Deposit Types
Frontier Lithium’s target or deposit model is the highly evolved, granitic, rare-element lithium-cesium-tantalum bearing (LCT) complex type, petalite subtype pegmatite. The Tanco pegmatite situated in the Bird River belt in southeastern Manitoba is the best known and a world-class example of this type of deposit model.

Of the five classes, the rare-element class is the group with the most attractive economic potential and can represent economic sources of tantalum, ceramic grade spodumene, rubidium, and the main cesium ore mineral, pollucite.The lithium rich, rare-element pegmatites are not common and comprise <0.1% of the total known pegmatites (Kesler, et al, 2012).

The rare-element class of granitic pegmatites is generated by the differentiation of fertile, S-type granitic plutons. This differentiation process of the parental granite is accompanied by the progressive accumulation of lithophile rare-elements as well as elements such as thallium, tantalum, hafnium, gallium, germanium, boron, fluorine, and phosphorus (Cerný and Ercit, 2005). The pegmatite field results when the lithophile rare-element enriched residual melt is expelled from the fertile granite and assuming suitable channels exist migrates outward and upward away from the granite.A field can be comprised of many pegmatites over a distance of a few kilometres from the source granite. The field itself shows an increasing fractionation moving away from the source granite.

The economic concentrations of the lithophile rare-elements will occur in pegmatites crystalizing from the most highly evolved melts. Some of the lithophile rare-elements may occur in separate zones, which may allow for selective exploitation. Economic tantalum mineralization can be complex and the host mineralogy for rubidium can be different in different zones, but pollucite is the main cesium mineral and according to Kesler et al (2012) spodumene is the most economically important lithium mineral.

PAK Pegmatite Mineralization
Upper Intermediate Zone (UIZ)
The Upper Intermediate Zone (“UIZ”) represents the lithium zone within the pegmatite and is dominated by “SQUI” (Spodumene + Quartz Intergrowth), a term used to describe anisochemical reversion resulting in the replacement of primary petalite by oriented spodumene + quartz intergrowth (London, 1984), with lesser grey K feldspar and primary white spodumene in quartz. Phosphate minerals such as montebrasite (Breaks et al., 1999) and apatite, and lithian mica are common accessory minerals.

Central Intermediate Zone (CIZ)
The Central Intermediate Zone (“CIZ”) is located in structurally higher portions of the pegmatite and represents the tantalum and rubidium zone of the pegmatite. The CIZ is in contact with both the Upper Intermediate Zone (UIZ) and Upper Wall Zone, and persists to the southeast edge of the outcrop where it is believed the pegmatite continues under the till cover.To the southeast, the CIZ is intersected by channels CH-1 and CH-7 where it consists of similarly sized fragments of randomly oriented coarse K-feldspar + mica + quartz. Micas appear to alter primary K-feldspar.Blue apatite prisms up to 1 cm wide and several cm’s long accompany the mica-rich zones.In the adjoining area to the northeast of CH-7, the K-feldspars are more or less completely replaced with lithian mica + quartz. In this area veinlets and patches of lepidolite are common. Channel 1 (CH-1) contains the highest tantalum grades found to date in the exposed pegmatite, which persist in the subsurface in drillholes PL13-001 and -006, in addition to high rubidium and elevated cesium grades.To the northwest, channels CH-8 and CH19 intersect the central portion of the exposed CIZ where it consists of predominantly grey K-feldspar with minor lithian mica + quartz alteration. Drillholes PL13-004 and -003 confirm the extension of the CIZ into the subsurface in this area, where it features notable cm-scale blebs of the rare cesium mineral pollucite, and high tantalum and rubidium grades.

