31 Oct 2019 14:06
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Alba Mineral Resources plc
("Alba" or the "Company")
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Amitsoq Processing Testwork Achieves
High-Grade, Premium-Flake Product
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Alba Mineral Resources plc (AIM: ALBA), the diversified mineral exploration and development company, is pleased to announceΒ that it has completed a Phase 2 metallurgical testwork programme in respect of the Company's exceptionally high-grade Amitsoq graphite project in southern Greenland. This programme has confirmed that Amitsoq graphite is amenable to the production of a high-grade refined product and that a significant proportion of the flake graphite in the product comprises larger-sized flake graphite which attracts premium prices.
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Highlights
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Β·; Building on prior results, this round of testing confirms that a saleable (97.3% TGC) product can be produced from Amitsoq graphite.
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Β·; The Phase 2 testwork programme has been designed to maximise the level of high-value flake graphite in the refined product.
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Β·; Image analysis shows that 36% of the refined product consists of large, jumbo and super jumbo flake sizes, which attract a premium price in the graphite market.
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Β·; This is a very positive and potentially very significant result, as it indicates that higher-value flake graphite will be among the products that may be produced from Amitsoq graphite, which will greatly assist in the development of a positive technical economic model for the project.
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Β·; Alba will now move on to the design of a further phase of refining testwork.
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George Frangeskides, Alba Executive Chairman, commented: "This completed Phase 2 test programme for our exceptionally high-grade graphite project at Amitsoq confirms two very important things. Firstly, that a saleable, 97.3% product can be produced. And secondly, that in that refined product is included a significant proportion of the higher-value flake graphite that is sought-after for a range of industrial uses, which still underpin the majority of the demand for natural flake graphite globally. This will be very important for the future economics of the Amitsoq Project."
"We will build on this latest phase of work with further refining testwork, and also to assess the amenability of Amitsoq graphite to produce a very high purity product suitable for the battery metals sector."
"This completed work on one of our key assets provides us with great confidence as we move into 2020."
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Introduction
Alba contracted process metallurgical consultants SouthernΒ CrossΒ MiningΒ Limited ("SCM")Β toΒ designΒ and superviseΒ aΒ mineralogyΒ andΒ process studyΒ onΒ theΒ AmitsoqΒ andΒ KalaaqΒ graphiteΒ depositsΒ inΒ southern GreenlandΒ and to reportΒ onΒ theΒ findings. TheΒ primaryΒ objectiveΒ of theΒ study was toΒ recoverΒ aΒ highΒ purity graphiteΒ productΒ with aΒ focus onΒ preservingΒ graphiteΒ flakeΒ size.Β TheΒ testwork included the following technical components:
1) Microscopic analysisΒ of resin-mountedΒ samplesΒ andΒ flotation feed,Β concentrateΒ andΒ tailings.
2) Bench-scaleΒ batchΒ rougherΒ andΒ cleanerΒ flotationΒ tests.
3) HydrometallurgicalΒ refiningΒ ofΒ the flotationΒ final concentrate.
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The Phase 2 programme wasΒ carried out onΒ 25 kg ofΒ channel samplesΒ taken fromΒ theΒ UpperΒ GraphiteΒ BedΒ ("UBA") and Lower GraphiteΒ BedΒ ("LBA")Β atΒ Amitsoq, as well as fromΒ the LowerΒ GraphiteΒ Bed at Kalaaq ("LBK"). See Figure 1 in the PDF version of this announcement for the Project location.Β
TheΒ samplesΒ were submittedΒ toΒ mineralogy and petrology specialists Petrolab (Cornwall, UK), for crushingΒ andΒ preparationΒ of resin-impregnatedΒ blocksΒ and slides, which were then submitted forΒ petrographic analysis toΒ MSAΒ Global, a specialist South African firm.
