Mr. Craig Taylor reports
DEFENSE METALS PRE-PILOT HYDROMETALLURGY TESTING YIELDS 97.3% RARE EARTH ELEMENT EXTRACTION FROM WICHEEDA FLOTATION CONCENTRATE
Defense Metals Corp. has received additional prepilot hydrometallurgical test work utilizing high-grade rare earth element (REE) mineral concentrate produced during Defense Metals' highly successful 26-tonne flotation pilot plant that yielded a mineral
concentrate averaging 7.4 per cent NdPr oxide (neodymium-praseodymium) (1).
The road-accessible Wicheeda REE property is located close to infrastructure approximately 80 kilometres northeast of Prince George, B.C. The Wicheeda project has indicated mineral resources of 4.89 million tonnes averaging 3.02 per cent LREO (light rare earth elements) and inferred mineral resources of 12.1 million tonnes averaging 2.90 per cent LREO (2).
Highlights of the additional infill hydrometallurgical test results conducted at SGS Canada Inc. Lakefield site are as follows:
Increased REE extraction from 91.5 per cent to 97.3 per cent from flotation concentrate (about 75 per cent from bulk sample feed) into a chloride-based leach solution compared with initial testing (3) (CC-21, see attached table);
Decreased REE losses via milder gangue leach compared with the base case flowsheet (3);
Simplification of flowsheet by removing regrind step and reducing caustic dosage on recrack (CC-20) yielded comparable REE extraction of 95.8 per cent from flotation concentrate (about 74 per cent from bulk sample feed).
Craig Taylor, chief executive officer of Defense Metals, stated: "Our decision to conduct additional infill hydrometallurgical test work has yielded significant REE recovery gains approaching 100-per-cent REE extraction from the flotation concentrate. Perhaps more importantly, this additional testing has advanced the Wicheeda REE separation flowsheet such that we able to 'tune' process variables (chiefly: grind size, acid and caustic concentrations) to achieve a balance of minimizing REE leach losses and maximizing impurity removal. This level of process control will derisk our planned hydrometallurgical pilot plant and contribute to greater flexibility in design of a future commercial-scale hydrometallurgical plant."
(1) See Defense Metals news release dated Sept. 23, 2020.
(2) Technical report on the Wicheeda property, British Columbia, effective June 27, 2020, and prepared by APEX Geoscience Ltd. (Steven J. Nicholls, BASc, MAIG, and Kristopher J. Raffle, BSc, PGeo) is available under Defense Metals' profile on SEDAR.
(3) See Defense Metals news release dated Feb. 18, 2020.
COMPARISON OF 2019/2020 AND 2021 HYDROMETALLURGICAL ND RECOVERIES
Stage Recovery from Nd recovery
Initial bench program (2019-2020) extraction (Nd) bulk sample feed from conc.
Flotation conc. 86% 85.7% 100%
Gangue leach 8%
Caustic crack 1 100%
Acid leach 1 91% 71.7% 83.7%
Caustic crack 2 100%
Acid leach 2 86% 77.8% 91.5%
Second bench program (2020-2021) Stage Recovery from Nd recovery
CC21 data set extraction (Nd) bulk sample feed from conc.
Flotation conc. 77% 77.3% 100%
Gangue leach 0%
Caustic crack 1 0%
Acid Leach 1 89% 68.6% 88.7%
Caustic Crack 2 0%
Acid Leach 2 76% 75.2% 97.3%
About the Wicheeda REE property
The 1,708-hectare Wicheeda REE property, located approximately 80 km northeast of the city of Prince George, B.C., is readily accessible by all-weather gravel roads and is nearby to infrastructure, including power transmission lines, the CN railway and major highways.
Geologically, the property is situated in the Foreland belt and within the Rocky Mountain Trench, a major continental geologic feature. The Foreland belt contains part of a large alkaline igneous province, stretching from the Canadian Cordillera to the southwestern United States, which includes several carbonatite and alkaline intrusive complexes hosting the Aley (niobium), Rock Canyon (REE) and Wicheeda (REE) deposits.
The scientific and technical information contained in this news release as it relates to the Wicheeda REE property has been reviewed and approved by Kristopher J. Raffle, PGeo (B.C.), principal and consultant of APEX Geoscience Ltd. of Edmonton, Alta., a director of Defense Metals and a qualified person as defined in National Instrument 43-101 -- Standards of Disclosure
for Mineral Projects. Mr. Raffle verified the data disclosed which includes a review of the analytical and test data underlying the information and opinions contained therein.
Methodology and quality assurance/quality control
Hydrometallurgical product assays for neodymium was determined via lithium-borate fusion of a 0.5-gram sample analyzed via wavelength dispersion X-ray fluorescence (WD-XRF). The remaining rare earth elements for the head sample were determined via 0.5-gram sodium-peroxide fusion multielement ICP-MS.
The SGS analyses included a quality assurance/quality control (QA/QC) program including the insertion of rare earth element standard and blank samples. Defense Metals detected no significant QA/QC issues during review of the data. Defense Metals is not aware of any drilling, sampling, recovery or other factors that could materially affect the accuracy or reliability of the data referred to herein. SGS is an ISO/IEC 17025 and ISO9001:2015 accredited laboratory. SGS is independent of Defense Metals and the qualified person.
Defense Metals Corp.
Defense Metals is a mineral exploration company focused on the acquisition of mineral deposits containing metals and elements commonly used in the electric power market, military, national security and the production of green energy technologies, such as high strength alloys and rare earth magnets. Defense Metals has an option to acquire 100 per cent of the 1,708-hectare Wicheeda rare earth element property located near Prince George, B.C., Canada.
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