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The Project is owned by Metallum Resources Inc (Owner), formerly CROPS Inc, who purchased the Property from Superior Lake Resources Limited. The Winston Lake Deposit is currently owned by First Quantum, but the Owner has the option to acquire it.
Summary:
The Project consists of the Pick Lake Deposit and the Winston Lake Deposit.
The Project occurs in Archean rocks of the Southern Superior Province which forms the core of the Canadian Precambrian Shield. It consists of a collage of Archean greenstone belts, that coalesced between 2.72 and 2.68 Ga and were intruded by a complex system of granitoid rocks that were exhumed by approximately 2.48 Ga (Percival, 2007). The Superior Province is particularly well endowed with gold, copper-zinc and nickel deposits, as well as other commodities in lesser amounts.
The Pick Lake and Winston Lake deposits and all nearby prospects are examples of metamorphosed volcanogenic massive sulphide (VMS) deposits, that form in collisional oceanic tectonic environments in areas of localised rifting (Lodge et al., 2014).
The Pick Lake deposit belongs to the bimodal mafic volcanic sub-type, also known as Canadianshield or Noranda-type VMS deposits. The deposits of this sub-type are characterised by dominating of the mafic volcanics with the felsic volcanic rocks constituting less than 25% of the sequence.
PICK LAKE DEPOSIT
The Pick Lake deposit occurs at the extreme western edge of the Winston-Big Duck Lake sequence of volcanic rocks, approximately 35 metres above a granitic contact. Aeromagnetics within the Project area depicts a distinctive “V” shaped sequence of magnetic and non- magnetic units converging to a northern “V” apex and appears remarkably similar to the aeromagnetic character of the older Archean Warriedar Fold Belt in Western Australia which hosts the Golden Grove VMS deposits.
The Pick Lake deposit occurs as a large sheet like zone of massive sulphides within a series of bedded pyroclastic rocks. Hydrothermal alteration exists in both footwall and hanging wall rocks resulting in varying assemblages of quartz, cordierite, biotite, anthophyllite, garnet, chlorite and sericite with minor disseminated sulphides. The hydrothermal alteration zone appears to be spatially related to the Winston Lake deposit; recent structural mapping provides evidence that Pick Lake and Winston Lake may be hosted within the same stratigraphic horizon.
The Anderson showing, located near the southeast shore of Winston Lake, appears to be the surface expression of the Pick Lake deposit. This is a rusty pyritic weakly altered series of bimodal volcanics. Massive sulphides of the Pick Lake deposit occur from approximately 300 m to 1200 m vertically and over a strike length averaging 250 m. The lower portion of the deposit appears to increase in strike length to approximately 500 m. The deposit strikes at 20 degrees and dips to the east at 50 degrees. The thickness of the deposit is generally between 2 and 4 m; however, locally it is up to 14 m.
Sulphide mineralisation is generally very consistent, composed of a fine-grained mixture of sphalerite (50-80%) and pyrrhotite (5-35%) with minor chalcopyrite (0-5%) and pyrite (0-3%). Commonly contained within the sulphides is 5-10% of quartz inclusions, that are represented by the rounded grains up to 3 cm in size and, less commonly, by veins, cutting the massive sulphide mineralisation. Mineralisation also contains inclusions of the host volcanic rocks (1-3%) which are commonly intensely foliated and altered to chlorite-biotite schists. Random orientation of the foliated inclusions indicate that deformation and displacement of the sulphide mass has continued after main peak of metamorphism. Intensity of foliation fabrics increases toward the contact of the massive sulphides, which are typically sharp. The main Zn mineral is sphalerite.
WINSTON LAKE DEPOSIT
The Winston Lake deposit lies at the top of the Winston Lake sequence within cherty exhalite and altered felsic-to-intermediate laminated ash tuff. In places, gabbro forms the hanging wall of the deposit. The footwall consists of altered mafic flow rocks and felsic-to-intermediate volcaniclastic rocks which are underlain by altered quartz and feldspar porphyritic rhyolite and feldspar pyritic basalt with intercalated sulphide-rich, bedded, tuffaceous rocks which, in turn, are underlain by the "Main" quartz feldspar porphyry which is intruded by gabbro and pyroxenite.
