The Scully Deposit mineralization style is a deposit typical of the Superior-Lake type of Iron Formations.

The Scully Mine lies within the Labrador Trough in Western Labrador. The Sokoman Formation is an iron formation that consists of three iron bearing formations, named the Upper, Middle and Lower Iron Formations. The Sokoman Formation is more than 300 m thick near the Scully Mine and has been subjected to two episodes of folding and metamorphism during the Hudsonian and Greenville orogenies, resulting in a complex structural pattern in the Wabush Area. The younger Menihek and Shabagamo Formations and the older Denault, Attikamagen, and Wishart Formations all outcrop in the vicinity of the mine site. The mineral deposit that defines the Scully Mine consists of folded and faulted stratigraphic beds of iron-bearing units within the regional Sokoman Iron Formation.

The ore minerals are hematite (specularite), magnetite, and martite. The waste minerals are quartz and hydrated iron oxides such as limonite and goethite. Manganese oxides also occur in bands or are disseminated throughout the iron-bearing units.

The Scully Deposit can be divided into two distinct structural areas. Bounded to the east by the Wabush Lake lies a series of northwest- trending folds. This trend continues as far west as the west end of Knoll Lake, where the folds transition to an east-west trend.

The interpretation by O’Leary (1972) explains a series of simple folds in the east plunging gently to the southeast and cut by an almost vertical fault zone, 75 meters wide, which is believed to be barren of ore minerals. The area to the west is described as a succession of a synform, an antiform and a second synform to the south. The axes plunge east in the eastern part of the fold system, and west in the western part.

The most prominent structural feature in the East Pit, geologically, and as far as mining considerations are concerned, is a reversed fault which runs approximately in a northwest direction through the orebody. This fault dips steeply to the east, with the basement rocks thrown up some 75 meters on the western side. The fault is marked by a series of clay seams, varying in color from pink to a light cream. In addition, the fault is characterized by elevated level of manganese, giving assays as high as 6 or 7 percent. The sooty black appearance of the ore against the lighter clay provides a striking contrast and the fault can be traced quite easily along strike as mining advances. A number of small parallel fault zones have been traced.

The operation consists of a conventional surface mining method using an owner mining approach with electric and diesel hydraulic shovels and mine trucks. Some major mine equipment required for the restart of the project, such as drills and hydraulic shovels, are present on site as this equipment was acquired early on in 2017. The study consists of resizing the open pit based on parameters outlined in this study and producing a life-of-mine (“LOM”) plan to fill the mill to capacity subject to constraints with a mining rate of 35 Mtpy.

Drill and blast specifications are established to effectively single pass drill and blast a 12 m bench. For this bench height a 349 mm blast hole size is proposed with a 6.5 m burden by 7.5 m spacing with 1.5 m of subdrill in ore. The blast pattern in waste is identical with adjusted explosive column height. These drill parameters, combined with a high energy bulk emulsion with a density of 1.2 kg/m3 , result in a powder factor of 0.50 kg/t for ore and 0.45 kg/t for waste. Blast holes are initiated with electronic detonators and primed with 450 g boosters. The bulk emulsion product is a gas-sensitized pumped emulsion blend specifically designed for use in wet blasting applications.

The majority of the loading in the pit will be done by two hydraulic shovels equipped with a 24 m3 bucket. The shovels are matched with a fleet of 211 metric tonnes payload mine trucks. The project already owns two 24 m3 hydraulic front shovels (one electric and one diesel) and one 17m3 diesel front shovel. The hydraulic shovels will be complemented by one production front-end wheel loader with a 12 m3 bucket. The truck fleet reaches a maximum of 16 units excluding equipment replacement.

Mining of the Scully Mine is planned with seven pit sectors referred to as Boot Pit, West Pit Extension North, West Pit Extension South, West Pit, South Pit, East Pit West and East Pit East. Mining has taken place in all of these pit sectors except for Boot Pit which was in the Cliffs LOM plan where only initial efforts to strip overburden and prepare production benches had been undertaken.

The pit area measures approximately 5.4 km in an east-west direction and is approximately 2.1 km northsouth in relation to the South Pit. The final pit contains 443.7 Mt of ore at an average grade of 34.83% Fe, 2.58% Mn and 5.43% SAT. This Mineral Reserve is sufficient for a 26 year mine life with possibilities for expansion at higher iron ore prices and the conversion of Inferred Mineral Resources to Measured and Indicated Mineral Resources. A total of 831.4 Mt is to be mined for an overall strip ratio of 0.87:1.

