Source:
p. 28
The ICO Property is 100% owned by Jervois Mining USA, a wholly owned subsidiary of Jervois.
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 small quantities are pyrite (FeS2), pyrrhotite (FeS), arsenopyrite (FeAsS), linnaeite ((Co Ni)3S4), loellingite (FeAs2), safflorite (CoFeAs2), enargite (Cu3AsS4), and marcasite (FeS2).
Recently, rare-earth minerals have been identified in samples from the deposit as monazite, xenotime and allanite. At this time, these minerals have not been considered for potential recovery as by-products.
Hoy (1995) suggested the following “associated deposit types: Possibly Besshi volcanogenic massive sulphide deposits, Fe formations, base metal veins, tourmaline breccias.”
Mineralogy seen in the 2019 program, as well as recorded in all previous drilling campaigns, fails to mention any tangible content of IOCG related assemblages. Therefore, making it difficult to assign such deposit type to this mineralization.
The current understanding indicates that the Ram area is a Metasedimentary rock hosted Co-Cu-Au package with strata bound zones of semi-massive sulphides. The origins of these deposits are thought to be varied; a range of mineralizing processes, from diagenetic to epigenetic are thought to be involved; however, the sources of the hydrothermal fluids and metals are still enigmatic. (Bookstrom et al. 2016).
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 than the nominal mill capacity (1,200 st/d). The proposed mine working schedule is two 11 hours shifts, seven days a week to provide blast fume clearance between shifts. The mine operating cost estimates have been based on the life of mine schedule, created in Deswik supplied to contractors for tender.
The following bullet points summarise the mine design parameters and criteria for the Ram deposit.
• Cut-off Grade of 0.24% Cobalt Equivalent on a recovered and payable basis derived from a population of stope blocks created in Deswik at 0.30% and 0.32% Co grade cut off.
• Longitudinal Short-hole back stopes at a minimum width of 6 ft to be cast into the sill drift below and mucked before the subsequent blast to minimise ore loss.
• Sill stopes at a minimum width of 15 ft with a shanty back to allow mechanised mining with the selected fleet. Sills to be spaced at nominal 35 ft centres vertically.
• Stope vertical level intervals set at 70 ft between sub-levels and stope blocks generated in Deswik at 24 ft along strike and 12 ft height.
• Only Measured and Indicated mineral resource from the MMH are considered in the mineral reserve estimate.
• Sill Production Advance Rates volumetrically capped at 2,100 ft³ per day per available heading.
• Backstope Production Rates volumetrically capped at 5,000 ft³ per day per available stope.
• Paste Fill Rates capped at 7,500 ft³ per day.
Crusher / Mill Type | Model | Size | Power | Quantity |
Jaw crusher
|
|
|
75 kW
|
1
|
Cone crusher
|
|
|
|
1
|
SAG mill
|
.......................
|
4.62m x 2.5m
|
735 kW
|
1
|
Ball mill
|
|
2.9m x 4.88m
|
551 kW
|
1
|
Summary:
Ore is loaded from a Run of Mine (“ROM”) stockpile on the ramp by Front End Loader (“FEL”) and discharged into the ROM Tip Bin. An angled ROM Static Grizzly protects the ore receiving section from oversize which is placed to the side of the ramp and periodically removed. A fixed speed ROM Vibrating Grizzly Feeder extracts material and discharges the oversize, into the Primary Jaw Crusher. After being recombined with grizzly undersize, all material is then conveyed to the Fine Ore Bin. The Fine Ore Bin provides enough buffer storage time for the operator to load the plant feed and then attend to other duties, while a controlled feed is maintained into the SAG mill.
Ore at a controlled feed rate, together with a controlled quantity of process water, is discharged into the SAG Mill. SAG Mill discharge is trommel screened in order to remove oversize scats. Trommel undersize gravitates into the Mill Product Sump. Combined SAG and Ball mill product slurries are then pumped at a controlled rate to the Mill Product Cyclones.
The Mill Product Cyclones size the mill product slurry in a closed-circuit loop with the Ball Mill. Cyclone underflow gravitates into the Ball Mill Feed Chute while the product overflow is discharged onto the Vibrating Trash Screen which guards the downstream flotation process against tramp oversize such as plastic, woodchips and coarse rock. SAG and Ball Mill trommel oversize scats, as well as Trash Screen oversize, are discharged into containment areas which are periodically cleared by the operator.
