Chart 1
Figure 4
Tantalum Standards
NW pegmatite core
BRISBANE, Australia, July 31, 2023 (GLOBE NEWSWIRE) -- Allkem Limited (ASX: AKE, “Allkem” or the “Company”) provides an Ore Reserve update for its Mt Cattlin operation in Western Australia.
KEY POINTS
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Mineral Resource updated to reflect depletion due to mining since 31 Dec 2022 and modest increases due to adjustment to cut-off grade (0.3%) and new pit shell of USD 1,500.
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The Ore Reserve and planned mining schedule suggests a projected Life-of-Mine for the next 4-5 years (2027-2028) via open pit mining methods.
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The Ore Reserve has been updated to account for:
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Mining depletion since the previous Reserve dated 31 March 2023
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Adjustment to cut-off grade of 0.3% in the same pit shell design as modelled 31 March 2023
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A correction to the previously stated Ore Reserve released 16 June 2023 which contained a modelling error.
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The increasing waste/ore strip ratio at depth to access ore via open pit mining methods is being evaluated against an alternate underground mining option.
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An underground Feasibility Study is expected to be delivered in CY24. It will enable a variety of scenarios to be modelled and will ensure an optimised future mining method is selected.
ORE RESERVE ESTIMATE
The Mt Cattlin Ore Reserve estimate is based on an updated Mineral Resource Estimate released on 17 April 2023. The Mineral Resource was updated after the completion of a major infill drilling program which successfully upgraded Inferred Mineral Resources.
Allkem has reviewed and updated the Mt Cattlin Ore Reserve (Table 1 below), incorporating infill drilling results from the 2NW deposit, depleted mined material and site stockpiles at 30 June 2023 and material to be mined after this date are presented in accordance with JORC (2012) Ore Reserve Reporting.
Table 1: Mt Cattlin Ore Reserve Update as at 30 June 2023
Classification | Location | Ore Tonnes | Grade Li2O (%) | Grade Ta2O5 | Contained | Contained |
Proved | In-situ | 0.2 | 0.9 | 120 | 1 | 45 |
Probable | In-situ | 5.2 | 1.3 | 130 | 69 | 1,500 |
| Stockpiles | 1.8 | 0.8 | 95 | 13 | 396 |
Total Ore Reserve | 7.1 | 1.2 | 120 | 84 | 1,900 |
Notes: Ore Reserves mine designs were conducted on a 0.4% Li2O cut-ff grade and Ore Reserves are reported above a marginal cut-off grade of 0.3 % Li2O. Estimates have been rounded to a maximum of two significant figures, thus sum of columns may not equal.
A breakdown of the adjustments are shown in Table 2 and corresponding Chart 1 below.
Table 2: Changes (Mt) in Ore Reserve March 2023 to June 2023
Description | Balance | Grade Li2O (%) | Increase |
| Decrease |
Ore Reserve March 31st 2023 | 7.8 | 1.2 | - |
| - |
Depletion | -0.4 | 1.3 | - | - | 0.4 |
Changes to un-mined open pit surface topography/adjustment for in pit tailings | -0.4 | 1.2 | - | - | 0.4 |
Marginal COG from 0.4% to 0.3% | 0.1 | 0.4 | 0.1 |
| - |
Ore Reserve 30 June 2023 | 7.1 | 1.2 | 0.1 | - | 0.8 |
Chart 1: Changes (Mt) in Ore Reserve reported March 2023 to June 2023
Reserve Methodology
Pit optimisations have been carried out using a fixed spodumene concentrate sale price of US$1,500/t and an exchange rate of 0.7 USD:AUD. Whittle pit optimisation software has been used to identify the preferred pit shell on which the pit design was based.
The target design shells were selected to provide a logically phased mine life that maintains future optionality to further evaluate the trade-off between the larger second phase cutback compared to, or in conjunction with, underground mining.
The current mine sequence is based on:
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Continued mining of the current stage (Stage 3) of the 2NW pit to completion,
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Phasing of the next stage (Stage 4) into two separate cutbacks to manage the strip ratio and provide smoother ore supply to the processing plant; and
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The timing of a Mining Proposal that has been lodged with WA regulators to extend the current pit and allow for both cutbacks. This is expected to take place by end of CY23.
The mine plan is shown to be technically and financially feasible with an overall life of mine (LOM) ore: waste strip ratio of 21.5:1. A suitable cashflow positive buffer exists below the assumed product prices to provide confidence that the Ore Reserve estimate will be financially viable within a reasonably expected range of possible product prices.
