Premium Battery Grade 99.96% Spherical Graphite Purity Achieved For Lac Rainy Graphite Project In Quebec

Metals Australia Ltd (ASX:MLS) is very pleased to announce the achievement of 99.96% Cg spherical graphite purity, exceeding 99.95% Cg premium battery grade, in metallurgical test work on flake graphite concentrate from the Company’s high-grade Lac Rainy Graphite Project. Lac Rainy is situated in one of the world’s premier graphite regions in Quebec, Canada (see location, Figure 1).

Highlights

• Spherical graphite test work on concentrate from the Lac Rainy Graphite Project1 has achieved, above premium battery-grade, 99.96% spherical graphite carbon (Cg) purity.
• Very high-quality spherical graphite has been produced, that exceeds the specifications required by lithium-ion battery anode manufacturers globally, including:
  • Very high yield of 63.5% recovered into the 20-micron spherical graphite product, well in excess of the industry average yield of 40-50%2.
  • Consistent (very-steep) spherical graphite Particle Size Distribution (PSD) and spherical particle shape, after micronisation and spheroidization (see Image 1).
  • High Tap Density of 0.97 kg/litre (density or battery-anode packing qualities of spheroids in lithium-ion battery). Well above acceptable standard of 0.90 kg/litre.
• The Company has now commenced electrochemical (lithium-ion battery charging and durability) testing of the highly-purified spherical graphite material.
• Over 10 times the drilled strike-length of graphitic trends3 identified on the Project4. Immense potential for resource growth to be tested with new drilling program(s).

Chairman Mike Scivolo commented: “The achievement of premium battery grade spherical graphite purity, exceeding the specifications required by global lithium-ion battery manufacturers and using environmentally responsible, cost-effective methods - is an outstanding outcome for the Company.

“This places the Lac Rainy Project in the top tier of high-quality graphite projects, with an ideal location close to North American markets where demand for such high-quality graphite products is high.

“We will now rapidly advance the project towards development, in parallel with finalising electrochemical test work in Germany and advancing discussions with potential offtakers.”

Outstanding High-Purity Spherical Graphite Test Work Results:

The spherical graphite (SpG) test work was carried out by the specialist graphite testing group, ProGraphite, in Germany, on Lac Rainy flake graphite concentrate which was re-assayed, producing a higher concentrate grade of 96.3% Cg (Loss on Ignition - LOI) than the original assay at SGS in Canada¹.

The test work included three critical stages leading to the production of the high-quality, 99.96% Cg purified premium spherical graphite product. These included:

i) Micronisation (hammer milling) of the concentrate feed which achieved the targeted 20-micron (µm) average particle size with low energy input, producing very uniform micronised material suitable for spherical graphite production.

ii) Spheronisation of the micronised material using lower impact hammer milling, which produced:

• a very high recovery to spherical graphite product of 63.5% yield - well above industry average of 40-50% yield².
  
• Spherical graphite particles which have a steep (consistent) particle size distribution (PSD) and well-rounded spherical particle shape (see Image 1, below).
• Tap density (the packing qualities of spherical graphite particles into a lithium-ion battery anode) is high at 0.97 kg/litre. This is well above the industry standard of 0.90 kg/litre.

iii) Purification of the spherical graphite:

• Low-temperature alkaline (sodium hydroxide - NaOH) caustic roast with hydrochloric acid (HCl) achieved minimum saleable battery grade (>99.9% Cg) of 99.93% Cg SpG purity.
• The addition of a minimal HF wash finish resulted in the achievement of 99.96% Cg (LOI 800°C) premium battery-grade spherical graphite purity.
• This outstanding purity result was confirmed with Inductively Coupled Plasma (ICP) analysis, showing negligible levels of deleterious elements.

The premium battery grade purity and physical properties of the Lac Rainy spherical graphite product have exceeded the specifications required by lithium-ion battery anode manufacturers.

Electrochemical (battery charging and durability) testing of the high purity spherical graphite has commenced. This work will test the performance of the spherical graphite as an anode material in lithium- ion batteries and will involve multiple testing cycles designed to measure the discharge efficiency of the material (irreversible capacity loss) and its durability or specific capacity (driving battery life). ProGraphite has advised the Company that the electrochemical test work will take approximately 10 weeks.

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