Overview
Stage | Production |
Mine Type | Underground |
Commodities |
|
Mining Method |
- Cut & Fill
- Drift & Fill
- Post Pillar Cut & Fill
- Backfill
|
Processing |
- Gravity separation
- Dewatering
- Filter press plant
- Smelting
- Agitated tank (VAT) leaching
- Counter current decantation (CCD)
- Concentrate leach
- Merrill–Crowe
- Cyanide (reagent)
|
Mine Life | 3 years (as of Jan 1, 2017) |
Source:
p. 94
Deposit Type
- Hydrothermal
- Breccia pipe / Stockwork
- Vein / narrow vein
Summary:
Mineralization at Joaquin is classified as low sulphidation hydrothermal breccia.
Silver and gold mineralization is hosted within a northwest trending structure that dips approximately 45° to the northeast. The majority of the mineralization is hosted within a silicified breccia, with lesser stockworks and veinlets. Silver is present as native silver, bromargyrite, and acanthite/argentite, with lesser stromeyerite, freibergite, and pyrargyrite/stephanite. The sulphide content is low and consists principally of pyrite and galena. Hematite, jarosite, and manganese oxides are commonly noted. The host minerals are dominated by quartz and feldspar. Hydrothermal alteration is weak to moderate and comprises fine grained replacement quartz and widespread illite and kaolinite alteration.
Mineralization within the economic mine plan is located between approximately 110 m and 310 m below surface and trends for 375 m along strike.
Mining Methods
- Cut & Fill
- Drift & Fill
- Post Pillar Cut & Fill
- Backfill
Summary:
Mining will be undertaken using underground methods with ore hauled by diesel trucks from underground to surface stockpiles. The deposit dips from 40° to 45° and has widths of less than one metre up to 40 m. Three variants of underground cut and fill mining methods were selected to suit this geometry, including traditional cut and fill, drift and fill, and post pillar cut and fill, using mine development waste rock for backfill. All mining is scheduled as a bottom up sequence to avoid leaving sill pillars and to maximize ore recovery. Ore to be transported 145 km by road to the Manantial Espejo plant for processing is estimated to be 474,000 tonnes at 721 ppm Ag and 0.41 ppm Au.
Cut and fill mining will be utilized where the deposit is narrow and dips relatively steeper, to extract 16% of the total recovered stope inventory. A 3.5 m minimum mining width and 4.0 m height was applied, and mining recovery is estimated at 91%.
Drift and fill mining will be used where the deposit has shallower dips and is too wide for standard cut and fill mining, extracting 37% of the total recovered stope inventory. Drifts will be 5 m wide and 4 m high and will require cemented rock fill, batched either on surface or underground in stockpiles adjacent to the fill areas, to enable wider sections to be mined with a higher recovery, estimated at 95%.
Post pillar cut and fill mining with rooms 6 m wide and 4 m high will be used in the widest portions of the deposit, extracting 47% of the total recovered stope inventory. Mining recovery of 81% was assumed primarily to account for the loss of the 4 m by 4 m permanent pillars required for support.
Processing
- Gravity separation
- Dewatering
- Filter press plant
- Smelting
- Agitated tank (VAT) leaching
- Counter current decantation (CCD)
- Concentrate leach
- Merrill–Crowe
- Cyanide (reagent)
Source:
Summary:
As test results have shown that the Joaquin mineralization is amenable to cyanidation, the ore will be trucked to Manantial Espejo and processed at the existing cyanide leach plant on a campaign basis. The mined ore from Joaquin will be stockpiled on a pad at Manantial Espejo and fed with a front-end loader onto a vibratory feeder into the primary crusher. The primary crusher ore will be stored in the covered bin and withdrawn at a rate of approximately 2,160 tpd and ground in a combined SAG mill primary grinding circuit and a ball mill secondary grinding circuit.
The SAG mill operates in closed circuit with a single deck vibrating screen. A split of the SAG mill discharge screen undersize is pumped to the regrind circuit and the rest of the undersize is combined with the ball mill discharge. The screen oversize material will be transported by two conveyors to the pebble crushing system and the product returned to the SAG mill. The ball mill discharge combined with the r ........

Production:
Commodity | Units | LOM (Projected) |
Silver
|
M oz
| 8.9 |
Gold
|
koz
| ......  |
All production numbers are expressed as metal in doré.
Reserves at June 30, 2020:
Category | Tonnage | Commodity | Grade | Contained Metal |
Proven
|
Mt
|
Silver
|
591 g/t
|
0.9 M oz
|
Proven
|
Mt
|
Gold
|
0.15 g/t
|
0.2 koz
|
Probable
|
0.3 Mt
|
Silver
|
546 g/t
|
5.8 M oz
|
Probable
|
0.3 Mt
|
Gold
|
0.35 g/t
|
3.8 koz
|
Measured
|
0.2 Mt
|
Silver
|
356 g/t
|
1.8 M oz
|
Measured
|
0.2 Mt
|
Gold
|
0.19 g/t
|
0.9 koz
|
Indicated
|
0.2 Mt
|
Silver
|
366 g/t
|
1.9 M oz
|
Indicated
|
0.2 Mt
|
Gold
|
0.27 g/t
|
1.4 koz
|
Inferred
|
0.4 Mt
|
Silver
|
351 g/t
|
4.2 M oz
|
Inferred
|
0.4 Mt
|
Gold
|
0.27 g/t
|
3.2 koz
|
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