STSBF - South Star Mining Corp. Announces Positive Purification Results from Its Advanced Graphite Battery Metals and Technology Testing Program
(TheNewswire)
Toronto, ON - TheNewswire - May 20, 2021 - SouthStar Mining Corp. ( “South Star ” or the “Company” ) (TSXV: STS ) (OTCQB:STSBF) is pleased toannounce the positive purification results usinga thermal process from its advanced testing program with itstechnology partner, the United States laboratory (“USLab”) 1 . Thermal purification is a proven,commercially-viable technology for improving the quality ofconcentrate graphite for a broad range of value-add applications,including lithium-ion batteries (“LiB”). It also represents acompelling alternative to purification by acid leaching withhydrofluoric acid, that is the most common practice in use today.
Richard Pearce, President and CEO ofSouth Star , commented: “We are pleased toannounce these exciting results. The thermal purification process hasresulted in 99.9993 wt% C without any of the environmental, health andworker safety issues associated with hydrofluoric acid. Yet anotherindustry specialist has indicated that the Santa Cruz graphiteconcentrate is one of the best materials they have analyzed and farexceeds typical industry standards. The results highlight thehigh-quality, high-purity and low-contaminate nature of South Star’sconcentrates and purified graphite. The offtake agreements we recentlyannounced highlight the improving market conditions and reinforce theCompany’s market opportunity.
We will be able to offer an extremely high-qualityproduct to a broad array of possible markets and sectors. The ore isgenerally easy to concentrate and purify and will allow us to sell ourentire production at attractive margins. As part of the scope of theongoing advanced testing program, South Star will continue to improveour understanding of the inherent material characteristics, and thenset up a commercial plan that maximizes our pricing and profits acrossthe entire basket of products. The testing program is now advancingtowards production of the battery-grade coated spherical graphite(cSPG).
We are quickly building South Star into the first newgraphite operation in continuous commercial production in the Americasin more than a decade.”
1 The United States laboratory (“USLab”) specializes in advanced graphite materials and value-addtesting for battery and non-battery applications. The US Lab companyname has not been published for the purposes of preserving acommercial advantage of South Star Mining in the marketplace.
Flake graphite concentrate from the Santa Cruz GraphiteProject (the “Project” or “Santa Cruz”) with an average carboncontent of 95.3 wt% and moisture level of 0.075 wt%, was upgraded to99.9993 wt% C, which are excellent results suitable for a broad rangeof LiB and value-add applications. In addition, the results indicateextremely pure graphitic carbon with high-yields, low-levels ofcontaminants and ease of upgrading.
In particular, aluminum, boron, iron, sulfur, andsilicon were at extremely low-levels and well-below standard industryrequirements. The ease with which impurities were removed from thecarbon structure also suggests that the Santa Cruz graphitepredominantly contains impurities concentrated on the surface of itsparticles as opposed to being intercalated in the form of gangueinside the flake graphite macromolecules.
With these excellent results, purified graphite fromthe Project has successfully demonstrated to possess a puritysignificantly greater than that required for typical applications inadvanced battery systems, where the normal criteria are in the orderof 99.95-99.98 wt% C. The results also reinforce that purifiedgraphite from the Project is suitable for other high value-addapplications that require very-high levels of purity with low-levelsof contaminants, such as nuclear. Typical market pricing for theseproducts can range from between US$25,000-US$40,000 per tonne.
The Company also wishes to report on the favourableremoval of some high-value elements present in mineral ash, that isthe waste by-product of the purification process. The elements cangenerally be subdivided into precious metals and rare earth elements.The first group in the case of Santa Cruz contained appreciableamounts of the precious metals, such as silver, gold, palladium, andplatinum. The second group, rare earth elements, contained the notableconcentrations of the following: scandium, yttrium, lanthanum, cerium,praseodymium, neodymium, samarium, europium. South Star will publishresults of these studies in a separate news release when finalized. Itshould be noted that as a result of purification, all these elementsalong with other mineral impurities have been successfully evaporatedoff the graphite surface and transferred into the wet scrubber wherethey were concentrated back in the gypsum by-product of off-gastreatment.
Detailed Test Results
South Star used its concentrate grade purity graphite,which had total graphitic carbon content of 95.3 wt%, moisture levelof 0.075 wt%, and particle size distribution as depicted by the bluebars in Figure 1 . As the graphic shows, the distribution of Santa Cruzconcentrate consists approximately of three equal proportions: thefirst representing +50 to +30 mesh flake, followed by +100 to +60mesh, and finally -100 mesh. The same graph shows particle sizedistribution by screen analysis of thermally purified materialrepresented as the orange bars in Figure 1 . As one can see, purification didnot cause a change in particle size distribution, which cannot beexplained by differences in screening, meaning that no significantdamage to the graphite particles occurred during the process.
Figure 1 . Particle sizedistribution of concentrate grade (blue) and purified (orange)
South Star graphite, obtained by screen analysis.
The surface area of South Star’s concentrate gradegraphite was shown to be reduced by purification. Figure 2 showssurface area decreasing from 3.83 m 2 /g inconcentrate grade material to 2.41 m 2 /g after thermalpurification. This is indicative that fine mineral impuritiesrepresenting submicron particles with high surface area have beenremoved from the purified graphite product.
Figure 2 . Surface area[m 2 /g] of South Star Mining Corp.’s graphite before
(concentrate grade) and after thermal purification.
Table 1 . Mineral impurities ofconcentrate grade and purified
South Star graphite obtained by Solid ICP.