High copper values occur at the flanks and top of the alteration "pipe" with the core of the pipe containing relatively depleted copper values. The most common forms of ore are finely banded sphalerite and pyrrhotite and massive-to-coarsely banded sphalerite and pyrrhotite with minor pyrite and chalcopyrite and up to 45% of sub-angular mafic and felsic fragments averaging 3 cm in diameter. The north-striking and 50 degrees eastwardly dipping deposit has a strike length of 750 m and width of 350 m. It has an average true thickness of 6 m and is open to depth.
Hydrothermal alteration, confined to the Winston Lake sequence, and later metamorphism of altered rock have resulted in assemblages of cordierite, anthophyllite, biotite, garnet, sillimanite, staurolite, muscovite and quartz coincident with an increase in iron, magnesium, and potassium and a decrease in sodium and calcium. Zinc content is directly proportional to the intensity of alteration. The recognition of metamorphosed hydrothermal alteration played an important role in the discovery of the Winston Lake deposit (Turcotte and Verschelden, 2013).
Metamorphosed mafic volcanic rocks in contact with the Zenith Gabbro were observed to have unusual mineral assemblages, including the presence of anthophyllite, cordierite and garnet. These rocks were also found to be enriched in Zn, K, Mg and Fe, and depleted in Na and Ca, which defined a zone of hydrothermal alteration associated with a downhole pulse EM anomaly. Drilling of this EM anomaly led to the discovery of the Winston Lake deposit. Further detail on the hydrothermal alteration of the rocks within the Winston Lake Assemblage was obtained by Osterberg (1993). Widespread distribution of altered volcanic rocks have been noted at the Pick Lake deposit, as well as the Rain Mountain, Trail and Ciglen showings (Severin et al., 1991).
Mining Methods
- Sub-level open stoping (SLOS)
- Cemented backfill
Summary:
The Pick Lake deposit is a narrow-vein, Volcanogenic Massive Sulphide (VMS) polymetallic orebody, which suits narrow-vein style extraction. Mechanised narrow-vein sublevel central retreat open stoping with cemented paste fill was selected as the mining method.
Owner mining is proposed for Pick Lake, as a highly skilled workforce is available in the region with a strong mining history. This will enable cost-effective, productive and timely development, which will minimise time to first ore, and with the acquisition of the fleet on a lease basis will minimise capital outlays in the pre-production period.
Ore will be mined and hauled to surface, where it will be processed at the Winston Lake site, producing both a zinc and copper concentrate for sale.
Previous mining activity at both Pick Lake and Winston Lake revolved around shaft and winze access, hence, there is existing infrastructure in terms of capital development. Due to the levels of uncertainty around their condition, and the associated economics, two alternative methods for mine access were assessed at the design stage, noting that the previous Winston Lake plant site has been identified as the prospective process plant location and the bulk of the economic mineralisation is located at Pick Lake.
Two options for ore removal were analysed One option was for the development of a decline from the process plant directly to Pick Lake and the other option was for the refurbishment of the Winston Lake shaft and rehabilitation of the historical rail drive to connect to Pick Lake. The decline option was selected based on shorter construction schedule, better capital cost, transportation of ore through the old workings to the process plant, and additional costs due to dewatering of the old shaft.
Mine development is proposed to be carried out with twin-boom jumbo drill rigs for optimal productivity. The jumbo drill can scale and mesh/bolt a heading, then bore the next cut. Once the heading is charged and fired and re-entry has taken place, an LHD loader unit will muck the heading clean to the nearest stockpile to keep the heading turnover as high as possible. Trucks will then be loaded from the stockpile to haul to the waste destination, which may be to a void backfill area or to the surface waste dumps.
Truck haulage involves a fleet of approximately 40 t trucks hauling mine ore and waste from working areas to the surface via decline. Trucks will be loaded by underground loaders from appropriate stockpiles to keep the loading cycle as short as possible. Once the trucks reach surface, they will haul to either one of the WRD designed on the project lease for waste, or the ROM Pad for ore. Backfill options exist for stopes in the upper areas of Pick, as well as the Alimak stoping void, which would reduce the waste haulage distances.
