Positive San Domingo Metallurgical Results
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Positive preliminary metallurgical results on samples from Jumbo Spodumene Pegmatite target at San Domingo Pegmatite District, Arizona
Bradda Head Lithium Ltd (AIM:BHL, TSX-V:BHLI, OTCQB:BHLIF), the North America-focused lithium development group, is pleased to announce positive metallurgical heavy liquid separation ("HLS") results from test work undertaken by the SGS Metallurgical Process Facility in Lakefield, Canada ("SGS Canada") on quartered drill core samples taken from its Jumbo Exploration Target at San Domingo District, Arizona, USA.
Overview
- Three composite samples were selected for test-work, representing the low grade, medium grade and high-grade environment reflected in the maiden 2022/2023 exploration programme previously reported from drilling undertaken at the Jumbo Target in the San Domingo Pegmatite district in Arizona.
- After discussion with SGS Canada, an initial HLS test was undertaken to evaluate the potential for dense media separation ("DMS") to produce a sellable Li-oxide concentrate product (see attached test work flowsheet). This test work is predominantly preliminary in its approach. The measured head grade of the samples were 3.05% Li2O, 1.03% Li2O and 0.34% Li2O, reflecting the high, medium and low-grade range seen in our drilling results to date.
- Despite the preliminary nature of this test-work programme, it was highly encouraging to see the medium-grade sample produce an 'in spec' lithium oxide concentrate product with a 6.0% Li2O grade and an interpolated recovery of contained lithium to the concentrate of 50.3%, at a ¼" size crush size. Tailings rejection was considered efficient in this scenario with the rejection of 60.6% mass and a loss of only 2.1% lithium.
- Alternately, at a crush size of 3/8" (9.5 mm), a concentrate was produced with a grade of 5.5 % Li2O at a 55.5% recovery of contained lithium oxide. This is still considered in spec in the current market. 'In spec' Li concentrate currently sells in the Lithium-Oxide Spot Market for circa US$2,100/ tonne.
- Using the medium-grade sample, the flotation feed, a combination of middling product from the HLS testing at a crush size of ¼" and under sized fraction (minus 0.85 mm), recorded an upgraded value of 1.57% Li2O with Li distribution of 47.0% and a mass distribution of 30.5%.
- At our request, SGS Canada also undertook Tescan Integrated Mineral Analyzer analysis of the medium grade sample, finding a dominance of spodumene as the primary lithium mineral with possible, but very minor petalite and eucryptite, along with muscovite, minor beryl, tourmaline, calcite, and apatite. The overall iron content is low, <1.0%, indicative of a very good concentrate product.
- Bradda is currently undertaking a second drilling programme at its San Domingo Pegmatite District with approximately 75% of the programme being complete. Assay results to date were released on November 12 2023, highlighted by drill hole SD-DH23-049 which contains 6.35m @ 0.83% Li2O followed by 3.05m @ 1.03% Li2O, with more results arriving in the near future.
- Metallurgical test work is now currently on hold whilst Bradda collects more representative samples from this next phase of drilling to undertake a more detailed test work programme.
Bradda has 33km2 license area under its control within this exciting pegmatite district. It is a historical lithium mining environment with over 7 historic mines that focused on shallow open pit extraction of spodumene during the late 1940s and early 1950s. Bradda commenced drilling in H2 of 2022 (7,300m) and is on its second campaign of 6,100 meters of core drilling, designed to expand on existing mineralized intercepts and drill-test newly developed high-quality lithium in pegmatite targets derived from soil sampling and surface mapping.
Diamond core drilling continues at the San Domingo Pegmatite project with approximately 75% of the program completed, where many of the holes have encountered long intervals of pegmatite with visible spodumene mineralization. Assay results have been slow to arrive due to the summer rush at the laboratory, but drilling progress is good. Additional permits were received from the State and BLM, sites are being constructed at the historic Morning Star lithium mine and drilling there is planned to commence shortly. The Company hopes to have news on San Domingo within the next few weeks as preliminary results have started to arrive.
Ian Stalker, Executive Chairman, commented:
"These results are highly encouraging, and quite simply better than expected from what can only be described as preliminary non-detailed scoping test work. To produce an 'in spec' sellable gravity concentrate reflecting over 50% recovery to the concentrate from a sample grading 1.03% Li2O on first pass test work is simply mouth watering. Gravity Concentration, in this case, otherwise referred to as dense media separation, is a standard, low cost, simple process with a small, relatively non-invasive foot print.
"It is the kind of process operation that is quick to design and install, and yet can deliver very attractive economic returns. We are therefore highly encouraged, and when the next phase of drilling at San Domingo is complete and sufficient sample material is available, we will revert quickly to SGS with a more detailed test work and study programme to further the above objective."
Independent Qualified Person (SGS)
The technical content relating to metallurgical testing disclosed in this document was reviewed and approved by Curtis Mohns, P.Eng., Senior Metallurgist at SGS Canada. Mr. Mohns has an M.Sc. in Mineral Processing Engineering and 29 years of related professional experience. Mr. Mohns is a Qualified Person as defined under NI 43-101.
About Bradda Head Lithium Ltd.
The Basin East Project has an Indicated Mineral Resource of 17 Mt at an average grade of 940 ppm Li and 3.4% K for a total of 85 kt Lithium Carbonate Equivalent ("LCE") and an Inferred Mineral Resource of 210 Mt at an average grade of 900 ppm Li and 2.8% K (potassium) for a total of 1.0 Mt LCE. In the rest of the Basin Project, SRK has determined an Exploration Target of 250 to 830 Mt of material grading between 750 to 900 ppm Li, which is equivalent to a range of between 1 to 4 Mt contained LCE. The Group intends to continue to develop its three phase one projects in Arizona, whilst endeavouring to unlock value at its other prospective pegmatite and brine assets in Arizona, Nevada, and Pennsylvania. All of Bradda Head's licences are held on a 100% equity basis and are in close proximity to the required infrastructure. Bradda Head is quoted on the AIM of the London Stock Exchange with the ticker of BHL, on the TSX Venture Exchange with a ticker of BHLI, and on the US OTCQB market with a ticker of BHLIF.
Technical Glossary
| Li 2 O | Lithium Oxide |
| pegmatite | A pegmatite is an igneous rock showing a very coarse texture, with large interlocking crystals usually greater in size than 1 cm (0.4 in) and sometimes greater than 1 meter (3 ft). Most pegmatites are composed of quartz, feldspar, and mica, having a similar silicic composition to granite. However, rarer intermediate composition and mafic pegmatites are known. |
| Spodumene | Spodumene is a pyroxene mineral consisting of lithium aluminium inosilicate, LiAl(SiO 3 ) 2 , and is a source of lithium. Spodumene contains 3.73% lithium. |
| Lepidolite | Lepidolite is a lilac-gray or rose-colored member of the mica group of minerals with chemical formula K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2.[2][3] It is the most abundant lithium-bearing mineral[4] and is a secondary source of this metal. It is the major source of the alkali metal rubidium. Lepidolite contains 3.58% lithium. |
The formula to convert lithium in parts per million (PPM) to lithium oxide is to multiply Li ppm times 2.1527, then is reported in percent.
| Kt | Thousand tonnes |
| Ppm | Parts per million |
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