Overview
| Status | Closing / Closed |
| Mine Type | Underground |
| Commodities |
|
| Mining Method |
|
| Processing |
- Spiral concentrator / separator
- Agitated tank (VAT) leaching
- Carbon in pulp (CIP)
- Sand Tailing Retreatment (STR)
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
|
| Production Start | 1983 |
| Mine Life | 2019 |
The mine shut down in 2019 when gold production was no longer economically viable. Public environmental scoping comments on the project closed on March 12, 2021 and the Montana Department of Environmental Quality is currently completing its environmental review.
On February 11, 2022, the pioneering Tailings Reprocessing Project at Barrick’s end-of-life Golden Sunlight Mine was officially opened.
The facility will reprocess the ground rock, known as tailings, from which gold was previously extracted in the Golden Sunlight mills. The focus will be on removing and concentrating sulfur (iron pyrite) to be sold to and used in gold production by Barrick operated and majority owned Nevada Gold Mines, the largest gold producing complex in the world. The concentrated sulfur is not only valuable, but its removal will also eliminate a source of potential groundwater contamination. After reprocessing, the remaining benign material will be backfilled into the Mineral Hill pit. |
| Latest News | Barrick Gold Corp.: Pioneering Mine Closure Project Creates Value While Reducing Environmental Risk March 22, 2021 |
Source:
p. 6
Barrick Gold Corp. is a 100% owner of Golden Sunlight Mine.
Contractors
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Deposit Type
- Vein / narrow vein
- Hydrothermal
Summary:
The Golden Sunlight veins are in a north-trending vein zone on the east side of the mountain, near a basin-margin fault of similar trend. Numerous small latite porphyry bodies in and near the Golden Sunlight mine are hydrothermally altered and mineralized and are the host for about 25 percent of the disseminated ore. About half of the ore body is in a breccia pipe that consists partly of fragmented argillite and partly of fragmented latite porphyry.
Quartz veins in north-trending zone cutting argillite and calcareous argillite of the Proterozoic Greyson Formation and latite of probably Late Cretaceous age. Veins are associated with a breccia pipe that hosts part of a large disseminated gold deposit. Gold is mostly free and associated with pyrite.
Summary:
GSM’s (Golden Sunlight Mine) underground mine, 2BUG (Stage 2B, underground), has implemented vein mining as well as sub-level longhole open stoping for recovering underground ore. Sublevel open stoping is a mining method involving sublevel drifts located above the main haulage road (Hamrin, 2001). The stope drilling is conducted from the sublevel drifts, where ore is blasted in separate portions toward an open face. Once the ore is blasted, gravity causes the ore to pile at the bottom level at the drawpoints located along the haulage route where the ore is collected and transported to the mill for processing.
Stopes at GSM can leave openings as large as 30 m (100 ft.) wide, 60 m (200 ft.) tall, and 60 m (200 ft.) long.
Processing
- Spiral concentrator / separator
- Agitated tank (VAT) leaching
- Carbon in pulp (CIP)
- Sand Tailing Retreatment (STR)
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
Source:
Summary:
The ore treatment plant uses conventional carbon-in-pulp technology as well as Sand Tailing Retreatment (STR), designed to recover gold that would otherwise be lost in the process.
Gold is extracted from ore at GSM using a variety of physical and chemical processes. Ore is first crushed and ground, then gold is extracted using an agitated leach cyanide process.
Initial processing includes a crushing circuit consisting of primary, secondary, and tertiary crushing.
Crushing involves reducing rock particle size using gyratory and cone crushers to minus ¾ inch. Wet grinding in rod and ball mills further reduces rock size to 65 percent passing 100 mesh (150 microns or ~ 0.0058 inch). Grind circuit product is thickened with thickener and overflow is pumped to Carbon Columns where gold is adsorbed onto carbon.
Ground ore slurry is mixed with sodium cyanide, lime, and compressed air in eleven 400,000 gallon leach tanks equipped with agitators to k ........
