Georgia Lake spodumene project is a planned open-pit and underground mining operation in the Thunder Bay Mining District of Ontario, Canada.
The project is 100% owned by Rock Tech Lithium, a cleantech company that seeks to produce lithium hydroxide for electric vehicle (EV) batteries.
The company announced the results of a Pre-Feasibility Study (PFS) for the project in November 2022.
The PFS study supported the concentration of spodumene and the viability of lithium mining activities at the Georgia Lake Project. It also estimated a pre-tax net present value (NPV) of $223m and an after tax NPV of $146m for the project.
Rock Tech plans to advance with the mine and conduct a definitive feasibility study for the project. A production decision is expected to be made in 2023.
Location and site details
The Georgia Lake project is located approximately 160km northeast of Thunder Bay, Ontario, Canada. The site is situated within the Thunder Bay Mining Division in NTS sheets 42E05NW and 52H08NE.
Overall, the property consists of 277 unpatented mining claims and 41 leases. The claims include an area of around 54.37km².
Georgia Lake is divided into two segments- Northern Spodumene Pegmatite Area (NSPA) and Southern Spodumene Pegmatite Area (SSPA).
The Georgia Lake deposit was initially evaluated in the 1950’s as a potential source of the lithium mineral spodumene. A drilling programme was conducted in 1955 and 1956 to investigate the spodumene pegmatites. However, the activity did not advance to production.
RockTech acquired the project in 2009 and conducted multiple drilling programmes from 2010.
Additional mapping, drilling and channel sampling activities were carried out from 2014 to 2022.
Geology, Mineralisation and Reserves
According to the PFS of Georgia Lake project, the deposit hosts lithium as Spodumene in pegmatites, which are hosted by metasediments.
The pegmatites are of Albite-Spodumene type.
The property’s mineralisation comprises coarse-grained fresh pale green spodumene crystals that are oriented perpendicular to the strike of the pegmatite dike in homogeneous dikes, and randomly positioned within the inner spodumene zone in simply zoned pegmatite dikes.
The spodumene in the property can be altered to muscovite or fine-grained muscovite.
As of 31 Jul 2022, the mineral resource estimate of the project outlined 10.60 million tonnes (mt) of Indicated Mineral Resource at a grade of 0.88% lithium oxide (Li2O) and 4.22mt of Inferred Mineral Resource at a grade of 1.0% Li2O.
Total Probable Mineral Reserves stand at 7.33mt at grading of 0.82% Li2O.
The mineral resource estimate was prepared based on 312 core drill holes and 858m of trenching executed during the period from 1955 to 2022.
The PFS results support an open pit and underground mine operation at the property over a nine-year mine life and the construction of a 1 million tonne-per-annum (mtpa) spodumene concentrator.
The study particularly considered open pit mining for the MZN, HAR, CON, and LIN60 areas, and underground mining for the MZN, MZSW and CON areas.
The open pit operations are expected to complete in Year 5, while underground mining will ramp-up in Year 4 and complete in Year 9.
Conventional drill-blast cycles will be applied for development and ore production. A stoping sequence will be followed to extract ore to ensure the level below is filled and maintained in advance of the stope above in a bottom-up direction.
Subsequently, the ore will be mucked and loaded using load-haul-dump (LHDs) and transported using 40-tonne trucks. Waste rock will be transferred back into the stopes as unconsolidated rock fill.
The capital costs for the Georgia Lake LOM are estimated to be up to $290.7m, including pre-production capital costs of $192.2m and sustaining capital costs of $98.5m, and closure costs of $10.6m.
Spodumene Concentrator Plant Design
The Georgia Lake Spodumene Concentrator Plant is proposed to be constructed within the Nama Creek property approximately 160km northeast of Thunder Bay. The facility will have a feed capacity of 150 tonnes per hour (t/h) or 1mtpa.
The process plant will use crushing, grinding, density media separation (DMS) and flotation to convert spodumene pegmatite ore into spodumene concentrate.
The project will also include a Tailings Storage Facility (TSF), a single cell, paddock style impoundment with an adjoining Polishing Pond (PP) around 0.8km northeast of the proposed process plant site.
It will also have a warehouse, maintenance shop, administration offices, water treatment plant and a fresh water supply and distribution system among others.
The power infrastructure will include a power transmission line, a substation at the plant site, and distribution lines throughout the site.
The Preliminary Economic Assessment for an integrated lithium hydroxide operation from the Georgia Lake project was prepared by Wave International, DMT and P&E Mining Consultants.
AMC Mining Consultants (Canada) was engaged by Rock Tech to prepare a Pre-Feasibility Study (PFS) that is compliant with Canada’s National Instrument 43-101 (NI 43-101) and Form 43-101F1. Wave, Knight Piésold (KP), Environmental Resources Management (ERM), Environmental Applications Group (EAG) and Pinchin also contributed.
In August 2022, Rock Tech entered into an agreement with Mercedes-Benz to deliver up to 10,000 tonnes per year of its planned lithium hydroxide production from 2026.