Flow Sheet:
Summary:
The concentrator plant is designed to produce a single concentrate product containing copper and cobalt which are derived via a bulk sulphide flotation circuit flowsheet.
Rougher Flotation
Mill final product gravitates in a pipe launder to the concentrator building where the slurry is sampled prior to being discharged into the agitated Flotation Feed Surge Tank. The surge tank provides a buffer capacity to smooth out production surges prior to the flotation circuit. Additional PAX collector is added at a controlled rate into the surge tank, while frother (AF65) is added just prior to the rougher flotation cells.
The slurry is then pumped at a controlled rate to the Rougher Flotation Cells. Copper and cobalt rich froth product are collected and pumped to the Cleaner flotation cells. The Rougher Flotation tails slurry is combined with Cleaner Scavenger flotation tails and pumped to the Thickener Feed Box.
Online slurry analysers located on both the ........

Recoveries & Grades:
Commodity | Parameter | Avg. LOM |
Cobalt
|
Recovery Rate, %
| ......  |
Cobalt
|
Head Grade, %
| 0.55 |
Cobalt
|
Concentrate Grade, %
| ......  |
Copper
|
Recovery Rate, %
| ......  |
Copper
|
Head Grade, %
| 0.8 |
Copper
|
Concentrate Grade, %
| ......  |
Gold
|
Recovery Rate, %
| ......  |
Gold
|
Head Grade, g/t
| 0.64 |
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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
|
|
3
|
|
Jan 20, 2020
|
.......................
|
|
1
|
|
Jan 20, 2020
|
.......................
|
.......................
|
1
|
|
Nov 10, 2017
|
.......................
|
|
2
|
|
Jan 20, 2020
|
.......................
|
|
4
|
|
Jan 20, 2020
|
.......................
|
|
1
|
|
Jan 20, 2020
|
.......................
|
.......................
|
1
|
|
Jan 20, 2020
|
.......................
|
.......................
|
4
|
|
Jan 20, 2020
|
.......................
|
|
1
|
|
Jan 20, 2020
|
.......................
|
|
1
|
|
Jan 20, 2020
|
.......................
|
|
1
|
|
Jan 20, 2020
|
.......................
|
|
1
|
|
Jan 20, 2020
|
.......................
|
.......................
|
6
|
|
Jan 20, 2020
|
- Subscription is required.
Corporate Filings & Presentations:
Document | Year |
...................................
|
2020
|
...................................
|
2020
|
...................................
|
2020
|
...................................
|
2020
|
...................................
|
2018
|
...................................
|
2018
|
Feasibility Study Report
|
2017
|
- Subscription is required.
News:
News | Date |
Jervois orders Metso Outotec SAG mill for Idaho Cobalt Operations
|
January 19, 2021
|
Jervois releases NI43-101 ICO Feasibility Study to SEDAR
|
November 13, 2020
|
Jervois releases BFS for Idaho Cobalt Operations
|
September 29, 2020
|
Jervois Mining increases contained Idaho Measured cobalt resource by 22%
|
January 21, 2020
|
Jervois drilling results from Idaho Cobalt Operations, United States
|
December 2, 2019
|
Jervois Appoints Wood as ICO Refinery Scoping Study Engineer
|
October 15, 2019
|
Jervois update on drilling at Idaho Cobalt Operations, United States
|
October 15, 2019
|
Jervois Mining Closes A$16.5M Capital Raise Including Board and Management Investment of A$2.76M
|
July 30, 2019
|
eCobalt Reaffirms Merger with Jervois is in the Best Interest of eCobalt Shareholders
|
July 12, 2019
|
Jervois Mining and eCobalt To Combine
|
April 1, 2019
|
Construction Continues to Advance at eCobalt's Idaho Cobalt Project
|
August 16, 2018
|
eCobalt Ramps Up Pre-construction Activities At The Idaho Cobalt Project
|
April 23, 2018
|
eCobalt Announces Increase in Measured and Indicated Resources for its Idaho Cobalt Project
|
February 7, 2018
|
eCobalt Solutions Provides Progress Report for Idaho Cobalt Projects
|
November 15, 2017
|
Aerial view:
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