Source:
p. 14
The Nash Creek and Superjack Properties which comprise the Project, are 100% owned by Callinex.
Deposit Type
- VMS
- Breccia pipe / Stockwork
- Stratabound (SMS)
- Vein / narrow vein
Summary:
The white smoker deposit model is proposed for the Nash Creek deposit, in contract to a traditional black smoker deposit. These deposits types are described below.
Sulphide mineralization at Nash Creek includes pyrite, sphalerite, galena and minor chalcopyrite. Silver consistently accompanies the sulphides, possibly the result of argentiferous galena or presence of a silver rich sulphosalt. Sulphide concentrations of potential economic interest occur as: 1) stratabound and/or laterally continuous zones of matrix filling or replacement style mineralization within coarse to fine grained pyroclastic deposits of both mafic and felsic affinity; 2) fracture filling, stringer or vein arrays mainly within competent flow units or flow breccia; and 3) discrete breccia zones (e.g., flow breccia, autobrecciation, etc.). Strong intraclast chlorite mineralization is associated with concentrations of zinc and lead in the brecciated mafic rocks.
Moderate to intense clay alteration and silicification are common in the mineralized zones and broader zones of strong carbonate, hematite and potassium alteration occur in footwall, and occasionally hangingwall, to mineralized host rocks. Mineralization occurs as multiple stacked zones of laterally extensive pyroclastic units and flow top rubble zones which are cross cut locally by north, northeast and northwest trending structures that may have acted as pathways for mineralized hydrothermal fluids (Cullen and Barr, 2005).
Four zones hosting stratabound mineralization have been identified on the Nash Creek Property by previous workers. These four zones are, roughly from north to south, the MacMillan, Hickey and Hayes zones and to the east, the Central Zone. Drilling completed by Callinex in 2017 has extended the Hickey Zone to the north.
Mineral resource estimates have been stated for the Hickey and Hayes zones. Walker, 2006 describes the Superjack A Zone as two subparallel, easterly thickening, massive sulphide lenses that strike approximately east-northeast and dip about 80°N. The larger, northern lens has a strike length of approximately 380 m and extends downdip for about 280 m, where intersections of 8.93% Zn over 9.75 m have been reported (McAllister 1960; Mitton 1994). Sulphide intersections in the western end of the deposit are between 0.3 m and 3 m in thickness. Massive sulphides in the deposit are dominated by pyrite but include subordinate pyrrhotite, sphalerite, galena, and chalcopyrite. In the western part of the Superjack A Zone, massive sulphides are immediately overlain by basalt and are underlain by an approximate 20 m thick sericite- or chlorite-altered zone of tuffaceous sedimentary rocks cute by quartz-sulphide veins.
In drill logs, the massive sulphides at the A Zone are described as fine-grained, containing predominantly pyrite with intermittent bands of sphalerite and galena throughout, as well as intermittent disseminated sphalerite and galena throughout. The massive zones occasionally contain quartz-chloritic flooding (<1%). Medium-grained blebby chalcopyrite can frequently be observed at both the upper and lower contacts of the massive zones. The sulphides are locally magnetic due to disseminated pyrrhotite. Stringer sulphides, interpreted as stockwork zones, occur mainly on the footwall, but occasionally on the hanging wall as well; this repeating is likely due to local fold patterns. They are hosted by banded argillite and/or sericite schist. Mineralization at the B and C zones is described very similarly to that in the A Zone. Both contain pyrite-dominated massive sulphides with intermittent sphalerite-galena banding/disseminations. The B Zone contains fewer and thinner stringer sulphide zones than both the A and C zones.
Summary:
The PEA proposes a conventional truck and shovel open pit mining operation with leased-to-own equipment, to extract the potentially economic Mineral Resources at the Nash Creek and Superjack Properties.
The mine plan for the Nash Creek Property has an approximate ten-year production life with total on-site DMS process plant capacity of approximately 1.4 Mt per year.
Initial mining activities will be carried out at the Superjack Property, located approximately 45 km by road southwest of Bathurst.
P&E examined the Mineral Resource block model developed for the Nash Creek and Superjack Properties and developed a series of optimized incremental pit shells for a selection of various zinc equivalent cut-off grades. The optimization analysis included Indicated and Inferred Mineral Resources. For pit optimization, a base case ZnEq cut-off grade of 1.50% for Nash Creek and 2.00% for Superjack was used along with an inter-ramp pit slope of 50°. The Mineral Resources were compared in terms of the total value potentially produced and the related waste/overburden stripping ratios. Of special interest was the rate of increase (or decrease) of certain factors in these comparable pit shells, as the open pit shells were excavated deeper.