Lower Intermediate Zone (LIZ)
The Lower Intermediate Zone (LIZ) comprises the bulk of the exposed pegmatite and is considered an intermediate stage zone with significant lithium, tantalum and rubidium.The zone comprises predominantly K-feldspar, Na-feldspar, SQUI and lithian muscovite. Pollucite also occurs in an intersection of LIZ in drillhole PL13-005. The zone has undergone both ductile and brittle deformation at the apparently structurally lowest portions of the pegmatite. Ductile deformation is manifested as a banded appearance on surface, where seams of oriented mica provide a planar fabric.

Wall Zones
The Wall Zones (upper and lower) of complex LCT type pegmatites are generally characterized by the occurrence of brick-red K-feldspar (perthite) and simple mineralogy (Cerný, 2005, Cerný and Vanstone, 1996). The zone mineralogy is simple, but the brick-red colouration of the K-feldspar is more common in the portion of the pegmatite in close proximity to the metasediments.

The Upper Wall Zone found in the southwest portion of the pegmatite exposure, is in contact with the lithium rich UIZ and is composed of quartz with lesser pale-red coloured K-feldspar, minor phosphates and accessory beryl and lithian mica. The exposure of this zone is limited.

The Lower Wall Zone is mineralogically similar to the Upper Wall Zone.A common feature of the footwall Wall Zone in the more complex LCT-type pegmatites is the presence of bands of sodic aplite (“footwall aplite”). These sodic bands are generally not common in the Upper Wall Zone. The Pakeagama Lake pegmatite is somewhat more complex as bands of what appears to be pre-existing banded sodic aplites are found throughout the pegmatite. The contact with the LIZ is gradational and is defined by the general absence of SQUI within the wall zones and the change in colour of the K feldspars from pale-red to the light grey commonly found throughout the pegmatite. Like the LIZ, this zone has undergone deformation.

Spark Pegmatite Mineralization
Two predominant lithologies occur within the Spark pegmatite. These are an early aplite that occurs ubiquitously throughout the pegmatite with what appears to be a later phase of coarser-grained feldspar quartz-spodumene-muscovite overprinting the aplite. The aplite ranges from grey to greenish-grey to purplish-grey and is dominated by fine albite and quartz. Intervals containing abundant fine- to coarse grained muscovite are common, and pink garnets a few millimetres in size are common predominantly in the more quartz-rich aplites. Common accessory minerals in the aplites are black prismatic tourmaline, fluorapatite, and rare coarse-grained lollingite.

The later phase that appears to overprint the aplite at Spark has similar lithology and texture to the Lower Intermediate Zone (LIZ) at PAK and has been geologically classified as such. The LIZ at Spark consists of coarse to megacrystic grey to tan K-feldspar up to 20 cm in size (typically 2-5 cm), common to abundant fine to coarse-grained white to light grey spodumene with varying textures, muscovite, and quartz. K-feldspar and quartz show graphic texture in some intersections. Intervals of aplite up to a couple meters thick also occur in the LIZ at Spark.

There is a narrow interval (around 3 m thick) present at surface and in the subsurface in the western portion of the Spark pegmatite consisting of dark-coloured muscovite, dark grey quartz, megacrystic grey K-feldspar, and common blue apatite. The mineralogy and texture of this interval is similar to the Central Intermediate Zone (CIZ) at PAK. Both aplite and LIZ at Spark are weakly to moderately deformed with a preferred foliation steeply dipping to sub-vertical and trending 070 to 100.

Open Pit mining is the selected method of extraction for this PEA. The underground resource at PEA is not considered as part of this PEA.

The Open Pit mine plan was scheduled on an annual basis for the 25-year pit life of the Pak deposit and 25-year pit life for the Spark deposit.

The mining method selected for the project will be a conventional open pit, truck and shovel, drill and blast operation. Minimal vegetation, topsoil, and overburden will be stripped and stockpiled for future reclamation use. The mineralization and waste rock will be mined with 10 m high benches, drilled, blasted, and loaded into haul trucks with a hydraulic excavator and a loader for back-up.

