DEFENSE METALS CORP. Defense Metals Corp. provided an update on the metallurgical work programs, undertaken by SGS Canada Inc. (SGS) and the ongoing Preliminary Feasibility Study (PFS) work by SRK Consulting (Canada) Inc. (SRK) and Hatch Limited (Hatch), for its wholly-owned Wicheeda Rare Earth Element Project located in British Columbia, Canada. The metallurgical test work required for the PFS has been completed.
Multiple bench-scale flotation and flotation pilot plant test work resulted in the production of a high-grade mineral concentrate containing 50% Total Rare Earth Oxide (TREO) with an 80% recovery rate, which will be included in the PFS for the first 8 years of mine-life. Bench-scale and hydrometallurgical pilot plant test work shows that the planned acid bake process will deliver approximately 90% TREO extraction from the mineral concentrate to a Mixed Rare Earth Carbonate product. The PFS plant flowsheets are completed, based on the metallurgical test work, and equipment specifications have been issued to vendors for cost quotations.
The field-based geotechnical, geochemical and environmental test work required for the PFS has been completed and lab-based studies are in progress. Other PFS tasks, including open pit mine design and tailings storage trade-off studies, are well advanced. Economic evaluation and cashflow modelling are in progress.
PFS report completion in the second quarter of 2024 is on schedule. Eleven mixed rare earth precipitate samples from the hydrometallurgical test work have been sent to potential partners, processors or end-users. Over the past 5 years, Defense Metals drilled 58 core holes totalling 12,073 metres (m; ~39,610 feet) to define the Wicheeda Rare Earth Element (REE) deposit and provide samples for metallurgical test work.
This work resulted in measured and indicated (M+I) resources of 34.2 million tonnes, averaging 2.02% TREO1, inclusive of 17.8 million tonnes of high-grade dolomite carbonatite averaging 2.92% TREO, in addition to inferred resources of 11.1 million tonnes, averaging 1.02% TREO. This represents a 260% increase over the Defense Metals initial 2019 mineral resource estimate, and a conversion to M+I of 101% of the prior 2021 mineral resource estimate. Total expenditures on the Wicheeda REE Project since 2019, including costs for mineral resource estimate definition, all metallurgical test work, earlier studies and the remaining PFS-related costs are in excess of CAD $17.5 million.
Defense Metals has entered into a strategic Co-Design Agreement with the McLeod Lake Indian Band (MLIB), the First Nations community having the traditional territory on which the Wicheeda Project sits. Extensive comminution, beneficiation, hydrometallurgical, and environmental tests have been completed and the resulting data have been applied in the PFS. These tests have studied development and optimization of milling and hydrometallurgical processes and the response of twenty-one variability samples representing different REE grades, lithologies and locations within the deposit.
From 2018 to date, about CAD$5 million has been spent on metallurgical test work and the development of the metallurgical flowsheets for the Wicheeda REE Project. Thirty-one samples of deposit material, flotation and hydrometallurgical products have been subjected to detailed mineralogical examination. Twenty-one samples have been subjected to Bond milling index and SMC comminution tests.
210 open circuit flotation tests and seven locked cycle flotation tests, of samples ranging from 1 to 12 kilograms (kg), and a 26-tonne pilot flotation operation have been completed. Sixty-three static acid bake tests, sixteen short-duration acid bake kiln runs with associated water leach tests were completed. Additionally, SGS completed a total of 15 days of continuous kiln operation (in one 5-day and one 10-day segment) as part of a fully integrated hydrometallurgical pilot plant operation that processed 560 kg of flotation concentrate.
Approximately 40 bench-scale impurity removal tests were done as well as about 40 rare earth precipitation tests and results incorporated in the integrated hydrometallurgical pilot plant operation and the project process design criteria. Many other small-scale tests examined water recycle options and other aspects of the metallurgical flowsheets. The liquid-solid separation characteristics of the flotation plant products and those of the hydrometallurgical plant have been determined through appropriate thickening and filtration tests.
Results from the metallurgical test work have been used to develop flowsheets for the planned comminution, beneficiation and hydrometallurgical plants. These flowsheets have been completed, reviewed and used to generate major equipment specifications for grinding mills, kilns, etc., which have been issued to equipment suppliers for quotes. The metallurgical process design, engineering and costing is on track to allow completion of the PFS in Second Quarter of 2024.
Optimization of Open Pit Mining Geotechnical investigation work for the mine design and pit optimization was performed by SRK and completed in December 2023. This work included sixteen geotechnical drill holes totaling 225.5 m, and twenty excavated overburden geotechnical test pits. Within the Wicheeda REE deposit pit shell, six diamond drill holes totaling 1,182 m were completed, inclusive of 4 open pit geotechnical drill holes totaling 920 m, and in-pit exploration holes totaling 262 m. Pit design work is underway, incorporating the latest geotechnical information provided from the 2023 geotechnical drilling program.
The Wicheeda REE Project has excellent infrastructure and logistics, which are expected to allow for lower operating and capital costs, including: · The future mine site and beneficiation plant will be located: · along a permitted Forest Service Road approximately 38 km east from the paved John Hart Provincial Highway at the community of Bear Lake. 37 km from the Canadian National Railway mainline. 36 km from the main natural gas distribution pipeline.
34 km from high-voltage powerlines that supply BC with abundant green hydroelectric power. 110 km from an international airport in Prince George British Columbia has a long history of mining and its industry participants are recognized worldwide as expert in open pit mining and mineral processing. Prince George is a major industrial center supplying both the mining and wood products industries.
Most of the equipment that will be required for the mining operation will be supplied by companies already established in the area. Multiple options exist for location of the hydrometallurgical plant site close to reagent supply. Easy access to the year-round port of Prince Rupert, the closest North American port to Asian markets.