MINERAL RESOURCES & MINERAL RESOURCES EXCLUSIVE OF ORE RESERVES
Mt Cattlin is an active mine and the new NW pit is the 5th sequential open pit in development and production. The Mineral Resource had been tested against an RPEEE open pit design with a USD 1,500 revenue factor, and reported, (Table 3) depleted of mining, at a cut-off grade of 0.3% lithia. Pegmatite mineralisation is wireframed and modelled at COG > 0.3% lithia. Tonnages and grades reported are depleted for mining completed to 30 June, 2023. In addition, separate Mineral Resource tonnages and grades are reported, exclusive of Ore Reserves, on the same basis (Table 4), below or outside the current pit design.
Table 3: Mt Cattlin Mineral Resource Update as at 30 June 2023, depleted for mining, within a RPEEE shell USD 1,500
Classification | Location | Ore Tonnes | Grade Li2O (%) | Grade Ta2O5 | Contained | Contained |
Measured | In-situ | 0.2 | 1.0 | 171 | 2 | 44 |
Indicated | In-situ | 7.2 | 1.4 | 147 | 98 | 2,221 |
Inferred | In-situ | 0.2 | 1.1 | 133 | 2 | 48 |
Indicated | Stockpiles | 1.8 | 0.8 | 95 | 13 | 396 |
Total Mineral Resource | 9.4 | 1.2 | 137 | 115 | 2,700 |
Notes: RPEEE optimisations were conducted on a 0.4% Li2O cut-ff grade and are reported above a marginal cut-off grade of 0.3 % Li2O. Estimates have been rounded to a maximum of two significant figures, thus sum of columns may not equal
Table 4: Mt Cattlin Mineral Resources Update as at 30 June 2023, depleted for mining, exclusive of Ore Reserves
Classification | Location | Ore Tonnes | Grade Li2O (%) | Grade Ta2O5 | Contained | Contained |
Measured | In-situ | 0.1 | 1.0 | 179 | 1.0 | 39 |
Indicated | In-situ | 3.2 | 1.4 | 201 | 44.8 | 1417 |
Inferred | In-situ | 0.6 | 1.1 | 207 | 6.6 | 273 |
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Total Mineral Resource | 3.9 | 1.3 | 201 | 52.4 | 1,700 |
Notes: Mineral Resources, exclusive of Ore Reserves are reported above a marginal cut-off grade of 0.3 % Li2O. Estimates have been rounded to a maximum of two significant figures, thus sum of columns may not equal.
UNDERGROUND FEASIBILITY STUDY
The Underground Feasibility Study is underway and will trade off optimised mining methodologies to improve the most beneficial/more economic outcomes. It is expected to be delivered in CY24.
Step out drilling
It was observed that both the USD 1,100 and 1,500 RPEEE Mineral Resource iterations remain limited by a lack of drilling data which will be resolved by further step out drilling planned for later in CY23.
RESOURCE AND RESERVE CONTROLS & GOVERNANCE
Allkem continues to evolve processes to ensure that quoted Mineral Resource and Ore Reserve estimates are subject to internal controls and external review. Mineral Resource and Ore Reserves are estimated and reported in accordance with the 2012 edition of the JORC Code. Further information is available in the Appendices and JORC Table 1.
Allkem stores and collects exploration data using industry standard software that contains internal validation checks. Exploration samples from drilling have certified reference material standards introduced to the sample stream at set ratios, typically 1 per 25 samples. These are reported as necessary to the relevant Competent Persons to assess both accuracy and precision of the assay data applied to resource estimates. In resource modelling, block models are validated by checking the input drill hole composites against the block model grades by domain.
Allkem engages independent, qualified experts on a commercial fee for service basis, to undertake Mineral Resource and Ore Reserve audits. Allkem internally reconciles the resource outcomes to validate both the process and the outcome.
The Company has developed its internal systems and controls to maintain JORC compliance in all external reporting, including the preparation of all reported data by Competent Persons who are members of the Australasian Institute of Mining and Metallurgy or a ‘Recognised Professional Organisation’. As set out above, the Mineral Resource and Ore Reserve statements included in this announcement were reviewed by suitably qualified Competent Persons (below) prior to their inclusion, in the form and context announced.
PROJECT ECONOMICS
Operating costs
Operating cash costs for the LOM are estimated at US$969/dmt produced. It incorporates the remainder of the current Stage 3 open pit, Stage 4 open pits, and processing of end-of-life stockpiles from 1 July 2023 to end of mine life.
The table below proves a summary of the estimated LOM annual unitary cost by category.
Table 3: Estimated LOM operating cost by category
LOM Operating Cash Cost | US$/dmt produced |
Costs |
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Mining | 471 |
Processing | 278 |
General & Administration | 71 |
Site Operating Costs | 820 |
Transport & Logistics | 40 |
Cash & Operating Costs | 860 |
Royalties | 121 |
By-Product credits | -12 |
FOB Cash Cost | 969 |
Commodity prices
Forecast pricing for benchmark 6.0% Li2O spodumene concentrate has been sourced from independent market analyst group Wood Mackenzie1 and discounted for costs and penalties to give a Realised Price. The final pricing used is effectively net AUD$ FOB.