The PAK Lithium Project is designed as a conventional truck-shovel operation assuming 36 nominal tonnes trucks and 5 m³ shovel. Mining at the PAK open pit is planned to produce a total of 5.5 Mt of material (2.9 Mt of chemical grade at average Li2O grade of 1.75 and 2.6 Mt of technical grade at average of Li2O of 1.90), 33.4 Mt of waste for a 1:6 overall strip ratio, for a period of 24 years (excluding 1 year of pre-production). Mining at the Spark open pit is planned to produce 17.2 Mt of mineralization and 48.6 Mt of waste for a 1:2.82 overall strip ratio, for a period of 23 years. The current life-of-mine (LOM) plan focuses on achieving consistent production rates in the production schedule, as well as balancing grade and strip ratios.

The design parameters include a single ramp width of 10.8 m, road grade of 10%, final bench height of 20 m, targeted mining width average of 120 m, variable slope angles by sector, and a minimum mining width of 20 m (pit bottom).

The stripped surface organics storage area has been designed in three (3) areas. The first to the northeast side of the proposed PAK open pit. The second would be in the vicinity of the mill complex. The third area would be to the south of the Spark open pit. The stripped surface organics piles were designed with an overall slope of 26.6° (2H:1V) with a capacity of 0.8 Mm3, a footprint area of 128,000 m2, a top elevation of 330 m and a maximum height of 26 m for the PAK deposit. An identical design with the PAK organic file was created for the Spark pit with top bench elevation of 360 m. The design and construction of the waste rock area (WRA), overburden area and stockpiles should ensure physical and chemical stability during and after mining activities. To achieve this, the waste areas and stockpiles are designed to account for benching, drainage, geotechnical stability, and concurrent reclamation.

Two (2) major waste rock areas (WRA) have been designed with one located west (West WRA) of the Spark open pit and the other located to the north (North WRA) of the PAK pit. The waste rock areas have been designed with parameters that were derived from previous dump design of existing mines. The approximate total waste that can be accommodated at the West WRA was calculated at 22.4 Mt (8.6 Mm3) and the total at the North WRA was calculated at 5.6 Mt (2.2 Mm3). The surface area for both of WRA is 850,775 square meters.

Mining operations for the Project will be conducted 330 days per year, operating two (2), 12-hour shifts. The mine will require 2 years of pre-production activities before the start of operations at the processing plant. The mine starts in Year -2 to provide waste material for the Phase 1 TMF construction dam construction, haulage and airstrip construction. The mine plan is based on an annual production target of 200,000 tonnes of Spodumene concentrate per year.

PAK Open Pit
The top bench elevation is 318 mASL. The pit access ramp will start from the south and the production will start from bench elevation 310. A single-lane ramp is designed to develop benches from surface down to the 150 m elevation. Waste rock from the PAK open pit will be hauled to the North WRA. A portion of the waste stored at the North WRA will be used for the construction of the TMF. The open pit ore is planned to be hauled directly to the mill complex or stockpiled in case of mill repair or maintenance.

Spark Open Pit
The top bench elevation is 324 mASL. The pit access ramp will start from the west and the ore production will start from bench elevation 324. A single-lane ramp is designed to develop benches from surface down to the 144 m elevation. Waste rock from the Spark open pit will be hauled to the West WRA. The open pit ore is planned to be hauled directly to the ill complex or stockpiled in case of mill repair or maintenance.

Mine Production Schedule
PAK Open Pit
The mine production schedule that was developed for the 25-year life of the PAK open pit mine. The material mined will total 38.9 Mt during the 25 year period ranges from 1.9 Mt in the first year to the 14th year and an average of 1.1 Mt from Year 15 to Year 25. The combined chemical and technical mineralization to be mined for the 25 years life of mine will total 5.5 Mt with the chemical grade average annual grade of Li2O for the varies from 2.58 % to 1.83 % like wise the average annual grade of Li2O for the technical grade varies from 2.73 % to 1.81 % during the 25- year period.