TheΒ balance of the channel samples wereΒ submittedΒ toΒ Geolabs GlobalΒ Limited, a metallurgical and mineralogical laboratory in South Africa,Β for beneficiationΒ andΒ refining. Bench-scaleΒ flotationΒ trialsΒ wereΒ conducted inΒ conjunctionΒ with stereomicroscopic analysisΒ of flotationΒ productΒ streams. The finalΒ flotationΒ concentrateΒ wasΒ then submitted forΒ acidΒ leachingΒ asΒ a proofΒ ofΒ conceptΒ forΒ hydrometallurgical refiningΒ toΒ reach theΒ final Total Graphitic CarbonΒ ("TGC")Β grade.
TheΒ mainΒ objectivesΒ of this programmeΒ were to maximiseΒ theΒ final product gradeΒ andΒ flakeΒ size, and to identifyΒ aΒ possibleΒ processΒ flowsheetΒ forΒ coarse-flake graphiteΒ recovery. The programme was split into four phases: petrographic analysis; flotation tests; purification of final concentrate; and determination of flake-size distribution in final concentrate.
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First Stage Testwork: Petrographic Analysis
IdentificationΒ ofΒ spatialΒ variations in graphiteΒ andΒ gangue mineral characteristicsΒ wasΒ achievedΒ via petrographic analysisΒ of resin-mounted blocksΒ andΒ thinΒ sections. ReflectiveΒ andΒ transmissiveΒ light microscopyΒ wereΒ usedΒ to estimateΒ grindΒ sizesΒ requiredΒ for initial flotationΒ trialsΒ based onΒ theΒ observed graphiteΒ flakeΒ sizes andΒ degreeΒ of gangueΒ mineral interlocking. A briefΒ summaryΒ of theΒ findings isΒ set out in Table 1 below.
Table 1: Summary of petrographic analysis of resin-mounted blocks and thin sections
Sample Description | Max flake length (Β΅m) | Ave. Flake Size (Β΅m) Estimate (Β΅m) | Gangue Mineral Association |
Lower Bed, Kalaaq | 820 | 278 | Often interlocking |
Upper Bed, Amitsoq | 1230 | 440 | Very minor interlocking |
Lower Bed, Amitsoq | 1270 | 472 | Very minor interlocking |
Lower Bed, Amitsoq | 1550 | 513 | Minor interlocking |
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This testwork programme was focused on the Amitsoq material. KalaaqΒ material will be the subject of a future testwork programme.
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Second Stage Testwork: Flotation Tests
ToΒ concentrateΒ coarse-flakeΒ graphite,Β graphiteΒ from both the upperΒ andΒ lowerΒ beds at Amitsoq was subjectedΒ toΒ aΒ seriesΒ ofΒ flotationΒ sighterΒ testsΒ toΒ scopeΒ potential processΒ flowsheets suitableΒ for producing a finalΒ graphiteΒ product. BasedΒ on stereoscopicΒ observations, mass distributionΒ and total graphitic carbon ("TGC")Β assayΒ data,Β a combinationΒ of flotation, re-crushingΒ andΒ leachingΒ stepsΒ were selected. Collectively,Β theseΒ steps canΒ beΒ summarised inΒ aΒ conceptual processΒ flowsheetΒ as set out in Figure 2 of the PDF version of this announcement.
RougherΒ flotationΒ wasΒ usedΒ toΒ generateΒ aΒ crudeΒ concentrate withΒ severalΒ subsequentΒ stages ofΒ cleaner andΒ recleanerΒ flotationΒ toΒ selectivelyΒ recoverΒ liberated graphite.Β StereomicroscopyΒ gaveΒ insightΒ into the degreeΒ of liberation,Β approximateΒ mineral abundanceΒ andΒ mineral associationΒ to guideΒ subsequent cleaningΒ andΒ size reductionΒ steps. Final refiningΒ byΒ leaching was employed to meetΒ theΒ targetΒ TGCΒ grade withoutΒ overgrindingΒ ofΒ coarse graphite.Β TheΒ mainΒ findings of thisΒ sectionΒ of theΒ workΒ areΒ asΒ follows:
(a) FlotationΒ parametersΒ wereΒ selectedΒ from petrographicΒ observations and yieldedΒ the results inΒ Table 2 below.