Furthermore, Table 1 compares elemental mineral-impurityconcentrations before and after purification. The data presented aredeveloped by method of solid ICP, which is known for its high accuracyin determining mineral impurities to ppm concentrations, withouthaving to perform acid digestion of the graphite sample. Instead, thedry sample is analyzed as-is and is consumed entirely in the course ofanalysis. This method is believed to be more accurate than classic ICPby acid digestion and provides a comparable result to that of theindustry premium GDMS method .
We highlight the following notable observationsproduced by solid ICP analysis: aluminum concentration was reduced byfive orders of magnitude while silicon concentration was reduced byfour orders of magnitude. Iron concentration also decreased fiveorders of magnitude from 10,000 ppm (1 wt.%) to the level of 0.63 ppm,an extremely low value for iron concentration in the industry.Finally, sulfur decreased from 49 ppm in the precursor to 0.344 ppm inthe purified product. The ease with which impurities were removed fromthe carbon structure suggests that Santa Cruz graphite predominantlycontains impurities concentrated on the surface of its particles asopposed to being intercalated in the form of gangue inside the flakegraphite macromolecules.
The purity of South Star’s material was measuredusing the industry-standard loss-on-ignition test. In accordance withthis test, a known mass of graphite is placed in either an aluminumceramic crucible or a platinum crucible and is heat treated in amuffle furnace at 950?C for a specific amount of time. This resultsin complete evaporation of all carbon, while any materials left behindare attributed to ash content. While the concentrate grade precursorto thermal purification had average purity of 95 wt% C, the purity ofgraphite after thermal purification as measured in aluminum cruciblesexceeded that of 100%, indicating that a ceramiccrucible method did not impart the desired level of accuracy todetermine purity. The same test was repeated in a platinum cruciblewith a larger sample mass, and this produced a purity result of99.9993 wt% C. The change in purity can be visualized in Figure 3 , while therelated moisture content is shown for reference in Figure 4 .
With these results, purified Santa Cruz graphite hasbeen demonstrated to possess a purity significantly greater than thatrequired for applications in advanced battery systems. It is believedthat the passing criterion for the latter market is 99.95-99.98 wt% C.The LOI result suggests that Santa Cruz graphite can be qualified asnuclear-grade graphite based on its LOI purity and judging from theconcentration of boron in its structure. Nuclear grade graphites,which range in their sales pricing between US$25,000-$40,000 per tonnemust meet certain criteria, which includes purity of 99.99 wt% C and aconcentration of boron less than 2 ppm. In the case of Santa Cruzgraphite, even the concentrate grade material had anaturally-occurring extremely-low concentration of boron at 1.8 ppm,that is seldom seen in the natural graphite industry for concentrategrade material. After purification, the concentration of boron wasreduced to 0.43 ppm, and this change is visualized in Figure 5 .
The resultant particles with a purity of 99.9993 wt% Care depicted in Figure6 to Figure 11 by a series of scanning electronmicroscope images at various mesh cuts. The images show +35, +50, +70,+100, +200, and +325 cuts.
| Figure 6 . SEM image of +35 mesh thermally purified SouthStar graphite, at a magnification of x45. |
| Figure 7 . SEM image of +50 mesh thermally purified SouthStar graphite, at a magnification of x150. |
About South Star Mining Corp.
South Star Mining Corp. is focused on the selectiveacquisition and development of near-term production projects inBrazil. South Star is driven to create fundamental value in thebattery metals sector for clients and investors with real projectsthat have strong intrinsic financial and operating metrics, and thatcan be profitable throughout the resource cycle. South Star has anexperienced executive team with a strong history of discovering,developing, building and operating profitable mines in Brazil.
The Santa Cruz Graphite Project, located in SouthernBahia, is the first of a series of battery metals projects that willbe put into production. Brazil is the second-largestgraphite-producing region in the world with more than 80 years ofcontinuous mining. The Project has at-surface mineralization infriable materials, and successful large-scale pilot-plant testing(>30t) has been completed. The results of the testing show thatapproximately 65% of Cg concentrate is +80 mesh with good recoveriesand 95-99% Cg. With excellent infrastructure andlogistics, South Star is carrying its development plan towards Phase 1production projected in Q4 2022, pending financing.
The Santa Cruz project is being developed in a phasedapproach. Phase 1 operations for the 5,000 tpy pilot plantoperations are fully licensed, and the Company is preparing to startconstruction in September 2021 with commercial production targeted forQ4 2022. Phase 2 operations will represent a larger-scaleconcentration plant currently planned to produce between 25,000 to30,000 tpy of concentrate. The sizing of the Phase 2 plant could beincreased depending on the successes of the Phase 1 operations,ongoing development of commercial relationships, and marketconditions.
South Star is committed to a corporate culture, projectexecution plan and safe operations that embrace the highest standardsof ESG principles based on transparency, stakeholder engagement,ongoing education and stewardship. To learnmore, please visit the Company website at http://www.southstarmining.ca .
On behalf of the Board,
Mr. Richard Pearce
Chief Executive Officer
For additional information, pleasecontact:
CHF Capital Markets
Iryna Zheliasko, Manager
Phone: 416-868-1079 x229
Email: iryna@chfir.com
Mr. Dave McMillan
Chairman
Email: davemc@telus.net
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CAUTIONARY STATEMENT
Neither the TSX Venture Exchange norits Regulation Services Provider (as that term is defined in policiesof the TSX Venture Exchange) accepts responsibility for the adequacyor accuracy of this press release.
This news release and the UpdatedTechnical Report contain references to inferred resources. The Reportis preliminary in nature and includes inferred mineral resources thatare considered too speculative geologically to have the economicconsiderations applied to them that would enable them to becategorized as mineral reserves.
Forward-Looking Information
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