be mined using a conventional open pit mining method. A PFS level mine operation design, 14-year open pit production schedule.
The mining fleet will include diesel-powered rotary drills with 200 mm bit size for production drilling and down the hole (DTH) drills with 127 mm bit size for wall control drilling; diesel- powered RC drills for bench-scale grade control drilling; 15.5 m3 bucket sized hydraulic excavators and 13 m3 bucket sized wheel loaders for production loading; 140 tonne payload rigid-frame haul trucks and 40 tonne articulated trucks for production hauling; plus ancillary and service equipment to support the mining operations. In-pit dewatering systems will be established for the pit. All surface water and precipitation in the pits will be handled by diesel powered pumps.
Ore will be hauled to a crusher 0.5 km west of the pit and crushed to feed the process plant. Waste rock will be deposited into waste rock storage facilities (WRSF) 0.5 to 2.0 km west of the pit or used as rockfill to construct a tailings dam 4.0 km southwest of the pit.
Ultimate pit limits are split into phases or pushbacks to target higher economic margin material earlier in the mine life. The pits are split into nine distinct phases, with the initial phases containing mineralisation with a higher gold grade and lower strip ratio than later phases.
During the pre-stripping phase, all ore mined in the pit will be stockpiled. Cut-off grade optimisation on the mine production schedule will also send ore to a high-grade ore stockpile near the primary crusher. The stockpiled Mineral Reserves are planned to be re-handled and fed to the
crusher once the pits are exhausted.
Mining operations will be based on 365 operating days per year with two 12-hour shifts per day. An allowance of 5 days of no mine production has been built into the mine schedule to allow for adverse weather conditions.
Maintenance on mine equipment will be performed in the field with major repairs to mobile equipment in the shops located near the plant facilities.
Annual mine operating costs per tonne mined range from $2.07 to $2.49/t with a LOM average of $2.22/t mined. Mine operations will include grade control and production drilling, blasting, loading, hauling, and pit, haul road and stockpile maintenance functions. Mobile equipment maintenance operations will also be managed by the Owner and are included in the mine planning and costs.
The mine equipment fleet is planned to be purchased via a lease financing arrangement.
Pit designs are completed that demonstrate the viability of accessing and mining the potential resource. The designs are run with the following inputs:
• Suitable single and dual lane haul road widths to handle 140 t payload haulers:
o 22 m for single lane traffic;
o 29 m for dual lane traffic.
• The ramp is not extended into the bottom 10 m of the pit, assuming the ramp will be retreatmined out of these benches.
• The ramp is designed to single- lane width for the 20 m above this, assuming single lane traffic is adequate.
• 10% maximum ramp grade.
• Pit exits face west towards the crusher, stockpiles, and tailings dam.
Flow Sheet:
Crusher / Mill Type | Model | Size | Power | Quantity |
Gyratory crusher
|
|
|
|
1
|
Pebble crusher
|
|
|
600 kW
|
1
|
SAG mill
|
|
30' x 22'
|
10.5 MW
|
1
|
Ball mill
|
|
20' x 26.5'
|
5.25 MW
|
1
|
Regrind
|
|
|
|
1
|
Summary:
Primary Crushing & Stockpiling
The crushing circuit is designed for an annual operating time of 6,132 h/a or 70% availability.
Material is hauled from the open pit and fed to the primary crusher at 1,190 t/h. The crushed material is conveyed to a covered stockpile that provides approximately 12 hours of live storage. The excess crushed material will allow routine crusher maintenance to be carried out without interrupting feed to the mill.
The mill feed stockpile is equipped with apron feeders to regulate feed at 913 t/h into the SAG mill. Crushed material is drawn from the stockpile by two apron feeders and feeds the mill circuit via the SAG mill feed conveyor.
The materials handling and crushing circuit includes the following key equipment:
• primary gyratory crusher;
• mill feed apron feeders (equipped with VSDs);
• materials handling equipment.
Grinding
The grinding circuit consists of a SAG mill followed by a ball mill in closed circuit with hydrocyclones. The circuit is sized based on a SAG F80 of 118 mm and a ball mill product P80 of 180 µm. The SAG mill slurry discharges through a trommel where the pebbles are screened and recycled to a pebble crusher before returning to the SAG mill via conveyor. Trommel undersize discharges into the cyclone feed pumpbox.