Tantalite (Ta2O5) concentrate is a by-product that contributes meaningful, but not material, revenue to the project. A flat sale price based on existing contracts has been applied to expected production.
A forward USD: AUD exchange rate forecast provided by Allkem has been used for this study, as shown in Table 4.
Table 4: Forward Estimates for Concentrate Price and Foreign Exchange
Period | Realised Li2O | Exchange rate | Realised Li2O | Realised Ta2O5 |
US$/dmt | AUD:USD | A$/dmt | A$/dry lb | |
H2 CY23 | 4,048 | 0.70 | 5,783 | 34.72 |
CY24 | 2,074 | 0.70 | 2,963 | 34.72 |
CY25 | 1,425 | 0.70 | 2,036 | 34.72 |
CY26 | 2,375 | 0.70 | 3,393 | 34.72 |
CY27 | 2,103 | 0.70 | 3,004 | 34.72 |
CY28 | 1,762 | 0.70 | 2,517 | 34.72 |
H1 CY29 | 1,486 | 0.70 | 2,123 | 34.72 |
The cashflow model was also tested at a conservative realised price of US$1,500/dmt Li2O in the optimisation, and cashflows remained positive for the overall Ore Reserve, and on each stage.
Economic evaluation
An economic evaluation was conducted by consultants Entech Pty Ltd using financial data sourced from Allkem, independent market analysis, and competitive tender.
The 2023 Ore Reserve Statement is forecast to generate a NPV of A$1.4B (US$0.9B) when evaluated with the prices in Table 4. As an existing operation, Mt Cattlin requires only minor initial capital expenditure to support the Stage 4 expansion, and low total project capital requirements of approximately A$115m (US$80m).
The economic model calculates Net Present Value (NPV) at a discount rate of 10% over the LOM from 30 June 2023. The NPV is based on financial model period cashflows, without allowance for taxation, depreciation, or financing provisions. The summary of this is shown in Table 5.
Table 5: Summary of Mt Cattlin Project Economics
Parameter | Unit | Stage 3 | Stage 4-1 | Stage 4-2 | Closure Stockpiles | Total |
Product Produced | Mt | 0.3 | 0.2 | 0.3 | 0.1 | 0.9 |
Life-Of-Mine Revenue | A$B | 1.4 | 0.5 | 0.8 | 0.3 | 3.0 |
Life-Of-Mine Total Expenditure | A$B | 0.3 | 0.3 | 0.6 | 0.2 | 1.4 |
Life-Of-Mine Free Cashflow | A$B | 1.1 | 0.1 | 0.3 | 0.1 | 1.6 |
Free Cashflow Margin | % | 79% | 25% | 30% | 35% | 53% |
Life-Of-Mine NPV | A$B | 1.0 | 0.1 | 0.2 | 0.1 | 1.4 |
Sensitivity analysis
Sensitivity analysis was conducted on the following variables (+/-20%) and quantified with the NPV outputs:
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Revenue factors: spodumene concentrate price, currency exchange rate and plant recovery.
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Cost factors: mining operating costs and processing operating costs
The results are graphically summarised in Figure 4. The outputs show the expected heightened sensitivity from revenue factors compared to cost factors. The plant recovery and revenue trends mimic each other, and currency exchange rate (FX) is the inverse. The cost sensitivity trends of the mining and processing operating costs mimic each other with mining being somewhat influential on cashflow and NPV due to being a larger overall cost.
Figure 4: NPV Sensitivity to Key Revenue and Cost Factor Variables
This release was authorised by Mr Martin Perez de Solay, CEO and Managing Director of Allkem Limited.
Allkem Limited | Investor Relations & Media Enquiries | Connect |
IMPORTANT NOTICES
This investor ASX/TSX release (Release) has been prepared by Allkem Limited (ACN 112 589 910) (the Company or Allkem). It contains general information about the Company as at the date of this Release. The information in this Release should not be considered to be comprehensive or to comprise all of the material which a shareholder or potential investor in the Company may require in order to determine whether to deal in Shares of Allkem. The information in this Release is of a general nature only and does not purport to be complete. It should be read in conjunction with the Company’s periodic and continuous disclosure announcements which are available at allkem.co and with the Australian Securities Exchange (ASX) announcements, which are available at www.asx.com.au.