At each level intersection with the decline, the backs will be stripped to an additional 1m depth for a section 3 m by 2 m, giving clearance for the loader’s bucket over the truck tub. Trucks will wait in the decline while they are loaded from the level stockpile, which is located approximately 20 m back from the decline intersection. Once loaded, the truck will drive up the decline to surface, delivering ore to the ROM Pad and waste to one of the designed Waste Rock Dumps (WRD). If capacity exists for backfill in either historical voids or rock fill stopes in Pick Upper, the truck haul for waste is reduced.
A stockpile of ore will be developed at the primary crusher location on surface, enough to store at least two weeks’ mill feed. Trucks will dump ore at the stockpile, and a Front-End Loader (FEL) will reclaim to the crusher grizzly. Where practicable, the truck haulage fleet will be kept separate from other traffic at the mill to minimise interaction risks associated with mobile equipment.
Paste reticulation runs from the plant (set at Winston headframe) on the side of mine roads to Pick exhaust raises instead of running in the decline to prevent potential high-pressure hazard. Insulation of pipes is required to prevent freezing due to low temperature. Underground paste reticulation runs through service boreholes. Paste is then directed down the borehole to reach theactive mining areas in Pick.
Flow Sheet:
Crusher / Mill Type | Model | Size | Power | Quantity |
SAG mill
|
|
5.49m x 2.9m
|
1400 kW
|
1
|
Ball mill
|
|
1.9m x 3.6m
|
150 kW
|
1
|
Ball mill
|
|
3.2m x 4.4m
|
630 kW
|
1
|
Summary:
CRUSHING CIRCUIT
The crushing plant will be provided and operated by an independent contractor. The plant has been based on a nominal throughput of 53 t/h representing 70% utilisation for a 327,600 tpa throughput.
Ore will be transferred onto the crushed ore conveyor by FEL. In normal operation, the grinding circuit will be fed from the surge bin and the crusher will be operated to generate an excess of feed which will feed the stockpile. The crushing circuit will include a dust collector that will draw fugitive dust from various ore transfer points. The collected dust will be discharged onto the crusher discharge conveyor. The ores are mildly abrasive with Ai value of 0.32. The ROM bin, surge bin and all transfer chutes will incorporate wear liners to prevent potential damage occurring from the coarse rock.
Ore will be withdrawn from the surge bin using a single variable speed reclaim apron feeder. Ore will be transferred onto the mill feed conveyor. A weightometer located on the conveyor will register the instantaneous tonnage rate feeding the grinding circuit and totalise the amount of ore milled during each shift. A second dust collector will be located at the surge bin, with dust being discharged onto the mill feed conveyor.
GRINDING
The grinding circuit design is based on a 365 d/a, 24 h/d operating cycle at a nominal ore throughput of 44 dry t/h (utilisation of 85%) grinding to a nominal P 80 of 75 µm. The grinding circuit will consist of a semi-autogenous grinding (SS SAG) mill operating in closed circuit with hydrocyclones.
Primary crushed ore from the surge bin will be withdrawn by a variable speed single reclaim apron feeder and conveyed to the SAG mill. The mill feed rate will be measured by a weightometer on the conveyor and be controlled to a setpoint by varying the speed.
The SAG mill will be a 5.49 m diameter x 2.90 m EGL unit equipped with a 1,400-kW drive and will operate at up to a maximum 32% volumetric charge loading.
Any pebbles from the SAG mill will be conveyed to a scats bunker for recycling back into the grinding circuit. Provision for addition of milk of lime slurry to the SAG mill feed will be made to assist in depression of pyrite and zinc in the copper flotation. SAG mill product which passes through the SAG mill trommel screen will report to the cyclone feed hopper.
A ball charging system will be provided for addition of 100 mm steel balls to the SAG mill. Grinding media will be loaded into kibbles for hoisting into a dedicated feed chute associated with the mill.