Β Table 2: Two-Stage Rougher Flotation Results
Location | Upper Bed Amitsoq ("UBA") | Lower Bed Amitsoq ("LBA") | Lower Bed Kalaaq ("LBK") |
pH | 9 | 9 | 9 |
Initial Crush Size (mm) | 1.7 | 1.7 | 1 |
First Rougher Recovery | 85.8% | 81.4% | 82.8% |
Second Crush Size (mm) | 0.6 | N/A | N/A |
Total Recovery | 98.4% | 85.6% | 82.8% |
Total Mass Rejection | 27.8% | 47.1% | 40.9% |
(b) TheΒ bestΒ cleaningΒ results wereΒ obtained by sixΒ stagesΒ ofΒ cleaning, followedΒ byΒ crushingΒ and recleaningΒ theΒ cleanerΒ tailings.Β Results forΒ thisΒ methodΒ areΒ summarisedΒ inΒ Table 3.
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Table 3: Cleaner and Recleaner Results
pH | 9.5 |
Cleaner Feed Size (P80, mm) | 0.71 |
Cleaner Recovery | 58.6% |
Re-Cleaner Feed Size (P80, mm) | 0.3 |
Total Recovery | 85.3% |
Final Flotation Conc. grade | 53.9% |
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Third Stage Testwork: Purification of Final Concentrate
PurificationΒ ofΒ theΒ final flotationΒ concentrateΒ was conductedΒ usingΒ a two-stageΒ acidΒ leach toΒ remove gangue material.Β TheΒ mainΒ advantageΒ ofΒ hydrometallurgical refiningΒ is thatΒ chemical separationΒ of gangueΒ doesΒ notΒ require completeΒ physical departureΒ of graphiteΒ fromΒ gangue. TheΒ finalΒ graphiteΒ grade achievedΒ afterΒ leachingΒ was 97.3%Β TGC,Β asΒ listedΒ in Table 4 below.
Table 4: Gangue Leach Results
1st Stage (HF) Mass Loss | 33.2% |
1st Stage (HF) TGC Grade | 82.1% |
2nd Stage (HF) Mass Loss | 8.1% |
2nd Stage (HF) TGC grade | 97.3% |
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Fourth Stage Testwork: Determination of Flake-Size Distribution
In order to ascertain the flake-size distribution of the final concentrate, aΒ combinationΒ of imageΒ analysisΒ onΒ theΒ coarse fractionΒ suspended inΒ acetoneΒ andΒ screening onΒ theΒ fineΒ fractionΒ wasΒ selected.Β TheΒ results are set out in Table 5 below (see also Figure 3 in the PDF version of this announcement). These results indicate that 36% of the flake size is in the Large, Jumbo and Super-Jumbo categories, which attract premium prices in the graphite market.
Table 5: Results of flake-size distribution analysis on final concentrate
FLAKE LENGTH IMAGE ANALYSIS | |||
Category | Min. Size | Mass % | Cum. Mass % |
Super Jumbo | 500 | 7 | 7 |
Jumbo | 300 | 14 | 21 |
Large | 180 | 15 | 36 |
Medium | 150 | 1 | 37 |
Small | 75 | 24 | 61 |
Fine | -75 | 39 | 100 |
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The Graphite Market: Outlook, Products and Pricing
To understand the significance of these Phase 2 test results, it is important to put them in the context of the global graphite market and the demand for different graphite products.
Forms of graphite
Graphite comes in different forms and specifications. The two main forms are natural graphite, which is sourced directly from mines, and synthetic graphite, which is made from petroleum coke. In turn, there are three main types of natural graphite: flake (>85% carbon), amorphous (60-85% carbon) and vein (>90% carbon).