This Release does not take into account the financial situation, investment objectives, tax situation or particular needs of any person and nothing contained in this Release constitutes investment, legal, tax, accounting or other advice, nor does it contain all the information which would be required in a disclosure document or prospectus prepared in accordance with the requirements of the Corporations Act 2001 (Cth) (Corporations Act). Readers or recipients of this Release should, before making any decisions in relation to their investment or potential investment in the Company, consider the appropriateness of the information having regard to their own individual investment objectives and financial situation and seek their own professional investment, legal, taxation and accounting advice appropriate to their particular circumstances.
This Release does not constitute or form part of any offer, invitation, solicitation or recommendation to acquire, purchase, subscribe for, sell or otherwise dispose of, or issue, any Shares or any other financial product. Further, this Release does not constitute financial product, investment advice (nor tax, accounting or legal advice) or recommendation, nor shall it or any part of it or the fact of its distribution form the basis of, or be relied on in connection with, any contract or investment decision.
The distribution of this Release in other jurisdictions outside Australia may also be restricted by law and any restrictions should be observed. Any failure to comply with such restrictions may constitute a violation of applicable securities laws.
Past performance information given in this Release is given for illustrative purposes only and should not be relied upon as (and is not) an indication of future performance.
Forward Looking Statements
Forward-looking statements are based on current expectations and beliefs and, by their nature, are subject to a number of known and unknown risks and uncertainties that could cause the actual results, performances and achievements to differ materially from any expected future results, performances or achievements expressed or implied by such forward-looking statements, including but not limited to, the risk of further changes in government regulations, policies or legislation; the risks associated with the continued implementation of the merger between the Company and Galaxy Resources Ltd, risks that further funding may be required, but unavailable, for the ongoing development of the Company’s projects; fluctuations or decreases in commodity prices; uncertainty in the estimation, economic viability, recoverability and processing of mineral resources; risks associated with development of the Company Projects; unexpected capital or operating cost increases; uncertainty of meeting anticipated program milestones at the Company’s Projects; risks associated with investment in publicly listed companies, such as the Company; and risks associated with general economic conditions.
Subject to any continuing obligation under applicable law or relevant listing rules of the ASX, the Company disclaims any obligation or undertaking to disseminate any updates or revisions to any forward-looking statements in this Release to reflect any change in expectations in relation to any forward-looking statements or any change in events, conditions or circumstances on which any such statements are based. Nothing in this Release shall under any circumstances (including by reason of this Release remaining available and not being superseded or replaced by any other Release or publication with respect to the subject matter of this Release), create an implication that there has been no change in the affairs of the Company since the date of this Release.
Competent Person Statement
The information in this announcement that relates to Exploration Results and Mineral Resources is based on information compiled by Albert Thamm, B.Sc. (Hons)., M.Sc. F.Aus.IMM (203217), a Competent Person who is a Fellow of The Australasian Institute of Mining and Metallurgy. Albert Thamm is a full-time employee of Galaxy Resources Pty. Limited. Albert Thamm has sufficient experience that is relevant to the style of mineralization and type of deposit under consideration and to the activity being undertaken to qualify as a Competent Person as defined in the 2012 Edition of the ‘Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves’. Albert Thamm consents to the inclusion in this announcement of the matters based on his information in the form and context in which it appears.
The information in this announcement that relates to the 31 March 2023 Mt Cattlin Ore Reserve is based on information compiled by Daniel Donald, B. Eng. (Mining), F.Aus.IMM (210032), a Competent Person who is a Member of the Australasian Institute of Mining and Metallurgy. Daniel Donald is an employee working for Entech Mining Pty Ltd and has been engaged by Allkem Limited to prepare the documentation for the Mt Cattlin operation on which the Ore Reserve Report is based, for the period ended 31 March 2023, and has sufficient experience that is relevant to the style of mineralization and type of deposit under consideration and to the activity being undertaken to qualify as a Competent Person as defined in the 2012 Edition of the ‘Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves’. Daniel Donald consents to the inclusion in this announcement of the matters based on his information in the form and context in which it appears.
Technical information relating to the Company’s Mt Cattlin project contained in this release is derived from, and in some instances is an extract from, the technical report entitled “Mt Cattlin Stage 4 Expansion Project” (Technical Report) which has been reviewed and approved by Albert Thamm, F.Aus.IMM (who is an employee of Galaxy Resources Pty. Ltd) as it relates to geology, drilling, sampling, exploration, QA/QC and mineral resources and Daniel Donald F.Aus.IMM (an employee of Entech Pty Ltd) as it relates to mining methods, Ore Reserves, site infrastructure, capital cost, operating cost estimates, mining cost, financial modelling and economic analysis in accordance with National Instrument 43-101 – Standards for Disclosure for Mineral Projects. The Technical Report will be available for review under the Company’s profile on SEDAR at www.sedar.com.
