Overview
Stage | Permitting |
Mine Type | Underground |
Commodities |
|
Mining Method |
- Longhole open stoping
- Longitudinal retreat
- Cemented backfill
- Paste backfill
|
Mine Life | 9 years (as of Jan 1, 2021) |
The Sugar Zone mine is high grade underground mine.
On January 20, 2021, Positive Feasibility Study Results for Expansion to 1,200 tpd were announced.
The expansion can be implemented with amendments to the closure plan, amendments to existing operating permits and a construction permit that is issued following an engineering review, all of which are granted by provincial governmental agencies. There is no requirement for any federal permits or new environmental assessment. |
Source:
p. 40,61
Silver Lake Resources Limited, through its subsidiary Silver Lake Ontario Inc., owns a 100% interest in the Sugar Zone mine.
Contractors
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Deposit Type
- Vein / narrow vein
- Mesothermal
- Orogenic
- Porphyry
Summary:
In the Superior Province, major gold deposits are spatially associated with large-scale regional deformation zones and associated Timiskaming-type metasediments (LeClair et al., 1993). These regional structures are interpreted as zones of transpressive terrain accretion.
Typical greenstone-hosted, mesothermal gold deposits are associated with structurally controlled quartz-carbonate veins hosted by moderately to steeply dipping shear zones displaying brittle to ductile deformational features in low-grade (greenschist) metamorphic rocks. In contrast, the Sugar Zone gold deposit is hosted in medium-metamorphic-grade (amphibolite) rocks that exhibit ductile deformation. The Sugar Zone host rocks have been intruded by felsite and porphyry sills, and exhibit strong association of gold with silica-sulphide-potassic alteration.
The Sugar Zone is interpreted as an orogenic, mesothermal gold deposit located in the SDZ, which is an area of high strain. The auriferous zones of the Sugar zone are interpreted to be highly strained altered mafic flows, intermediate to felsic porphyritic intrusions, and boudinaged auriferous quartz veins. Alteration consists primarily of silicification, biotization, and sulphidization. Hydrothermally altered basalt is recognized as a key component of mineralized zones. Commonly in contact with porphyries within mineralized zones, it is strongly silicified biotitic basalt containing significant amounts of pyrrhotite, and pyrite.
Mining Methods
- Longhole open stoping
- Longitudinal retreat
- Cemented backfill
- Paste backfill
Summary:
The Sugar Zone and Middle Zone mineralization typically comprises tabular, narrow veins, approximately 1.5 m to 3 m thick, and dipping at around 70° to the southwest. Excessive dilution is potentially a major risk to operating success in narrow mineralization. Longitudinal longhole retreat stoping was selected as appropriate for this Deposit based on the favourable geometry, current geotechnical knowledge and success of the Bulk Sample trial mining. Both the ore and the host rock are sufficiently competent to facilitate the void sizes required for effective longhole stoping.
The longhole open stoping mining method provides the following advantages:
- Safe – personnel do not enter the production mining voids (remote-controlled equipment only).
- Proven – many instances of the methods application throughout the world.
- Highly mechanized – reduces personnel exposure to health and safety risks.
- Easy access to resources – skilled labour and equipment are readily accessible locally and around the world.
- Low cost – leverages off large drill and blast scale and minimization of development.
Empirical stope stability analyses by RockEng concluded that, for typical conditions, stopes are expected to perform well:
- Stress in the major influence on stability variability:
-- Above 200 m mining depth stress conditions are favourable (A factor is 0.8–1.0).
-- Between 200 and 500 m mining depth is a transition zone.
-- ........

Source:

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Flow Sheet:
Summary:

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Reserves at December 31, 2020:
Cut-off grade is 5 g/t Au for reported Mineral Reserves.
Cut-off grade is 3 g/t Au for reported Mineral Resources.
Category | Tonnage | Commodity | Grade | Contained Metal |
Probable
|
3.454 Mt
|
Gold
|
7.18 g/t
|
797 koz
|
Indicated
|
2.803 Mt
|
Gold
|
11.87 g/t
|
1,070 koz
|
Inferred
|
1.866 Mt
|
Gold
|
9.45 g/t
|
567 koz
|
Source:

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