Spark Open Pit
The mine production schedule that was developed for the 24-year life of the Spark open pit mine. The schedule includes a pre-production phase of two (2) years which will be required for pit development/pre-construction. During this period, minimal tonnes of overburden will be stripped. The material mined will total 65.7 Mt during the 24-year period ranges from 3.5 Mt in the first year to 14th year and average of 2.6 Mt from Year 15 to Year 18 and average of 1 Mt tonnes per year from Year 19 to Year 24. The average annual grade of Li2O varies 1.9 % to 1.30 % during the 24- year period.

Crushing
The Crushing circuit is designed to reduce ROM with an approximate moisture content of 5% and a F80 of 400 mm to feed the mill concentrator at a P80 of 13mm.

ROM is transported by truck from the open pits and dumped into a grizzly/hopper prior to the Primary Crusher. Oversized material will be processed with a hydraulic rock breaker installed at the truck dump/grizzly.

A primary jaw crusher will reduce the ROM to a P80 size of 100 mm. The Primary Crusher is a jaw-type, with an average operating capacity of 225 tph. A 12-hour operating day for the crusher is assumed.

From the Primary Crusher, crushed ore drops onto a single-deck screen which classifies undersize to bypass the Secondary Crusher. Deck size for the screen have been selected at 70mm. The single-deck screen is in open configuration to lower the machine load of the Secondary Crusher. The Secondary Crusher is a cone type, with a predicted operating capacity of 175 tph at a closed side setting of 43mm.

Undersize from the Secondary Cone Crusher Feed Screen and product of the Secondary Crusher will report to a closed-circuit configured tertiary screen/crusher system. The Tertiary Crusher Feed Screen size has been selected at 17mm. Screen oversize material will report to the Tertiary Crusher. The Tertiary Crusher is a cone type, with a predicted operating capacity of 350 tph at a closed side setting of 20 mm.

Tertiary screen accepts will report to load-out conveyor that carries the material through a heated gallery to a 2500 tonne Fine Ore Storage Bin located prior to the concentrator building. A belt magnet is located on the load-out conveyor to remove tramp ferrous material entrained in the material before it leaves the crusher building complex. A belt weigh scale on the load-out conveyor tracks the production rate of the crushing plant.

A baghouse collects dust at the transfer points within the Primary Crusher Building, which once collected, will report to the tail end of the load-out conveyor.

Grinding
The Grinding Circuit is designed to produce feed slurry fine enough for effective Flotation.

The grinding circuit will employ a single Ball Mill operating in closed-circuit with single-deck screen.

Screen size has been selected at 200 µm. Screen over-size material will report to the Ball Mill, while undersize will proceed to the desliming cyclone feed sump. Product of the Ball Mill will be pumped to a de-sliming cyclone cluster. Cyclone overflows are classified slimes (<10 µm) and report to the tailings thickener. The underflow will feed a Gravity Separator employed to remove tantalum from the flotation feed, prior to the first stage of (Mica) flotation.

Ore from the PAK and Spark deposit will be processed into concentrate. The main sections of the concentrate flowsheet consist of crushing, dense media separation, grinding, magnetic separation, gravity concentration and flotation. The chemical concentrate will be processed into lithium hydroxide in a chemical plant utilizing a flowsheet marketed by Metso-Outotec.

Concentrator Plant
Escalation of the mill feed rate to 2900tpd can be accomplished via minor changes to equipment sizing. 32% of mill feed is expected to be rejected as a result of the DMS process, thereby reducing the comminution and flotation throughput down to 76 tph on a design basis. The concentrator can be operated to produce both technical grade spodumene (7.2% Li2O) and chemical grade spodumene (6.0% Li2O).

Annual production targets have been set at 20,000 tonnes of technical grade concentrate and 160,000 tonnes of chemical grade spodumene. The concentrator will operate on a 24 hours per day ........