The ball mill is fed by the cyclone underflow and discharges through a trommel. The oversize is screened out and discharged to a scats bunker. Trommel undersize discharges into the cyclone feed pumpbox.
Water is added to the cyclone feed pumpbox to obtain the appropriate density prior to pumping to the cyclones and gravity concentrators. Cyclone overflow gravitates to the rougher flotation circuit via a trash screen.
The grinding circuit includes the following key equipment:
• 10.5 MW SAG mill (equipped with VSD);
• 600 kW Pebble crusher;
• 5.25 MW ball mill;
• classification cyclone cluster;
• trash screen.
Processing
- Gravity separation
- Smelting
- Dewatering
- Hydrochloric acid (reagent)
- Intensive Cyanidation Reactor (ICR)
- Carbon re-activation kiln
- Centrifugal concentrator
- Flotation
- Concentrate leach
- Carbon in leach (CIL)
- Elution
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
Flow Sheet:
Summary:
The project will utilise a capital cost-effective mill design, including a target grind size (P80) of 180 µm, gravity concentration in the primary grinding circuit, 4 stages of flotation, flotation concentrate regrind and leaching, flotation cleaner tailings gravity separation, CIL, carbon elution and gold recovery. Leach- adsorption tailings will be treated for cyanide destruction and sent to the tailings pond.
The process design is comprised of the following circuits:
• primary crushing of run-of-mine (ROM) material;
• grinding circuit comprising of a SAG mill followed by a ball mill with cyclone classification;
• gravity and intensive leach circuit;
• 4 stages of flotation: rougher flotation, rougher scavenger, and 2 stage cleaner flotation;
• flotation concentrate regrind and thickening;
• CIL leaching and adsorption;
• acid washing of loaded carbon and pressure Zadra elution and electrowinning followed by smelting to produce dor ........

Recoveries & Grades:
Commodity | Parameter | Avg. LOM |
Gold
|
Recovery Rate, %
| 90 |
Gold
|
Head Grade, g/t
| 0.76 |
Silver
|
Recovery Rate, %
| 40 |
Silver
|
Head Grade, g/t
| 0.71 |
Reserves at March 31, 2021:
Mineral Reserves are reported at a cut-off grade of 0.30 g/t Au.
Mineral Resources at a 0.15 g/t Au Cut-Off Grade.
Category | Tonnage | Commodity | Grade | Contained Metal |
Proven
|
40.8 Mt
|
Gold
|
0.79 g/t
|
1.03 M oz
|
Proven
|
40.8 Mt
|
Silver
|
0.67 g/t
|
0.88 M oz
|
Probable
|
55.1 Mt
|
Gold
|
0.74 g/t
|
1.31 M oz
|
Probable
|
55.1 Mt
|
Silver
|
0.74 g/t
|
1.31 M oz
|
Proven & Probable
|
95.9 Mt
|
Gold
|
0.76 g/t
|
2.34 M oz
|
Proven & Probable
|
95.9 Mt
|
Silver
|
0.71 g/t
|
2.19 M oz
|
Measured
|
68.429 Mt
|
Gold
|
0.59 g/t
|
1.289 M oz
|
Measured
|
68.429 Mt
|
Silver
|
0.67 g/t
|
1.474 M oz
|
Indicated
|
225.724 Mt
|
Gold
|
0.47 g/t
|
3.418 M oz
|
Indicated
|
225.724 Mt
|
Silver
|
0.73 g/t
|
5.298 M oz
|
Measured & Indicated
|
294.153 Mt
|
Gold
|
0.5 g/t
|
4.707 M oz
|
Measured & Indicated
|
294.153 Mt
|
Silver
|
0.72 g/t
|
6.772 M oz
|
Inferred
|
18.343 Mt
|
Gold
|
0.63 g/t
|
0.372 M oz
|
Inferred
|
18.343 Mt
|
Silver
|
0.76 g/t
|
0.448 M oz
|
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