Process water will be added to the slurry in the cyclone feed hopper prior to it being pumped to the cyclone cluster for particle size classification. The cyclone cluster will be comprised of three (3) 250 mm diameter cyclones (2 duty, 1 standby). The cyclone underflow will gravitate to the SAG mill feed chute. Cyclone overflow will be directed to the flotation feed trash screen. Spillage generated within the grinding circuit will be pumped by the area sump pumps to the SAG mill cyclone feed hopper.
COPPER REGRIND
The concentrate from the copper rougher and scavenger flotation banks will be pumped to the copperregrind cyclone feed hopper. The regrind circuit will be designed for a nominal concentrate throughput of 5.5 dry t/h grinding to a nominal P80 of 25 µm.
The ball mill selected for this application will be a 1.9 m diameter x 3.6 m EGL unit equipped with a 150 kW drive. The mill will operate in closed circuit with hydrocyclones.
Process water will be added to the slurry in the regrind cyclone feed hopper prior to it being pumpedto the regrind cyclone cluster using duty standby cyclone feed pumps. The cyclone cluster will be comprised of two (2) 250 mm diameter cyclones (1 duty, 1 standby). The cyclone underflow will return to the regrind mill feed chute while the cyclone overflow will report to the cleaner flotation circuit. A ball charging system will be provided for addition of 30 mm steel balls to the mill. Grinding media will be loaded into a kibble for hoisting into a dedicated ball feed chute associated with the mill.
During mill downtime, a bypass line from the regrind cyclone feed pumps will allow the rougher concentrate to be pumped directly to the cleaners. Slurry to the regrind cyclones will be measured using a magnetic flow meter and density gauge. Water addition to the regrind cyclone feed hopper will be controlled via the SCADA system. Spillage generated within the copper regrind circuit will be pumped via the area sump pump to the regrind cyclone feed hopper.
ZINC REGRIND
The concentrate from the zinc rougher and scavenger flotation banks, along with the return slurry sample stream, will be pumped to the zinc regrind cyclone feed hopper. The regrind circuit is designed for a nominal concentrate throughput of 25.1 dry t/h grinding to a nominal P80 of 38 µm.
The ball mill selected for this application will be a 3.2 m diameter x 4.4 m EGL unit equipped with a 630-kW drive. The mill will operate in closed circuit with hydrocyclones.
Process water will be added to the slurry in the regrind cyclone feed hopper prior to it being pumped to the regrind cyclone cluster. The cyclone cluster will be comprised of four (4) 250 mm diameter cyclones (3 duty, 1 standby). The cyclone underflow will return to the regrind mill feed chute while the cyclone overflow will report to the zinc cleaner conditioning tank 1. A ball charging system will be provided for addition of 30 mm steel balls to the mill. Grinding mediawill be loaded into kibbles for hoisting into a dedicated ball feed chute associated with the mill.
During mill downtime, a bypass line from the regrind cyclone feed pumps will allow the rougher concentrate to be pumped directly to the zinc cleaner circuit. Slurry to the regrind cyclone cluster will be measured using a magnetic flow meter and density gauge. Water addition to the regrind cyclone feed hopper will be controlled via the SCADA system. Spillage generated within the zinc regrind circuit will be pumped via the area sump pump to the regrind cyclone feed hopper.
Processing
- Filter press plant
- Dewatering
- Flotation
Flow Sheet:
Summary:
The processing facilities are based upon the sequential flotation of underground ore from the Pick Lake deposit to produce separate copper and zinc concentrates.
The process plant consists of a mineral processing flotation concentrator with associated services and ancillaries. The plant has been designed to take ROM ore from the underground mine and upgradethe copper and zinc bearing minerals to produce a copper concentrate, a zinc concentrate, and a barrentail.
Haul trucks will deliver underground ROM ore via the decline to the ROM pad where it will be dumped in blending 'finger' stockpiles arranged by grade, lithology and grindability to facilitate blending. A front-end loader (FEL) will be used to reclaim and tram ore from the various stockpiles to the crushing circuit. Primary ore will be blended under the guidance of the plant metallurgist to maintain a relatively constant feed grade and grindability to the process plant.
