The Properties’ deposits are classified as Lake Superior-type. Such iron formations are the principal sources of iron throughout the world. Iron formation deposits in the FIOD include ArcelorMittal’s Mont-Wright and Fire Lake Mines, Mont Reed iron deposits and Cliffs Natural Resources Bloom Lake Mine, (formerly owned by Consolidated Thompson Iron Mines Ltd.) and the Lamêlée Lake and Peppler Lake iron deposits.

Iron formations are classified as chemical sedimentary rock containing greater than 15% iron consisting of iron-rich beds, usually interlayered on a centimetre scale with chert, quartz, or carbonate. Ore is mainly composed of magnetite and hematite, and commonly associated with mature sedimentary rocks.

Stratiform iron formations are distributed throughout the world in the major tectonic belts of the Precambrian shields, and in many Paleozoic and Mesozoic fold belts, as well as parts of the present day ocean floor. Gross (2009) noted that the enormous size of some of the Archean and Paleoproterozoic iron formations reflected the unique global tectonic features and depositional environments for iron formation that were distinctive of the time.

Although various models have been used to explain the deposition of iron formations in the past, current thinking (summarized in Cannon, 1992, Gross, 1996, Gross, 2009) supports the idea of iron formation deposition, resulting from the syngenetic precipitation of iron-rich minerals in a marine setting due to hydrothermal exhalative activity on the ocean floor. The iron is thought to have formed in stable tectonic-sedimentary environments where silica, iron, ferrous and non ferrous metals were available in abundance, mainly from hydrothermal sources, and where conditions were favourable for their rapid deposition with minimal clastic sediment input.

Hydrothermal processes related to volcanism and major tectonic features are thought to be the principal source of iron and other metals. Deep fractures and crustal dislocations over hot spots and high thermal gradients penetrating the upper mantle enabled convective circulation, alteration and leaching of metals from the upper crust, including possible contributions by magmatic fluids. Iron formations are important hosts of enriched iron and manganese ore, gold deposits, and are also marker horizons for massive-sulphide deposits. Deposition of the iron was influenced by the pH and Eh of the ambient water, and biogenic anaerobic processes may have also played a role (Gross, 1996, Gross, 2009).

Post depositional events such as weathering, groundwater circulation and hydrothermal circulation can modify the deposits, and the mineralogy is usually recrystallized and coarsened by medium- to high-grade regional metamorphism. Protracted supergene alteration can be an important economic fact in upgrading the primary iron formation (Gross, 1996).

Iron formations can be subdivided into two (2) types, related to two (2) major types of tectonic environments: the Lake Superior-type on the continental shelf and marginal basins adjacent to deep-seated fault and fracture systems and subduction zones along craton borders; and the Algoma-type along volcanic arcs and rift systems and other major disruptions of the earth’s crust. Development of Lake Superior-types was related to global tectonic systems that caused the breakup of cratons, shields or plates in the Paleoproterozoic. Rapitan-type have distinctive lithological features being associated with diamictite, and were deposited in grabens and fault scarp basins along rifted margins of continents or ancient cratons in sequences of Late Proterozoic and Early Paleozoic rocks.

The mining method selected for the Project is based on conventional drill, blast, load and haul. Annual mining equipment fleet requirements were developed based on equipment performance parameters and average hauling distances.

The mine plan was developed to provide a constant throughput of 23 Mtpy of ROM to the concentrator when mining in the West pit, and 24.8 Mtpy when mining in the East Pit.

The primary equipment at the peak in the mine life consists of 40 x 222 t diesel haul trucks, 2 x 28 m3 bucket rope shovels, 1 x 22 m3 bucket hydraulic electric shovel in ore, 2 x 27 m3 bucket hydraulic electric shovels in waste, a 15 m3 bucket wheel loader and 5 x 12¼ inch rotary blast hole drills.

The mine operating and capital costs have been estimated by BBA and consist of equipment energy, equipment maintenance and replacements, blasting and drilling, personnel, and other costs. It is assumed that the mine equipment will be owned by Champion and the workforce will be directly employed by Champion, except for contracted blasting services.

There are three (3) waste rock piles and one (1) overburden pile that were designed for the Fire Lake North PFS.

The West waste rock pile will be completed first, due to its proximity to the West pit. This will provide shorter hauls at the beginning and middle of the mine life. Subsequently, the central pile will be filled. It lies in between the two pits. The East pile will be used mostly when the East pit is in production. It is located northeast of the East pit exit.