Crushing and Ore Handling
The ore will be hauled by 240 short tonne mine trucks. The trucks will discharge into two 54” x 74” primary gyratory crushers each driven by a 335 kW (450 HP) motor, at a nominal feed rate of 2,150 tph. Each crusher has a capacity of 3861 tph so only one is required to operate. The ore will be crushed at minus 8’’ (203 mm) and will be transferred by two 60’’ belt conveyors to bins ahead of the grinding circuit. Two new hydraulic hammers (one for each crusher) will break down any oversize rocks in the crusher cavity.

The capacity of the crushing circuit is limited at 3200 tph by the transfer conveyors. The crude ore storage bins have to be kept full at all time. There is an excess of 1000 tph compared to the mills throughput to build the storage in the event of feed interruption.

Grinding
From the 22 000 metric tonne capacity crude ore storage bin, the ore is fed by vibratory feeders onto the mill feed conveyors. Each feeds one of the six fully autogenous mills at a rate up to 400 mt per hour per mill. The dimension of each mill is 24 feet in diameter and 8 feet long.

Wet Concentration and Tails Thickener
The first stage of the concentration circuit is the rougher spirals. A total of 960 spirals (160 for each line), supplied by Mineral Technologies were installed in 1998. Spiral tails are pumped to a cyclone where the underflow is pumped to the tailings basin. The overflow is thickened in a 280 ft diameter thickener using flocculent to 35% solids (as original operation) before being pumped to the tailings basin with cyclone underflow. The solids concentration will gradually be increased to 45% to limit the amount of fresh water required to make up for the water sent to the tailings. With the characteristics of the tailings and the dimensions of the thickener, reaching 45% is considered feasible. However, there is an uncertainty that the added load on the rake and the torque increase can be handled by the equipment without modifications. To mitigate this risk, the increase in solids ratio will be performed gradually during the first year and the equipment will be closely monitored.

The pre-concentrated iron-ore from the rougher spirals enters the hydro separators where the lighter waste material is "floated" from the denser iron-ore concentrate through the use of a concurrent upflow of water through a bed of concentrate. The iron-ore concentrate continues to the drum filters, the tails go to the hydrosizer overflow cyclone. A total of 12 Linatex hydrosizers (2 by line), with dimension of 7 feet by 7 feet were installed in 1997.

Dryers
Moist concentrate from drum filters enters the fluo-solid dryers and is dried using hot air which fluidizes a bed of concentrate. A combination of electrically generated steam indirectly and bunker c fuel burners directly heat the fluidizing air. Each fluo-solid dryer can operate independently, but to meet plant capacity rates require that two be operated simultaneously.

The dry pre-concentrate is transferred to the dry concentrate storage bin before going to the dry magnetic concentration.

Dry Concentration
The dry pre-concentre is processed by two series stages of low intensity magnetic separation (“LIMS”), and the LIMS tails are processed by two series stages of high intensity magnetic separation (HIMS).

The Low Intensity Magnetic Separators (LIMS) are fed with ore by the means of the LIMS Vibratory Feeders. The LIMS is the first stage of the Mn Removal Circuit where the magnetite is separated from the ore to produce the LIMS concentrate, while the LIMS tails fall to the second stage of the Mn Removal Circuit, the HIMS Roughers.

The Rougher HIMS Separator is a double drum unit. It receives the LIMS tails which fall by gravity through the two Rougher feed chutes. The Rougher separator is the second stage of the Mn Removal Circuit where hematite is separated from silica and pyrolusite to produce the Rougher HIMS Concentrate, while the Rougher tails that contain silica, pyrolusite and some remaining hematite are sent to the third stage of the Mn Removal Circuit, the Scavenger HIMS.

High Manganese By-Product
During processing, a high manganese by-product will be created at rate of 7 tonne/hr and stored in high manganese stockpile located approximately 250 meters northeast of the concentrator building.

Concentrate Silo Load-Out
The concentrate from dry concentration is transferred by a belt conveyor to the load-out silos over the rail track. The transfer conveyor is equipped with a belt scale to monitor plant production. From the load-out silos, the concentrate is loaded into a freight train for transportation to the port facilities. The load-out silos are equipped with a dust collection system. Out of the five (5) 3000 metric tonne capacity silos, four (4) were used as live storage to fill freight trains (up to 130 cars) while the fifth silo was used as a manual top-off. The new operation will be based on 168 cars freight trains. Two new silos at 3000 metric tonne capacity will be installed to store the required concentrate. This represents more storage capacity than required but it will provide the plant with additional buffer storage.