FLOTATION CIRCUIT FEED
Recoveries & Grades:
Commodity | Parameter | Avg. LOM |
Zinc
|
Recovery Rate, %
| 93.9 |
Zinc
|
Head Grade, %
| 13.7 |
Zinc
|
Concentrate Grade, %
| 52 |
Copper
|
Recovery Rate, %
| 78.4 |
Copper
|
Head Grade, %
| 0.62 |
Copper
|
Concentrate Grade, %
| 26 |
Gold
|
Recovery Rate, %
| 35.8 |
Gold
|
Head Grade, g/t
| 0.21 |
Silver
|
Recovery Rate, %
| 37 |
Silver
|
Head Grade, g/t
| 26.7 |
Reserves at October 15, 2020:
Mineral Resources estimated and reported with using 3% Zn as a lower cut-off.
Ore Reserves are based solely on Indicated Mineral Resources and are reported above cut-off grade 5.2% Zn.
Category | Tonnage | Commodity | Grade |
Probable
|
1.96 Mt
|
Zinc
|
13.9 %
|
Probable
|
1.96 Mt
|
Copper
|
0.6 %
|
Probable
|
1.96 Mt
|
Gold
|
0.2 g/t
|
Probable
|
1.96 Mt
|
Silver
|
26.2 g/t
|
Indicated
|
2.07 Mt
|
Zinc
|
17.9 %
|
Indicated
|
2.07 Mt
|
Copper
|
0.8 %
|
Indicated
|
2.07 Mt
|
Gold
|
0.4 g/t
|
Indicated
|
2.07 Mt
|
Silver
|
33.6 g/t
|
Inferred
|
0.27 Mt
|
Zinc
|
16.2 %
|
Inferred
|
0.27 Mt
|
Copper
|
1 %
|
Inferred
|
0.27 Mt
|
Gold
|
0.3 g/t
|
Inferred
|
0.27 Mt
|
Silver
|
37.2 g/t
|
Corporate Filings & Presentations:
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2021
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2021
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2019
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- Subscription is required.
News:
News | Date |
Metallum Resources Inc.: NPV(8) increases to C$383M(1,2) with average EBITDA of C$102m pa(3) for Superior Lake Zinc Project
|
May 17, 2022
|
Metallum Resources completes $5.2 million private placement to advance the development of the Superior Lake Zinc Project and Board changes
|
April 21, 2022
|
Metallum Resources increases proposed non-brokered private placement financing to $5.242 million
|
April 8, 2022
|
Metallum Resources announces proposed $5 million Non-brokered Private Placement Financing
|
March 21, 2022
|
Metallum Resources Announces Extension of Winston Lake Option Agreement with First Quantum Minerals
|
February 14, 2022
|
Metallum Files Feasibility Study Technical Report for Superior Project, Ontario: After Tax IRR of 23%, NPV 8% at $131.3M, payback 3 years - Base Case
|
October 14, 2021
|
Metallum Delivers Positive Feasibility Study for Superior Project, Ontario: After Tax IRR of 23%, NPV 8% at $131.3M, payback 3 years - Base Case
|
September 15, 2021
|
CROPS Completes Acquisition of the Superior Lake Zinc Project, Concurrent Financing, Share Consolidation, and Name Change to Metallum Resources
|
April 1, 2021
|
CROPS Provides Update on Proposed Acquisition of the Superior Lake Zinc Project and Concurrent Financing
|
March 22, 2021
|
Crops Provides update on Proposed Acquisition of The Superior Lake Zinc Project and Concurrent Financing...
|
January 26, 2021
|
Crops Provides Update on Proposed Acquisition of The Superior Lake Zinc Project
|
November 9, 2020
|
Crops Provides Update on Proposed Acquisition of the Superior Lake Zinc Project
|
October 9, 2020
|
CROPS Announces Transformative Acquisition of the Superior Lake Zinc Project
|
September 9, 2020
|
Superior Lake delivers high-margin potential at zinc project
|
August 28, 2019
|
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