Overview
Stage | Preliminary Economic Assessment |
Mine Type | Open Pit |
Commodities |
|
Mining Method |
|
Mine Life | 8 years (as of Jan 1, 2020) |
Source:
p. 14
The Gold Springs property is held by Gold Springs, LLC (GSLLC), a Nevada limited liability company and wholly owned subsidiary of GRC-US, a Delaware corporation whose name was changed from TriMetals Mining Inc. (TMI-US) on November 4, 2019. Prior to March 17, 2014, GRC was known as South American Silver Corp. and acquired 100% ownership of TMI-US through its acquisition of High Desert Gold Corporation, a Canadian corporation (“HDG”), on December 20, 2013. HDG, GRC-US and Gold Springs, LLC. are now wholly owned subsidiaries of GRC.
Contractors
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Deposit Type
- Vein / narrow vein
- Breccia pipe / Stockwork
- Epithermal
Summary:
Gold mineralization on the Gold Springs project is characterized by structurally controlled vein and stockwork systems that are laterally extensive forming wide corridors of mineralization that are traceable over a strike length of several kilometres. The structural zones are a combination of Basin and Range through-going faults and ring fracture systems associated with caldera margins. Within these structurally prepared zones, mineralization takes the form of discreet veins, breccias, sheeted vein zones, stockwork veins, and zones of disseminations. The veins exhibit quartz, adularia, and low sulfide contents that are typical of a deposit type referred to as “low-sulfidation epithermal deposits” (Robert, et al., 2007).
Mineralization in the Gold Springs area is characterized by large through-going structural corridors hosting veins, breccias, and disseminated gold and silver mineralization in altered rocks. These are generally north-striking faults and structures that are the primary control for the low sulfidation-type gold bearing quartz veins, with subsidiary northeast and northwest striking veins also noted in the target areas. In addition, caldera margins, collapse features, and breccias provide areas of structural preparation and host mineralization within the Grey Eagle resource area. Andesite and latite flows are the primary host rocks to the gold-silver mineralization in the district and were intercepted during drilling conducted by GSLLC at the North ........

Summary:
The Gold Springs deposit is a near-surface epithermal gold system most suitable for open pit mining and heap leach gold recovery. GRE has used that approach for economic analysis.
The schedules for Grey Eagle and Jumbo were broken out into Phase 1 and Phase 2, where Phase 1 included all material within the $700 pit, and Phase 2 included remaining material, approximating a phased pit design. Additional design work will likely better balance the annual leach and waste stripping and metal production.
Pre-stripping of waste and/or tuff was included if either of the following criteria were true: waste or tuff occurred on a bench that had no corresponding leachable material or the tonnage of waste or tuff on a bench exceeded seven times the tonnage of leachable material on that bench. The production rate for pre-strip benches was set to two times the leach material production rate, or 30,000 tpd.
For all other benches, all waste and tuff on a bench were scheduled to be mined over the same duration as the leach material on that bench (i.e., if the leach material mining duration on a bench was 10 days, all waste and tuff on that bench, regardless of quantity, were also mined during those same 10 days). This scheduling method resulted in some years with high waste and/or tuff quantities relative to the leach material quantity mined. GRE used pre-stripping and phasing, as described above, as much as possible to smooth out the production, but the limitat ........

Flow Sheet:
Flow Sheet:
Summary:

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Projected Production:
Commodity | Units | Avg. Annual | LOM |
Gold
|
oz
| 61,269 | 490,152 |
Silver
|
oz
| ......  | ......  |
All production numbers are expressed as metal in doré.
Operational Metrics:
Metrics | |
Daily ore mining rate
| 18.2 kt * |
Daily processing rate
| 18.2 kt * |
Stripping / waste ratio
| 1.6 * |
* According to 2020 study.
Reserves at May 1, 2020:
Category | Tonnage | Commodity | Grade | Contained Metal |
Measured & Indicated
|
35,657 kt
|
Gold
|
0.53 g/t
|
610 koz
|
Measured & Indicated
|
35,657 kt
|
Silver
|
9.4 g/t
|
10,782 koz
|
Measured & Indicated
|
35,657 kt
|
Gold Equivalent
|
0.63 g/t
|
729 koz
|
Inferred
|
5,634 kt
|
Gold
|
0.49 g/t
|
90 koz
|
Inferred
|
5,634 kt
|
Silver
|
7 g/t
|
1,267 koz
|
Inferred
|
5,634 kt
|
Gold Equivalent
|
0.57 g/t
|
104 koz
|
Corporate Filings & Presentations:
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