The Crater Lake Project is located 200 km northeast of Schefferville, Québec and is accessible via fixed-wing aircraft or helicopter. The property consists of 96 contiguous claims covering 47.0 km2 and are owned 100% by Imperial Mining Group Ltd.
The property lies in the Churchill Province in the southwestern region of the Mistastin Batholith (1.4Ga). The Mistastin Batholith covers an area of approximately 5,000 km2. The dominant lithologies are granite and pyroxene-bearing quartz monzonite. It is cut by younger biotite hornblende granite, which is in turn cut by a 6 km diameter olivine quartz syenite, the Crater Lake Intrusive Complex. The dominant exposed lithology is a massive syenite, which contains 1 to 10% of interstitial ferromagnesian minerals. A melanocratic unit, ferrosyenite to alkali pyroxenite, contains more than 50% ferromagnesian minerals, including cumulate fayalite, hedenbergite and ferropargasite, occurs as discontinuous layers, sills and amoeboid-like inclusions or dikes. The unit appears to correspond to several concentric magnetic high features observed at the periphery of the Complex related to a caldera collapse ring-dyke structure.
In 2007, as part of a regional evaluation program, one sample collected in the area that is now the Crater Lake Project returned high concentrations of iron oxide and rare earth elements (REE). This information was inherited by Quest Rare Minerals Ltd (QRM) and lead to the “Discovery Outcrop” in 2009. Since 2009, various geochemical and geophysical programs were conducted followed by numerous prospecting, mapping, and diamond drilling programs.
In 2014, QRM intersected a 225 m long scandium (Sc) and REE bearing zone within a thick ferrosyenite layer at the Boulder Zone with a 27.6 m interval grading 351 g/t Sc2O3 and 1.72% REE. Review of the drilling data also returned a 19 m long interval grading 506 g/t Sc2O3 along the western side of the Crater Lake intrusion.
In 2018, Imperial Mining Group conducted a field campaign consisting of detailed prospecting and geological mapping over three highly prospective scandium targets, the TGZ, STG and Northern Target areas. All targets are characterized by large, strongly magnetic anomalies of variable strike length up to 750 metres. A strongly magnetic, iron-rich pyroxenitic boulder was found 300 meters north of the STG Target and returned 920 g/t Sc2O3. This iron-rich sample is very similar in composition and texture to a sample that was located to the northeast of the Crater Lake intrusion (up-ice from this target area), which returned up to 2,506 g/t Sc2O3. No ferrosyenite outcrops or boulders were observed near the Northern Target.
In 2019, Imperial drilled five boreholes on the TGZ target and intersected intervals grading 341 g/t Sc2O3 over 74.9 m (CL19032) and 314 g/t Sc2O3 over 95.5 m (CL19035). Individual assays from this material graded as high as 730 g/t Sc2O3. The mineralized zone has been traced from surface to at least 200 m down-dip and at least 500 m of strike length and remains open at depth and along strike.
In 2020, A four-hole diamond drilling program was undertaken to drill test high-intensity magnetic anomalies at the TGZ, STG, and Northern Target areas. As well, a detailed GPS-positioned ground magnetic survey at 50-m line spacings was completed on the western half the property. This survey provided a better definition of the scandium-bearing ferrosyenite units and the radial faults controlling the concentration of scandium mineralization on the property.
In 2021, Imperial conducted two diamond drilling programs and a field program consisting of detailed mapping and sampling at the STG Target and the collection of a 16-tonne and 2-tonne bulk sample at the STG and Discovery Target, respectively.
The drilling at the TGZ target consisted of a 14 drillhole program for a total of 2,085 m. All drillholes intersected the target ferrosyenite intrusive host rock which show a high degree of Sc grade and homogeneity. The drilling indicates that the TG scandium-rich Zone has a north-northeast strike direction. The widths of the mineralized zone vary between 55 and 135 m in true thickness. Mineralization is open at depth below the 200 m vertical level and along strike and appears as a thickening, conical-shaped body in cross-section.
The exploration work at the STG target consisted of a two-drillhole program followed by surface sampling of ferrosyenite outcrops and the collection of a 16-tonne bulk sample of olivine-rich ferrosyenite. Borehole CL21054 had an impressive intercept of 115.8 m grading 252 g/t Sc2O3 with elevated levels of total rare earth oxides plus yttrium (TREO+Y) of up to 0.475%. The channel sampling of the surface projection of the Sc mineralization, traced over a strike length of over 535 m, returned up to 9.6 m grading 247 g/t Sc2O3 and 0.380% TREO+Y. Finally, a total of 18-tonnes (16-tonne STG and 2-tonne Discovery Target) of the scandium mineralized ferrosyenite bulk sample was shipped and delivered to Sept-Îles, QC for use in a planned Pilot Mill study in 2022.