Size is also an important factor when it comes to natural graphite. Flake size comes in the following categories: Super Jumbo (+500 microns), Jumbo (+300 microns), Large (+180 microns), Medium (+150 microns) and Small or Fine (-150 microns). For industrial uses, Jumbo and Large flake are preferred, such as in blast furnace steel making, castings and lubricants. In nuclear applications, Super Jumbo flakes are used (Argus Media publication, Getting Graphite Prices Right, 2019).
However, flake size is less relevant for high purity battery grade applications as the graphite is micronized to less than 30 micron prior to shaping and purification. As a result, typically only lower-cost small and medium flake sizes or fines are used in the production of spherical graphite for battery production (Argus Media, as above).
Production of marketable flake graphite products
Mined graphite ore is first beneficiated into graphite concentrate (typically 94-97% TGC) and then sized and screened into various sizes. Flake prices are then determined based on a range of factors such as graphite content, flake size and impurity levels. Large, Jumbo and Super Jumbo flake with a higher purity (94% or higher carbon content) command premium prices. Small or fine flake graphite is reported to currently command a price of around US$400 per tonne, Large flake US$1000 per tonne, Jumbo flake US$1400 per tonne and Super Jumbo flake US$2000 per tonne (per www.stockhead.com.au, 16 September 2019, quoting Roskill).
The fact that Large, Jumbo and Super Jumbo flake can attract significantly higher prices, and that 36% of the flake within the refined product produced from Amitsoq in the current test programme is made up of those higher-value flake categories, is considered of potentially real significance for the future economics of the Amitsoq project.
Production of High Purity Spherical Graphite for the battery metals sector
According to Roskill, current global graphite demand is accounted for by the following product markets: electrodes (30%), refractories (18%), recarburising (12%), batteries (10%), lubricants (7%), foundries (6%), other (17%). However, Roskill have forecast that by 2029 batteries will account for 26% of the global demand for graphite. (Roskill, "Battery and electric vehicle raw materials insights" presentation, London, 29 October 2019).
To meet battery cell manufacturers' specifications for use as the anode in lithium ion batteries, the natural flake graphite must be purified and shaped into small spheres, at which point the material is referred to a High Purity Spherical Graphite ("HPSG"). After shaping, the natural flake graphite is purified by chemical leaching to remove impurities and raise the carbon content to above 99.95% C. HPSG is further processed by coating a single layer of carbon onto the spheres to produce spherical coated graphite. (www.leadingedgematerials.com)
According to Roskill, flake graphite concentrate typically commands a price of $650-850/t, whereas uncoated spherical graphite commands $3000-4000/t and coated spherical commands +$7000/t. (Roskill presentation, 29 October 2019, as above). Given the significant premium attaching to spherical graphite products, the Company intends to include in a future work stream testwork to assess the amenability of Amitsoq and Kalaaq graphite to produce HPSG.
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Recommendations for Further Work
Recommendations for furtherΒ metallurgical process work and economic studies include the following:
(1) TailoringΒ of processΒ testwork toΒ meet the requirementsΒ of potential concentrateΒ offtakeΒ customers and currentΒ marketΒ demands.
(2) Economic cost-benefit analysis betweenΒ flakeΒ size,Β final floatΒ concentrateΒ gradeΒ andΒ refiningΒ costs.
(3) Separate testwork stream to ascertain the amenability of Amitsoq and Kalaaq graphite for the production of spherical graphite.
The information contained within this announcement is deemed by the Company to constitute inside information under the Market Abuse Regulation (EU) No. 596/2014.
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Forward Looking Statements
This announcement contains forward-looking statements relating to expected or anticipated future events and anticipated results that are forward-looking in nature and, as a result, are subject to certain risks and uncertainties, such as general economic, market and business conditions, competition for qualified staff, the regulatory process and actions, technical issues, new legislation, uncertainties resulting from potential delays or changes in plans, uncertainties resulting from working in a new political jurisdiction, uncertainties regarding the results of exploration, uncertainties regarding the timing and granting of prospecting rights, uncertainties regarding the Company's or any third party's ability to execute and implement future plans, and the occurrence of unexpected events. Actual results achieved may vary from the information provided herein as a result of numerous known and unknown risks and uncertainties and other factors.