Recoveries & Grades:
| Commodity | Parameter | 2019 | 2018 | 2017 | 2016 | 2015 | 2014 |
|
Gold
|
Recovery Rate, %
| ...... | 80 | 82 | 78 | 73 | 74 |
|
Gold
|
Head Grade, g/t
| ...... | 2.5 | 2.71 | 2.69 | 1.41 | 1.58 |
Production:
With the end of mining at Golden Sunlight in the second quarter of 2019 as previously reported, Barrick has ceased to include production or non-GAAP cost metrics for this site from July 1, 2019.
| Commodity | Units | 2019 | 2018 | 2017 | 2016 | 2015 | 2014 |
|
Gold
|
koz
| ...... | 32 | 41 | 34 | 68 | 86 |
All production numbers are expressed as metal in doré.
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Operational Metrics:
| Metrics | 2019 | 2018 | 2017 | 2016 | 2015 | 2014 |
|
Ore tonnes mined
| 207 kt | 652 kt | 685 kt | 578 kt | | |
|
Tonnes processed
| 200 kt | 497 kt | 565 kt | 507 kt | 2,059 kt | 2,305 kt |
|
Total tonnes mined
| | | | | 7,401 kt | 6,713 kt |
Reserves at December 31, 2018:
| Category | Tonnage | Commodity | Grade | Contained Metal |
|
Proven
|
263 kt
|
Gold
|
1.06 g/t
|
9 koz
|
|
Probable
|
103 kt
|
Gold
|
3.32 g/t
|
11 koz
|
|
Proven & Probable
|
366 kt
|
Gold
|
1.7 g/t
|
20 koz
|
|
Measured
|
120 kt
|
Gold
|
1.56 g/t
|
6 koz
|
|
Indicated
|
2,777 kt
|
Gold
|
1.77 g/t
|
158 koz
|
|
Measured & Indicated
|
2,897 kt
|
Gold
|
1.76 g/t
|
164 koz
|
|
Inferred
|
1,604 kt
|
Gold
|
1.63 g/t
|
84 koz
|
Commodity Production Costs:
| | Commodity | Units | 2019 | 2018 | 2017 | 2016 | 2015 |
|
Cash costs
|
Gold
|
USD
|
|
1,772 / oz
|
1,270 / oz
|
1,385 / oz
|
1,121 / oz
|
|
Cash costs
|
Gold
|
USD
|
...... †
|
1,762 / oz†
|
1,265 / oz†
|
1,376 / oz†
|
1,098 / oz†
|
|
All-in sustaining costs (AISC)
|
Gold
|
USD
|
|
1,964 / oz
|
1,334 / oz
|
1,502 / oz
|
1,402 / oz
|
|
All-in sustaining costs (AISC)
|
Gold
|
USD
|
...... †
|
1,954 / oz†
|
1,329 / oz†
|
1,493 / oz†
|
1,379 / oz†
|
|
All-in costs
|
Gold
|
USD
|
|
1,964 / oz
|
1,354 / oz
|
1,502 / oz
|
1,402 / oz
|
|
All-in costs
|
Gold
|
USD
|
|
1,954 / oz†
|
1,349 / oz†
|
1,493 / oz†
|
1,379 / oz†
|
† Net of By-Product.
Operating Costs:
| | Units | 2019 | 2018 | 2017 | 2016 |
|
UG mining costs ($/t mined)
|
USD
| 53 | 50.4 | 49.1 | 52.7 |
|
Processing costs ($/t milled)
|
USD
| ...... | ...... | ...... | ...... |
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Financials:
| | Units | 2019 | 2018 | 2017 | 2016 | 2015 |
|
Capital expenditures
|
M USD
| ...... | 3 |
1
|
2
|
7
|
|
Sustaining costs
|
M USD
| ...... | 3 |
|
2
|
7
|
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