Not for release or distribution in the United States
This announcement has been prepared for publication in Australia and may not be released to U.S. wire services or distributed in the United States. This announcement does not constitute an offer to sell, or a solicitation of an offer to buy, securities in the United States or any other jurisdiction, and neither this announcement or anything attached to this announcement shall form the basis of any contract or commitment. Any securities described in this announcement have not been, and will not be, registered under the U.S. Securities Act of 1933 and may not be offered or sold in the United States except in transactions registered under the U.S. Securities Act of 1933 or exempt from, or not subject to, the registration of the U.S. Securities Act of 1933 and applicable U.S. state securities laws.
APPENDIX 1 – JORC 2012 TABLE 1 DISCLOSURE
Section 1: Sampling Techniques and Data
MT CATTLIN LITHIUM PROJECT SAMPLING AND DATA | |||||||||
Sampling techniques | Nature and quality of sampling (e.g. cut channels, random chips, or specific specialized industry standard measurement tools appropriate to the minerals under investigation, such as down hole gamma sondes, or handheld XRF instruments, etc.). These examples should not be taken as limiting the broad meaning of sampling. | Pre-2017 | |||||||
Hole_Type | Count | Metres | % Drillholes | % Metres | |||||
DDH | 45 | 5,437.8 | 1.4 | % | 3.1 | % | |||
RC | 3,173 | 169,037.8 | 98.2 | % | 96.1 | % | |||
RC_DDT | 14 | 1,474.4 | 0.4 | % | 0.8 | % | |||
TOTAL | 3,232 | 175,950 | 100 | % | 100 | % | |||
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Drilling techniques | Drill type (e.g. core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc.) and details (e.g. core diameter, triple or standard tube, depth of diamond tails, face-sampling bit or other type, whether core is oriented and if so, by what method, etc.). | RC drilling hammer diameter was generally 4 & 5/8 inches in early exploration, from 2009 and 2010 the bit diameter was 5 ¼ inches. | |||||||
Logging | Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation, mining studies and metallurgical studies. | All DD, RC and OH (PC) and RAB intervals were geologically logged (where applicable); RQD (DD only), interval weights, recovery, lithology, mineralogy and weathering were recorded in the database. | |||||||
Sub- sampling techniques and sample preparation | If core, whether cut or sawn and whether quarter, half or all core taken. | Pre-2016 sampling | |||||||
Quality of assay data and laboratory tests | The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total. | Pre-2016 QAQC
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Verification of sampling and assaying | The verification of significant intersections by either independent or alternative company personnel. | Pre-2018 Verification |
Section 2: Reporting of Exploration Results
Criteria | JORC Code explanation | Commentary |
Mineral tenement and land tenure status |
| Mining Lease M74/244 was amalgamated and awarded on 04/08/2009 and is valid until 23/12/2030 and covers 1830 Ha. |
Exploration done by other parties |
| During the 1960’s WMC carried out an extensive drilling program to define the extent of local spodumene bearing pegmatite. The WMC work led onto a further investigation into project feasibility. |
Geology |
| The Mount Catlin Project lies within the Ravensthorpe Suite, with host rocks comprising both the Annabelle Volcanics to the west, and the Manyutup Tonalite to the east. The contact between these rock types extends through the Project area. |
Drill hole Information |
| Pre-2017 drilling reported 4 August 2015 by subsidiary GMM (ASX:GMM). Last prior resource and update was 28 November 2018 |
Data aggregation methods |
| Pre-2017 Data |
Relationship between mineralization widths and intercept lengths |
| All intersection grades have been reported previously as length weighted average grades using a 0.3% Li2O lower grade cut-off except where stated. |
Diagrams |
| Diagrams are included in the text above. |
Balanced reporting |
| All significant intersections above 0.3% Li2O have been fully reported in previous releases. |
Other substantive exploration data |
| Fe2O3 is modelled with Li and Ta to determine the effect of deleterious chemistry and mineralogy at or near pegmatite contacts and rafts of surrounding country rock with pegmatite. |
Further work |
| Development and extraction of the NW Pit Mineral Resource and Reserve. |
Section 3: Estimation and Reporting of Mineral Resources – Mt Cattlin
Criteria | JORC Code explanation | Commentary | ||
Database integrity |
| Pre-2017 | ||
Site visits |
| The reporting CP has completed several site visits since 2016. | ||
Geological interpretation |
| The geological interpretation is considered robust due to the nature of the geology and mineralisation. | ||
Dimensions | ·The extent and variability of the Mineral Resource expressed as length (along strike or otherwise), plan width, and depth below surface to the upper and lower limits of the Mineral Resource | The Mt Cattlin pegmatites strike north-south and are typically between 10 m and 30 m wide and are typically flat-lying or with a subtle dip east of around 5 to 10 degrees. Several different pegmatites have been identified, either as separate intrusions or due to fault offsets, over a strike length of 1,300 m, an across strike extent of 1,700 m and down to a depth of greater than 300 m below surface. | ||
Estimation and modelling techniques |
| Grade estimation for Li2O%, Fe2O3% and Ta2O5 ppm has been completed using Ordinary Kriging (OK) into pegmatite domains using Datamine, Studio RM software. Grade estimation of Fe2O3% has been completed using OK into the encapsulating mafic waste and late-stage mafic dyke, which intersects the pegmatites.