Competent Person's Declaration
Michael Nott, who has over 45 years' relevant experience in the geological, mining, minerals, waste disposal, industrial minerals, oil, drilling, mineral planning and quarrying industries, has approved the technical information in this announcement.
Mr Nott holds a BSc. degree in Geology from Queen Mary, University of London, a MSc. Degree in Mineral Production Management from the Royal School of Mines, Imperial College, University of London, The Diploma of Imperial College in Mineral Production Management and is a Chartered Engineer. He is a Fellow of the Institute of Materials, Minerals and Mining, a Fellow of the Minerals Engineering Society, a Fellow of the Institute of Quarrying and an Associate of the Royal School of Mines Association.
Glossary
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Acid leaching | Metallurgical process for dissolution of metals by means of acid solution. |
Bench-scale | Testing of materials, methods, or chemical processes on a small scale. |
Beneficiation | Any process that improves (benefits) the economic value of the ore by removing the gangue minerals, which results in a higher grade product (concentrate) and a waste stream (tailings). |
Concentrate | Ore concentrate, dressed ore or simply concentrate is the product generally produced by metal ore mines. The raw ore is usually ground finely in various comminution operations (ie the reduction of solid materials from one average particle size to a smaller average particle size by crushing, grinding etc) and gangue (waste) is removed, thus concentrating the metal component. |
Flotation | Method used to separate and concentrate ores by altering their surfaces to a hydrophobic or hydrophilic condition - that is, the surfaces are either repelled or attracted by water. |
Gangue | The commercially worthless material that surrounds, or is closely mixed with, a wanted mineral in an ore deposit |
Hydrometallurgical refining | Extractive metallurgy is the practice of removing valuable metals from an ore and refining the extracted raw metals into a purer form. Hydrometallurgy uses aqueous solutions to extract metals from ores (leaching). |
Sighter test | Sighter testwork establishes if the desired metals can be extracted from the ore easily or not. |
Stereomicroscopy | The stereo, stereoscopic or dissecting microscope is an optical microscope variant designed for low magnification observation of a sample, typically using light reflected from the surface of an object rather than transmitted through it. |
Total Graphitic Carbon or TGC | Carbon in rocks may be reported as total carbon (organic carbon + carbon in carbonate minerals + carbon as graphite) or as total graphitic carbon (total carbon - (organic + carbonate carbon). Β Therefore, when total graphitic carbon (TGC) is to be reported, organic carbon and carbon in carbonate minerals such as calcite should be removed before analysing TGC. |
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For further information, please contact:
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Alba Mineral Resources plc George Frangeskides, Executive Chairman | +44 20 3907 4297 Β |
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Cairn Financial Advisers LLP (Nomad) James Caithie / Liam Murray | +44 20 7213 0880 Β |
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First Equity Limited (Broker) Jason Robertson | +44 20 7374 2212 Β |
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Yellow Jersey PR (Financial PR/ IR) Sarah Hollins/Harriet Jackson/Henry Wilkinson alba@yellowjerseypr.com | +44Β 20 3004 9512 Β Β |
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Alba's Project and Investment Portfolio
Project (commodity) | Location | Ownership |
Mining Projects | ||
Amitsoq (graphite) | Greenland | 90% |
Clogau (gold) | Wales | 90% |
Inglefield (copper, cobalt, gold) | Greenland | 100% |
Limerick (zinc-lead) | Ireland | 100% |
Melville Bay (iron ore) | Greenland | 51% |
TBS (ilmenite) | Greenland | 100% |
Oil & Gas Investments | ||
Brockham (oil) | England | 5% |
Horse Hill (oil) | England | 11.765% |
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