Two large pits (Hickey North and Hayes) and one smaller pit (Hickey South) are expected to be developed at Nash Creek and one small, moderate sized pit at Superjack. The proposed open pits will utilize conventional open pit drilling, blasting, loading and haulage technologies and related equipment. The overburden stripped from each pit area would be separately stockpiled for later use as site reclamation material. The mine waste rock would be stockpiled in designated rock storage areas. After four years of operation, the Hickey South Pit at Nash Creek will be available for tailings disposal. The Hickey South pit is expected to have a mined-out volume of 1.7 M m3. For strategic estimation purposes, this pit is assumed to have solid, low permeability rock walls and any potential contaminated pit water is assumed to be hydrologically isolated from ground water resources. At a settled density of 1.6 t/m3, using 90% of the pit, about 2.4 Mt of tailings will be disposed in the Hickey South Pit. After seven years of operation, the Hayes Pit is expected to be completed and this pit is also assumed to be suitable, without major engineering modifications, for DMS rejects and flotation tailings disposal.
At Superjack, approximately 5.8 Mt of rock will be mined, of which 1.3 Mt will be process plant feed. This material may be partially crushed on and will be transported by 40 t capacity highway haulage trucks to the Nash Creek processing plant. If mining is completed in one year, approximately 100 truckloads per day will transit on public roads from the Superjack Property to the Nash Creek processing facility.
PIT DESIGNS
An operational pit design was created using the selected optimized shell as the basis.
Haulage Road:
- Haul Road Width (double lane) - 25 m;
- Haul Road Width (single lane) - 12 m;
- Haul Road Grade (maximum) - 10%.
Overburden Slope:
- Bench Height - 10 m;
- Bench Face Angle - 35º;
- Catch-bench Width - 7.2 m;
- Inter-ramp Angle - 25º.
Rock Slope
- Bench Height (triple bench) - 20 m;
- Bench Face Angle - 75º;
- Catch-bench Width - 11.4 m;
- Inter-ramp Angle - 50º.
Processing
- Flotation
- Dense media separation
Source:
Summary:
The mine plan for the Nash Creek Property has an approximate ten-year production life with total on-site process plant capacity of approximately 1.4 Mt per year.
Conventional three stage crushing will reduce the ‘run-of-mine’ (“ROM”) material to a size that will be suitable for pre-concentration in a DMS plant. The size and design of the DMS facility has not been completed yet and will be subject to the results of future test work on sample ROM material. This study assumes that the lower grade 50% of the process plant feed will be separated and rejected as waste in the DMS facility, with acceptable metal losses.
The resulting DMS concentrate will be reduced in size in a ball mill to a P80 of approximately 70 microns. From there, it will be directed to a rougher-scavenger flotation circuit that will produce a zinc and a lead rougher concentrate. Cleaner flotation circuits will upgrade both concentrates to a marketable grade. The concentrates will subsequently be t ........

Recoveries & Grades:
Commodity | Parameter | Avg. LOM |
Zinc
|
Head Grade, %
| 2.88 |
Zinc
|
Recovery Rate, %
| 90 |
Zinc
|
Concentrate Grade, %
| 53.8 |
Lead
|
Head Grade, %
| 0.62 |
Lead
|
Recovery Rate, %
| 80 |
Lead
|
Concentrate Grade, %
| 50.3 |
Silver
|
Recovery Rate, %
| 25 |
Silver
|
Head Grade, g/t
| 20.3 |
Projected Production:
Commodity | Product | Units | Avg. Annual | LOM |
Zinc
|
Metal in concentrate
|
M lbs
| 77 | 768 |
Zinc
|
Concentrate
|
kt
| | 647 |
Lead
|
Metal in concentrate
|
M lbs
| ......  | ......  |
Lead
|
Concentrate
|
kt
| | ......  |
Silver
|
Metal in concentrate
|
M oz
| ......  | ......  |
Operational Metrics:
Metrics | |
Stripping / waste ratio
| 6.7 * |
Daily mining rate
| 29,000 t * |
Daily ore mining rate
| 3,900 t * |
Waste tonnes, LOM
| 92,925 kt * |
Ore tonnes mined, LOM
| 14,427 kt * |
Total tonnes mined, LOM
| 107,352 kt * |
Daily processing capacity
| 3,900 t * |
Tonnes processed, LOM
| 14,427 kt * |
Annual processing capacity
| 1,425,000 t * |
* According to 2018 study.
Reserves at March 21, 2018:
A cut-off value of 1.50% ZnEq was used as the base case for reporting Mineral Resources.
Category | Tonnage | Commodity | Grade | Contained Metal |
Indicated
|
13,592 kt
|
Zinc
|
2.68 %
|
802,056,000 lbs
|
Indicated
|
13,592 kt
|
Lead
|
0.58 %
|
173,010,000 lbs
|
Indicated
|
13,592 kt
|
Silver
|
17.8 g/t
|
7,801,000 oz
|
Indicated
|
13,592 kt
|
Zinc Equivalent
|
3.21 %
|
963,392,000 lbs
|
Inferred
|
9,140 kt
|
Zinc
|
2.68 %
|
563,360,000 lbs
|
Inferred
|
9,140 kt
|
Lead
|
0.47 %
|
63,766,272 lbs
|
Inferred
|
9,140 kt
|
Silver
|
13.9 g/t
|
5,699,000 oz
|
Inferred
|
9,140 kt
|
Zinc Equivalent
|
3.11 %
|
734,748,000 lbs
|
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