The Mineral Resource estimate has been validated using visual validation tools combined with volume comparisons with the input wireframes, mean grade comparisons between the block model and composite grade means and swath plots comparing the composite grades and block model grades by Northing, Easting and RL. | ||
Moisture | ·Whether the tonnages are estimated on a dry basis or with natural moisture, and the method of determination of the moisture content. | Tonnes have been estimated on a dry basis. | ||
Cut-off parameters | ·The basis of the adopted cut-off grade(s) or quality parameters applied | For the depleted reporting of the Mineral Resource Estimate, a 0.3 Li2O% cut-off within a USD 1,500 Whittle pit shell has been used. | ||
Mining factors or assumptions | ·Assumptions made regarding possible mining methods, minimum mining dimensions and internal (or, if applicable, external) mining dilution. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential mining methods, but the assumptions made regarding mining methods and parameters when estimating Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the mining assumptions made. | A Whittle pit optimisation has been run at 1,500 USD in order to generate a pit shell wireframe for Mineral Resource reporting purposes and to meet the RPEEE reporting requirement. | ||
Metallurgical factors or assumptions | ·The basis for assumptions or predictions regarding metallurgical amenability. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential metallurgical methods, but the assumptions regarding metallurgical treatment processes and parameters made when reporting Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the metallurgical assumptions made. | A Li2O% metallurgical recovery of 75% and Ta2O5 ppm recovery of 25% has been applied during the pit optimisation and generation of the RPEEE pit shell. | ||
Environmental factors or assumptions | ·Assumptions made regarding possible waste and process residue disposal options. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider the potential environmental impacts of the mining and processing operation. While at this stage the determination of potential environmental impacts, particularly for a greenfields project, may not always be well advanced, the status of early consideration of these potential environmental impacts should be reported. Where these aspects have not been considered this should be reported with an explanation of the environmental assumptions made | No environmental factors or assumptions have been incorporated into this Mineral Resource Estimate since Mt Cattlin is a producing operation with Environmental approvals and an Environmental Management Plan in place. | ||
Bulk density |
| No additional bulk density data has been collected in the NW Area. As a consequence, the bulk density values determined in the previous MRE (Nov 2018) have been assigned to the block model. | ||
Waste Lithologies | Oxide | 2.50 | ||
Transitional | 2.70 | |||
Fresh | 2.86 | |||
Unmineralized Pegmatite | Oxide | 2.42 | ||
Transitional | 2.62 | |||
Fresh | 2.78 | |||
Mineralised Pegmatite | Oxide | 2.47 | ||
Transitional | 2.71 | |||
Fresh | 2.72 | |||
Classification |
| The resource classification has been applied to the MRE based on the drilling data spacing, grade and geological continuity, quality of the estimation and data integrity. | ||
Audits or reviews | ·The results of any audits or reviews of Mineral Resource estimates. | This 2023 Mineral Resource estimate for Mt Cattlin has been peer reviewed and validated. Original outputs in Datamine/Studio have been translated into Dassault/Surpac for further development into regularised models for the development of diluted models. | ||
Discussion of relative accuracy/ |
| The relative accuracy of the Mineral Resource estimate is reflected in the reporting of the Mineral Resource as per the guidelines of the 2012 JORC Code. |
Section 4: Ore Reserves
Criteria | JORC Code explanation | Commentary |
Mineral Resource estimate for conversion to Ore Reserves | Description of the Mineral Resource estimate used as a basis for the conversion to an Ore Reserve. | The Mineral Resource estimate (MRE) used was prepared by Mining Plus Pty Ltd under the direction of Allkem and classified in accordance with the JORC 2012 guidelines. The MRE was natively prepared in Datamine software with a record date of 31 December 2022, and a summary was released to the ASX on 17 April 2023. |
Clear statement as to whether the Mineral Resources are reported additional to, or inclusive of, the Ore Reserves. | The Mineral Resources are reported inclusive of the Ore Reserves. | |
Site visits | Comment on any site visits undertaken by the Competent Person and the outcome of those visits. | The Competent Person has undertaken a site visit within the current reporting period. |
Study status | The type and level of study undertaken to enable Mineral Resources to be converted to Ore Reserves. | Mt Cattlin is a mature operating mine and a Feasibility Study (FS) investigating the continuation of current operations is the basis of the conversion of the MRE to an ORE. |
Cut-off parameters | The basis of the cut-off grade(s) or quality parameters applied. | A marginal cut-off grade of 0.3% Li2O has been used for reporting the ORE. |
Mining factors or assumptions | The method and assumptions used as reported in the Pre-Feasibility or Feasibility Study to convert the Mineral Resource to an Ore Reserve (i.e., either by application of appropriate factors by optimisation or by preliminary or detailed design). | An optimisation of the MRE was undertaken with General Mine Planning (GMP) software, both Geovia and Datamine products. Comparisons between the outputs showed them to be materially equivalent.