Run-of-mine (ROM) material will be delivered in trucks to either of the two (2) dump points at the 1525 mm x 2260 mm (60” x 89”) gyratory crusher. A hydraulic rock breaker, operated from the crusher operator’s room, will be installed adjacent to the crusher to manipulate lumps in the feed pocket and to break lumps too large to enter the crusher. An overhead crane will be located over the dump pocket and will be used during installation of the crusher and for handling the crusher main shaft and concaves during maintenance periods. An auxiliary hoist will be installed over the hoist well in the crusher building to handle parts for the crusher drive, the discharge apron feeder, crushed ROM conveyor and other ancillary equipment. The crusher building will be enclosed and provided with a baghouse. Floor wash-down water and drainage will be collected in a sump which will periodically be collected by a tank truck and removed from site.

ROM material crushed to -250 mm (10”) in size will be collected in a surge pocket with a two-truck capacity of 640 t below the crusher. From the surge pocket, the crushed ROM will be fed by a 2134 mm (84”) wide apron feeder with a design capacity of 4500 tph onto the 1829 mm (72”) wide fixed-speed crushed rock belt conveyor fitted with a belt scale, belt magnet and metal detector. The conveyor, with walkways on both sides, will be enclosed in an unheated gallery and will discharge onto the crushed ore stockpile. The stockpile will not be covered. The 34 250 t live capacity of the stockpile will be sufficient for approximately 12 hours of operation. This will allow the crusher to be taken out of service for normal maintenance while maintaining the feed to the mill. The total pile capacity will be 85 600 t, sufficient to maintain an uninterrupted feed to the grinding circuit for up to 30 hours. This will allow major repairs to be undertaken on the crusher.

Crushed ore will be withdrawn from the stockpile by three (3) variable speed, 1372 mm (54”) wide apron feeders located inside a heated reclaim tunnel. The apron feeders are sized such that during maintenance, two (2) feeders can provide the full mill-feed capacity of 2854 tph. The apron feeders will feed the crushed material onto the 1829 mm (60”) wide mill feed conveyor at a maximum rate of 3425 dry tph and an average rate of 2854 dry tph. The mill feed tonnage will be controlled electronically by varying the feeder speed with a control signal from the belt weigh scale.

Crushed ore from the stockpile along with oversize material removed from the primary screening will feed the AG mill via the mill feed conveyor. The AG mill will be a 11.6 m x 6.6 m (38’ x 21.5’) mill driven by two (2) dual-pinion, 8.0 MW (10 700 HP) drives for a total installed power of 16 MW (21 450 HP).

The ground material from the AG mill will be discharged onto two (2) 4267 mm x 8534 mm (14’ x 28’) primary scalping screens with 6 mm openings. The oversized fraction from the primary screens will be discharged onto the scalping screen O/S belt conveyor. The undersize material from each screen will discharge into a single pump box. The pump box will feed two (2) separate pumps, each capable of supplying half of the total plant feed. The division of the stream into two (2) parts makes it possible to operate the plant at half capacity during maintenance. All equipment which is downstream of the scalping screen undersize pumpbox (with the exception of the tailings thickener and tailings pumps) has been divided into two (2) circuits to allow for operation at half capacity.

The scalping screen undersize fraction is pumped to an adjacent building and fed to six (6) 4267 mm x 8534 mm (14’ x 28’) multi-slope (“banana”) secondary screens with 850 micron openings (20 mesh). The secondary screens are housed in an adjacent building to minimize the impact of the equipment vibrations within the main concentrator building; vibrations can be amplified when operating at a screen opening size below 1.5 mm. One primary screen pump box feeds three (3) secondary screens. The oversize from the secondary screens is collected onto a belt conveyor along with the scalping screen oversize material. The undersize fraction of the classification screens is collected into two (2) pump boxes, with each pump box collecting material from three (3) secondary screens. This material is then pumped to the gravity spirals circuit.

A conventional gravity circuit flowsheet will be used to produce concentrate from the Fire Lake North deposits. The overall design basis for this project was determined on the basis of 23 Mtpy of feed material to the mill.

Gravity Spirals Circuit
The gravity concentrating circuit layout is based on a conventional, gravity fed, 3-stage spiral circuit. The undersize from the classification screens will be pumped to four (4) primary distributors. The primary distributors feed an additional eight (8) secondary distributors. The secondary distributors will feed 32 banks of 14 double-start rougher spirals (896 total starts). The rougher spirals will produce two (2) products, a concentrate stream and a tailings stream. The concentrate will be collected by a series of launders and directed to the distributors feeding the cleaner spirals. Dilution water will be added in the launders to control the solids density at the cleaner spiral feed at 40% solids (w/w).

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