Best Historical and Imperial Diamond Drill Intersections
TREO + Y %
*Quest Rare Minerals Ltd
Mineral Resource Estimate
Following the 2021 winter drilling program, Imperial Mining forwarded the project data to InnovExplo of Val-d’Or, QC to complete a 43-101 compliant Mineral Resource Estimate (MRE). On September 23rd 2021, Imperial reported the results of their first MRE with an indicated resource of 7.3 million tonnes grading 282 g/t Sc2O3 and an inferred resource of 13.2 million tonnes grading 264 g/t Sc2O3 for the Northern Lobe of the TG Zone (Imperial Reports TG Zone 43-101 Resource Estimate Results).
43-101 compliant resource estimate table
Cut off NSR ($/t)
In 2018 and 2019, Imperial initiated a series of metallurgical tests (Phase 1 and 2) on the scandium rich ore from drill core bulk samples collected from the TGZ target (MET01 and MET02) and the Boulder Scandium Zone (MET02). From the TGZ Target, a scandium mineral concentrate was produced by using simple low-cost magnetic separation techniques. A combination of low intensity magnetic separation (LIMS) and wet high-intensity magnetic separation (WHIMS) produced a mineral concentrate yielding an impressive 88% Sc recovery as well 69% recovery of total rare earth elements (TREE) for one sample. A combination of LIMS and WHIMS on the second sample with differing mineralogy also yielded encouraging recoveries of 78% Sc and 56% TREE. Additional testwork utilizing Sensor-based ore sorting and heavy liquid separation (HLS) methods confirm that X-Ray Transmission (XRT) sensor-based sorting and dense media separation (DMS) offer additional low-cost alternatives for inexpensively producing a mineral concentrate without the need of grinding, chemical reagents or extensive water consumption. DMS separation yielded recoveries of 90.6% Sc and 89.2% TREE in the mineral concentrate.
Phase 3 of the Hydrometallurgical Development Program was conducted in 2021. Results from this work show very high recovery of both scandium and rare earths from samples representing different mineralization types defined in diamond drilling on the property. This innovative process is a two-stage hydrometallurgical extraction method that entails a high-pressure caustic leach (HPC) followed by hydrochloric acid leach of the HPC residue.
The method showed scandium recovery to primary leach solution (PLS) of 87% for MET01, and 84% for MET02 samples.
The recovery of total rare earth element, including yttrium (TREE+Y) of 84%, from both MET01 and MET02 samples.
Imperial Mining is currently working to further optimize the process parameters and develop its hydrometallurgical flowsheet as part of the Hydrometallurgical Development Program.
Research & Development
Since 2020, Imperial has been working with academia, industry, and government agencies on a variety of Research and Development initiatives related to the Crater Lake Scandium-REE Project.
NSERC Alliance Grant, jointly awarded to Imperial in partnership with the W. Booth School of Engineering Practice and Technology at McMaster University, Hamilton, Ontario, for a three-year, $90,000 research program to investigate scandium-aluminum alloy characterization for use in additive manufacturing (AM), also known as 3-D metal printing, applications.
Imperial and partner Eck Industries (“Eck”) have completed a successful series of tests based on scandium-modified aluminum-magnesium (535-series) alloy components and have collected characterization data for the material. The test data shows that the material properties for EV battery box requirements, as specified by a major North American automotive manufacturer, have been met or exceeded.
Imperial and partner FusiA Groupe (“FusiA”), collectively “Consortium”, have been awarded funding, as a Consortium, for a scandium-aluminum material R&D project valued at CAN$2,600,520 from the Next Generation Manufacturing Supercluster (NGEN) which is a program run by Innovation Science and Economic Development Canada (ISED). The project will focus on the industrialization and the development of a vertically integrated supply chain for a scandium-aluminum alloy for 3D printing.
Imperial has partnered with Investment Québec and the Baie-Comeau Regional Industrial Development Agency (“IDM”) to undertake a comprehensive scandium market study. The study will look at the benefits of establishing a North American supply of scandium and scandium-aluminum alloys products and determine the industrial and technological development impacts on the Baie-Comeau region, in general, and the Québec aluminum industry, in particular.
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