Where supplied by Allkem, these input parameters were reviewed by Entech and considered appropriate for the current spodumene concentrate market. |
The choice, nature and appropriateness of the selected mining method(s) and other mining parameters including associated design issues such as pre-strip, access, etc. | The ORE includes the Stage 4 North-West (NW) pit which is a down dip extension of the current Stage 3 NW pit i.e., deepening of current floor, and cutting back of the current pit rim. | |
The assumptions made regarding geotechnical parameters (e.g., pit slopes, stope sizes, etc), grade control and pre-production drilling. | A comprehensive geotechnical study appropriate for an FS level was undertaken by Entech to determine the pit design parameters used in the ORE. Three dedicated geotechnical diamond drill holes, totalling 651 m, located in the vicinity of the final pit walls were drilled, logged, sampled and laboratory tested to collect detailed geotechnical data. In addition, photogrammetric modelling of the current pit walls, structure digitisation, in-pit mapping and data from previous studies was utilised to characterise the rock mass and provide input data for stability analysis that were used to derive the recommended design parameters.
Pit designs were reviewed by Entech’s Principal Geotechnical Engineer to ensure compliance with geotechnical intent. | |
The major assumptions made, and Mineral Resource model used for pit and stope optimisation (if appropriate). | The underlying Mineral Resource model was jointly developed by independent consultant Mining Plus Pty Ltd and Allkem Ltd (see ASX release 17 April 2023). A dilution study was then carried out by consultant Orelogy Mine Consulting (Orelogy) to determine the appropriate methodology to create a diluted, regularised Mining Model that could be readily used in GMP software. The key steps and outcomes from the dilution study and modifications to create the Mining Model were:
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The mining dilution factors used. | No external dilution factors have been applied. The Mining Model described above compared to the source undiluted model has a back-calculated dilution of 16%. | |
The mining recovery factors used. | No external mining recovery factors have been applied. The Mining Model described above compared to the source undiluted model has a back-calculated ore loss of 5.7%. | |
Any minimum mining widths used. | A minimum mining width of 40 m has been applied in the pit designs. | |
The manner in which Inferred Mineral Resources are utilised in mining studies and the sensitivity of the outcome to their inclusion. | Inferred Mineral Resources comprise 12% of the MRE and were used to inform the optimisation. | |
The infrastructure requirements of the selected mining methods. | The ORE as an extension of current operations, and the current site infrastructure is suitable for proposed mining methods. | |
Metallurgical factors or assumptions | The metallurgical process proposed and the appropriateness of that process to the style of mineralisation. | Ore is processed through the existing crushing, screening, ore sorting, and heavy media separation (HMS) plant with a nominal and permitted capacity of 1.8 million tonnes (Mt) per annum. The Mt Cattlin plant has been in operation for over a decade and is suitable for this style of mineralisation. |
Whether the metallurgical process is well-tested technology or novel in nature. | The Mt Cattlin plant is comprised of well tested technology and suited to the production of saleable spodumene concentrate. | |
The nature, amount and representativeness of metallurgical test work undertaken, the nature of the metallurgical domaining applied and the corresponding metallurgical recovery factors applied. | As an operating processing facility, the Mt Cattlin plant has amassed significant knowledge and expertise in the treatment of the Mt Cattlin ores. | |
Any assumptions or allowances made for deleterious elements. | Allowances have been made for iron oxide (Fe2O) content of the spodumene concentrate. The (potential) penalty element is estimated in the MRE, reported in the ORE, monitored during processing, and quantified in the final spodumene concentrate product. Revenue pricing used in the cashflow model incorporates likely penalty charges. | |
The existence of any bulk sample or pilot scale test work and the degree to which such samples are considered representative of the orebody as a whole. | The ORE is a continuation of the ore zones that have been successfully mined and processed at Mt Cattlin. Bulk samples and/or pilot scale testing is not required due to the demonstrated process flowsheet performance. | |
For minerals that are defined by a specification, has the ore reserve estimation been based on the appropriate mineralogy to meet the specifications? | The Ore Reserves have been based on lithia (Li2O), Tantalite (Ta2O5), and iron oxide (Fe2O) grade ranges that are acceptable to existing sales contracts and readily saleable into the international market. | |
Environmental | The status of studies of potential environmental impacts of the mining and processing operation. Details of waste rock characterisation and the consideration of potential sites, status of design options considered and, where applicable, the status of approvals for process residue storage and waste dumps should be reported. | The Mt Cattlin mine site is an operating and mature operation with well-understood impacts and established environmental management systems and capability. The site operating procedures are consistent with the principles of ISO 14001:2015 Environmental Management Systems. |
