The stratiform, iron-rich deposits in the world are classified as Lake Superior and Algoma types banded iron formations (“BIF”). The BIF are interpreted as finely bedded sedimentary rocks of chemical origin.

The Canadian Lake Superior-type iron formations are the most important source of iron, followed by the deposits of Algoma-type iron formations. Algoma-type iron formations are predominantly found in Archean greenstone belts, while the Lake Superior type is generally of Paleoproterozoic age.

The Lake Superior type of iron formation formed in stable continental shelf and platform settings, whereas the Algoma type is associated with volcanic arcs (tectonically active environment, greenstone belts) or rift zones and related volcanism. However, a complete gradation exists from one type to the other, as the Algoma type iron formation can be deposited at considerable distances from the volcanic centres.

The Algoma deposits are interbedded with felsic to ultramafic volcanic and volcaniclastic rocks, greywacke, black shale, argillite and chert. The Lake Superior iron formation is associated with a variety of shallow marine sedimentary rocks including quartzite, shale and carbonate rocks, and subordinate amounts of felsic to mafic volcanic rocks.

The Lake Superior type, formed on the large areal extents of the platforms, typically have higher lateral continuity and thickness than the Algoma type BIF originating from the more restricted volcanic environment.

The DLIP hosts iron deposits typical of the Algoma type oxide facies, considering the presence of an important volcanic rocks component. However, the large extent of the BIF in the DLIP deposits suggests a setting of deposition in a relatively stable environment. Consequently, the Duncan Lake BIF is interpreted to represent a type half-way between the Algoma and Superior types, sometimes referred to as Carajas iron mineralization. The oxide, silicate, carbonate and sulphide facies are common to both of these groups that contain a minimum of 15% Fe that typically varies between 30 and 35% Fe.

Banded iron formation consists of thin alternating beds of silica (quartz, chert) and iron oxides (magnetite and hematite), with variable amounts of silicate, carbonate and sulphides. The sequences are commonly metamorphosed. Grain size varies according to the degree of metamorphism and iron amphiboles are commonly developed in middle greenschist or higher metamorphic grade rocks.

Iron mineralization within the DLIP property consists of BIF type represented by alternating millimetric to centrimetric bands of quartz and of magnetite with minor amounts of hematite. The DLIP deposits are also associated with silicate and sulphide facies iron formations. The silicates consist mainly of actinolite, tremolite, diopside, grunerite, hornblende, chlorite, epidote, biotite, as well as chlorite-rich mudrocks. The BIF is black to dark blue and becomes dark-green with increased silicate content. It is generally fine-grained, with local variations due to recrystallization in response to contact metamorphism by the felsic intrusions near Deposits 3 and 6. Average head grade varies from 15 to 35% total Fe.

Disseminated sulphides, mostly pyrite, are widespread in the BIF sequence and some of the adjacent waste rocks and represent the main contribution in the sulphur deleterious element to the system.

The chemical analysis established that, on average, the iron formation at DLIP contains very low levels of deleterious elements, in particular phosphorus (0.02% P2O5), manganese (0.03% MnO) and magnesium (0.23% MgO). However, the average sulphur content is elevated. The unweighted average of 3,662 analyses for all deposits yielded 0.78% S in the head grade from core samples. The sequence of the iron-rich units on the DLIP is not clearly defined and is related to a mix of Algoma and Lake Superior types BIF.

The mining method selected for the Project is a conventional open pit drill and blast operation with rigid frame mining haul trucks and hydraulic excavators. Pre-production stripping of waste and overburden material will be mined by a contractor.

Vegetation, topsoil and overburden will be stripped and stockpiled for future reclamation use. The mineralization and waste rock will then be drilled, blasted and loaded into rigid frame haul trucks with face shovel hydraulic excavators. The mineralized material will be hauled to a primary crusher and waste rock will be hauled to the waste dump.

To properly manage water infiltration into the pit, a sump will be established at the lowest point on the pit floor. Water collected in this sump will be pumped to a collection point at surface.

Three SAG mills are used. Each SAG mill (12.2 m x 7.9 m) is equipped with a gearless mo or of 22,000 kW and all required auxiliaries. The -198 mm crushed product will be fed directly by a conveyor into each SAG mill. Water is added to each SAG mill to control the slurry density inside the mill at 72 % solids weight. Each SAG mill will be equipped with a 25 x 12 mm discharge grate and an 8 mm trommel screen with pocket lifter to return the oversize directly inside the mill by means of a sluice through the discharge trunnion of the SAG mill. The trommel undersize is fed to a pump box along with pulping water to maintain the solids at 65% in the pump box. From these SAG Mills discharge pump box, it is pumped onto vibrating screens with an opening of 3.36 mm.

The screens oversize is fed back into the SAG mills and the undersize flows into a pump box from where it is pumped to Cobber Magnetic Separators. The first step of magnetic separation (“cobbing”) will reject about 10% of the liberated nonmagnetic gangue. This gangue (final tails), will flow to a hydroclassifier. The cobber concentrate is directed to the secondary grinding circuit to further liberate the magnetite.

Based on Davis Tube Testwork (“DTT”), grind size of 75 microns was selected to process ROM from Deposit 3. It was also deemed acceptable to blend up to 29% of Deposit 4 mineralization with Deposit 3 mineralization.

The secondary grinding circuit consists of six 9,300 kW ball mills operating in parallel in a closed circuit with hydrocyclones.

Each (7 m x 13.5 m) Ball Mill is equipped with all required auxiliaries. The product of the six ball mills is combined with the Cobber concentrate into six ball mills discharge pump boxes along with pulping water to maintain the solids at 47.5%.

This slurry is pumped to six hydrocyclones clusters where the underflow is returned to the ball mills to be reground.

The magnetic separation circuit is composed of six trains of low intensity magnetic separation (“LIMS”). Each train has six triple drums separators. The slurry feeding the drums is at ± 25% solids from the hydrocyclones overflow. The principal distributor is feeding each train through distributors # 1 to # 6 associated with each magnetic separation train. The magnetic concentrate from each train is the final concentrate and goes directly to the concentrate thickener whereas the non-magnetic (magnetic separation tails) is final tails and go directly to two tailings thickeners.

The iron concentrate is thickened to 65% solids and pumped through a pipeline to the pellet plant which will process the concentrate in two 6 Mtpy pellet production lines. Each pelletizing line consists of vacuum disc filters, mixing units for bentonite and concentrate, balling units to produce green pellets and induration machine to produce the final pellets grading 66.3 % Fe and 5.1% SiO2.