Overview
Status | Temporary Suspension |
Mine Type | Underground |
Commodities |
|
Mining Method |
- Back stoping
- Sill mining
- Paste backfill
|
Production Start | ...  |
Mine Life | 7 years (as of Jan 1, 2020) |
March 30, 2023 - Jervois suspends final construction at Idaho Cobalt Operations (“ICO”) due to continuing low cobalt prices and United States (the “U.S.”) inflationary impacts on construction costs, to prudently preserve the value of ICO's ore body. |
Latest News | Jervois Global: Updated RAM Resource Offers Opportunity to Extend ICO Mine Life April 19, 2023 |
Source:
p. 28
The ICO Property is 100% owned by Jervois Mining USA, a wholly owned subsidiary of Jervois.
Contractors
- Subscription is required.
Deposit Type
- Vein / narrow vein
- Sediment-hosted
Summary:
The Ram deposit is one of the two deposits part of the ICO, the other being Sunshine. Stratigraphy in the Ram deposit area is predominantly medium- to fine-grained metagreywacke (previously described as quartzite) metamorphosed to upper greenschist to amphibolite facies. Stratigraphically, the Ram deposit is subdivided into three zones: Hanging wall, Main and Footwall zones, with each zone containing distinct mineralized horizons.
Sunshine is the second deposit part of the ICO. Stratigraphy, including the BTE horizons, strikes north northwest and dips moderately to steeply to the east-northeast. Individual sulphide-bearing beds may not be continuous over a distance of a few hundred feet. Still, generally, the overall mineralized zones within the BTE horizons can be traced along strike for over 500 m (~1,500 ft).
Mineralization at the ICO is of Type 1 characterized as syngenetic, stratiform/tabular exhalative deposits; however, the presumably associated mafic sequences of the Apple Creek Formation have not been identified at this time. This mineralization is dominantly bedding concordant, and the deposits range from nearly massive to disseminated. Some crosscutting mineralization is present that may be in feeder zones to the stratiform mineralization or may be due to remobilization locally into fracture quartz veins and/or crosscutting structures.
Dominant minerals include cobaltite (CoAsS) and chalcopyrite (CuFeS2). Other minerals present in ........

Mining Methods
- Back stoping
- Sill mining
- Paste backfill
Summary:
The mining methods proposed for the ICO are overhand longitudinal short hole back stoping from 12 ft high sills spaced 36 ft vertically.
The selection of these mining methods for the deposit was determined primarily by the geometry of the mineralised horizons, including factors such as its continuity, dip and width, and the geotechnical parameters of the rock mass.
The ICO is composed of numerous parallel mineralised horizons, with thickness ranging from one foot to more than 12 ft, at an average dip of 55° (Orix 2020). Currently, only the main mineralised horizon (“MMH”) contains the majority of the mineralisation is considered in the mine design, plan and mineral reserve as all of the measured and indicated resource lies within this zone of mineralisation.
The sills and backstops will be completely filled with waste rock and cementitious paste fill. Mining sequencing will be overhand with fully paste filled sills forming crowns to terminate the overhand back stoping in a final retreat blind back stope. The mining method significantly reduces the risk of variability in the orebody through detail mapping and sampling of the orebody from the sills to be developed under geologic control.
The ratio of mineral reserve that will be extracted through short hole back stoping and sill mining methods is 62% and 38% respectively. In combination, these two mining methods provide a production capacity in the underground mine that is higher tha ........

Source:

- subscription is required.
Flow Sheet:
Summary:

- subscription is required.
Reserves at January 20, 2020:
The Cobalt cut-off grade for inclusion in the resource is 0.15%, no consideration of copper or gold content was used in determination of cut-off grade.
Category | Tonnage | Commodity | Grade | Contained Metal |
Proven
|
1.44 Mt
|
Cobalt
|
0.56 %
|
17.9 M lbs
|
Proven
|
1.44 Mt
|
Copper
|
0.67 %
|
21.2 M lbs
|
Proven
|
1.44 Mt
|
Gold
|
0.53 g/t
|
24,633 oz
|
Probable
|
1.05 Mt
|
Cobalt
|
0.53 %
|
12.3 M lbs
|
Probable
|
1.05 Mt
|
Copper
|
0.96 %
|
22.3 M lbs
|
Probable
|
1.05 Mt
|
Gold
|
0.8 g/t
|
26,758 oz
|
Proven & Probable
|
2.49 Mt
|
Cobalt
|
0.55 %
|
30.1 M lbs
|
Proven & Probable
|
2.49 Mt
|
Copper
|
0.8 %
|
43.6 M lbs
|
Proven & Probable
|
2.49 Mt
|
Gold
|
0.64 g/t
|
51,391 oz
|
Measured
|
2.65 Mt
|
Cobalt
|
0.45 %
|
26.2 M lbs
|
Measured
|
2.65 Mt
|
Copper
|
0.59 %
|
34.4 M lbs
|
Measured
|
2.65 Mt
|
Gold
|
0.45 g/t
|
38,000 oz
|
Indicated
|
2.59 Mt
|
Cobalt
|
0.42 %
|
23.8 M lbs
|
Indicated
|
2.59 Mt
|
Copper
|
0.8 %
|
45.7 M lbs
|
Indicated
|
2.59 Mt
|
Gold
|
0.62 g/t
|
51,000 oz
|
Measured & Indicated
|
5.24 Mt
|
Cobalt
|
0.44 %
|
50.1 M lbs
|
Measured & Indicated
|
5.24 Mt
|
Copper
|
0.69 %
|
80.1 M lbs
|
Measured & Indicated
|
5.24 Mt
|
Gold
|
0.53 g/t
|
89,000 oz
|
Inferred
|
1.57 Mt
|
Cobalt
|
0.35 %
|
12 M lbs
|
Inferred
|
1.57 Mt
|
Copper
|
0.44 %
|
15.2 M lbs
|
Inferred
|
1.57 Mt
|
Gold
|
0.45 g/t
|
23,000 oz
|
Proposed Heavy Mobile Equipment:
HME Type | Size | Quantity | Leased or Contractor | Ref. Date |
Bolter
|
|
.......................
|
|
Jan 20, 2020
|
.......................
|
|
.......................
|
|
Jan 20, 2020
|
.......................
|
.......................
|
.......................
|
|
Nov 10, 2017
|
.......................
|
|
.......................
|
|
Jan 20, 2020
|
.......................
|
|
.......................
|
|
Jan 20, 2020
|
.......................
|
|
.......................
|
|
Jan 20, 2020
|
.......................
|
.......................
|
.......................
|
|
Jan 20, 2020
|
.......................
|
.......................
|
.......................
|
|
Jan 20, 2020
|
.......................
|
|
.......................
|
|
Jan 20, 2020
|
.......................
|
|
.......................
|
|
Jan 20, 2020
|
.......................
|
|
.......................
|
|
Jan 20, 2020
|
.......................
|
.......................
|
.......................
|
|
Jan 20, 2020
|
.......................
|
|
.......................
|
|
Jan 20, 2020
|
- Subscription is required.
Corporate Filings & Presentations:
- Subscription is required.
News:
- Subscription is required.