The LIM deposits are composed of iron formations of the Lake Superior type. The Lake Superior type iron formation consists of banded sedimentary rocks composed principally of bands of iron oxides, magnetite, and hematite within quartz (chert) rich rock, with variable amounts of silicate, carbonate, and sulphide lithofacies.

The earthy bedded iron deposits are a residually enriched type within the Sokoman iron formation that formed after two periods of intense folding and faulting, followed by the circulation of meteoric waters in the fractured rocks. The enrichment process was caused largely by leaching and the loss of silica, resulting in a strong increase in porosity. This produced a friable, granular, and earthy textured iron mineralization. The siderite and silica minerals were altered to hydrated oxides of goethite and limonite. The second stage of enrichment included the addition of secondary iron and manganese, which appear to have moved in solution and filled pore spaces with limonite goethite. Secondary manganese minerals, i.e., pyrolusite and manganite, form veinlets and vuggy pockets. The types of iron mineralization developed in the deposits are directly related to the original mineral facies. The predominant blue granular iron mineralization was formed from the oxide facies of the middle iron formation. The yellowish-brown iron mineralization, composed of limonite-goethite, formed from the carbonate-silicate facies, and the red painty hematite iron mineralization originated from mixed facies in the argillaceous slaty members. The overall ratio of blue to yellow to red iron mineralization in the Schefferville area deposits is approximately 70%:15%:15% but can vary widely within and between the deposits.

The Houston Project focusses on LIM’s more advanced deposits with iron mineralization that is amenable to potential production of lump and sinter products by dry sizing only. Historically, this mineralization was categorized by IOC based on chemical, mineralogical, and textural compositions summarized as follows:

• The blue ores, which are composed mainly of the hematite and martite minerals, are generally coarse grained and friable. They are usually found in the middle section of the iron formation.
• The yellow ores, which are made up of the limonite and goethite minerals, are located in the lower section of the iron formation in a unit referred to as the silicate carbonate iron formation (SCIF).
• The red ore is predominantly a red earthy hematite. It forms the basal layer that underlies the lower section of the iron formation. Red ore is characterized by its clay and slate-like texture.

Conventional open pit mining methods are proposed for the Houston Project. Proposed RoM operations would begin in the Houston 1 pit in July of Year 1, followed by Houston 2 pit in Year 2. Both Houston 1 and 2 were previously permitted. In Year 6, RoM operations move north to the Malcolm pits in Québec, and in Year 8 RoM operations return to Labrador for mining of Houston 3 to the end of RoM operations in Year 12.

Mining operations will be performed by LIM using its own equipment and workforce, with the exception of blasting services, which will be provided by an explosives contractor. LIM will provide the open pit equipment, operator training, supervision, pit technical support services, mine consumables, and the pit operations and maintenance facilities. The downstream activities following mining consist of crushing and screening at the dry sizing plant, product haul to the rail siding, and loading of trains.

RoM operations target production of approximately 2.0 Mdmtpa of high-grade iron mineralization for lump and sinter fines product sales over a 12 year period. Approximately 23.4 Mdmt of high-grade iron mineralization is mined at a diluted grade of 62.2% Fe over the Life-of-Mine (LoM), along with 52.5 Mdmt of waste material. The LoM stripping ratio is approximately 2.2 units of waste to each unit of high-grade iron mineralization (2.2:1). Of note are the very low stripping ratios in Years 1 and 2, at 0.1:1 and 1.2:1 respectively.

PIT DESIGN
Pit designs were completed in Surpac mining software using the Piteau bench scale design recommendations and selected pit shells from the open pit optimization as a guide. A bench height of 10 m was generally utilized with berms at 20 m intervals (i.e., double benched).

The haul ramps were designed for the largest hauling equipment using the road, a 40 t payload capacity truck. For two-way traffic, the industry best practice is to design a travelling surface of at least three times the width of the largest vehicle with the shoulder berm on the outside edge designed to a height equal to three quarters of the rolling radius of the largest tire, along with consideration for ditching and back break. This results in an overall ramp design width of 15 m for the specified haul truck. For access to the bottom benches of the pit, the haul road is narrowed to a width of 9 m, suitable for one-way traffic. The maximum ramp gradient is 10%.

The approximate final pit dimensions are as follows:
• Houston 1 final pit: 100 m deep with a bottom elevation of 495 MASL; pit strike length of 1,010 m.
• Houston 2 final pit: 135 m deep with a bottom elevation of 470 MASL; pit strike length of 460 m.
• Houston 3 final pit: 110 m deep with a bottom elevation of 465 MASL; pit strike length of 1,590 m.
• Malcolm North final pit: 100 m deep with a bottom elevation of 490 MASL; pit strike length of 700 m.
• Malcolm South final pit: 45 m deep with a bottom elevation of 535 MASL; pit strike length of 370 m.

Mining will be accomplished with a maximum of four pit phases in each area to achieve the final pit limits. In general, pit phasing is used to improve economics by targeting higher margin production during the earlier years. The pit phasing has also been used to provide multiple active pit faces to help with product blending at the mine face and to smooth equipment fleet sizing. A minimum mining width of 30 m was used to separate pit pushbacks and allow room for productive mining benches.

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Processing at the Houston Project will comprise dry sizing of high-grade iron mineralization (>58% Fe), represented by DRO samples in metallurgical test work, to produce two products, lump (-31.5 mm +6.3 mm), and sinter fines (-6.3 mm).

Processing will be performed via a dry sizing plant, which will consist of crushing and screening, resulting in two stockpiles, one for each product. The product stockpiles will be recovered by front end loader and loaded into mine trucks for hauling to the rail siding for stockpiling prior to being loaded into rail gondolas. The loaded rail gondolas are defined as the point of sale for the Houston Project PEA.

Processing is currently planned to take place throughout the year, with train loading taking place from May to November. Facilities at the Houston Project will consist of a mobile crushing and screening plant sized to process approximately 6,000 tpd of high grade iron ore mineralization, a railway siding, and utilities.