Infrastructure | The existence of appropriate infrastructure: availability of land for plant development, power, water, transportation (particularly for bulk commodities), labour, accommodation; or the ease with which the infrastructure can be provided, or accessed. | The Mt Cattlin mine site is a mature operating mine. All mining, processing, power and water supplies, road and port infrastructure are in place and operational. |
Costs | The derivation of, or assumptions made, regarding projected capital costs in the study. | The FS has assessed and included appropriate capital costs. As an existing operation the capital required for the operating life of the ORE is not significant. |
The methodology used to estimate operating costs. | The operating costs have been derived two sources:
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Allowances made for the content of deleterious elements. | The revenue prices used in the economic analysis have incorporated all applicable penalty charges as modelled, including deductions for product grade less than the benchmark 6.0% spodumene grade (SC6), and for any iron oxide content above limits. | |
The source of exchange rates used in the study. | The exchange rate of consequence is Australian to United States of America (USD:AUD) currency exchange rate as spodumene product is sold in US dollars (USD). As an existing Western Australian based operation, most costs are in denominated in AUD. | |
Derivation of transportation charges. | Product transportation and handling charges (road haulage from Mt Cattlin to Esperance port, and Esperance port costs) were provided by Allkem and were derived from existing contracts. | |
The basis for forecasting or source of treatment and refining charges, penalties for failure to meet specification, etc. | The headline external pricing forecasts for spodumene concentrate grading 6.0 % Li2O were discounted for expected product grades of between 5.2% Li2O and 5.5% Li2O. The discounts were derived from existing contract penalty charges. Penalties were also applied to Fe2O3 exceedances if they occurred. | |
The allowances made for royalties payable, both Government and private. | Selling costs have allowed for a 5.0% ad-valorum Western Australian state royalty and $1.50/t of ore processed third party royalty. | |
Revenue factors | The derivation of, or assumptions made regarding revenue factors including head grade, metal or commodity price(s) exchange rates, transportation and treatment charges, penalties, net smelter returns, etc. | The ORE head grade is reported by the GMP software interrogating the diluted mining model within the designed pit. Normal good practice checks have been made in this process, as well as reporting through alternative GMP software, and comparing to similar internal work by Allkem. |
The derivation of assumptions made of metal or commodity price(s), for the principal metals, minerals and co-products. | As described above, the commodity price assumptions have been taken from independent market analysts and existing contracts and are deemed appropriate. | |
Market assessment | The demand, supply and stock situation for the particular commodity, consumption trends and factors likely to affect supply and demand into the future. | An Independent market researcher (commercial in confidence) forecasts for demand, supply, and stock levels during the likely market window of the product of this ORE have been used to characterise the international market for spodumene concentrate. |
A customer and competitor analysis along with the identification of likely market windows for the product. | The Mt Cattlin spodumene concentrate is currently sold through offtake agreements mainly to mainland Chinese convertors. Offtake agreements have pricing conditions reflecting spodumene market prices. | |
Price and volume forecasts and the basis for these forecasts. | Overall market supply and demand, along with customer and competitor factors have been considered in the compiling of the pricing forecast applicable to this ORE. | |
For industrial minerals the customer specification, testing and acceptance requirements prior to a supply contract. | Mt Cattlin concentrates are sold into typical international specifications, the more relevant specifications being Li2O grade, Ta2O5 grade (both revenue factors), and Fe2O3 grade (a potential penalty factor). Mt Cattlin product does not typically attract Fe penalties, and the lithia grade is forecast to range between 5.5% Li2O and 5.2% Li2O depending on market assessment. | |
Economic | The inputs to the economic analysis to produce the net present value (NPV) in the study, the source and confidence of these economic inputs including estimated inflation, discount rate, etc. | The cashflow model is uninflated and applies a 10% discount rate to calculate the project NPV, which was robustly positive. |
NPV ranges and sensitivity to variations in the significant assumptions and inputs. | The cashflow model has been tested for sensitivity to key economic assumptions. As is typically found, the revenue assumptions (e.g., sale price, USD:AUD exchange rate, head grade, plant recovery) have a much greater influence than cost assumptions (e.g., operating costs, capital costs). At 20% individual variances to any of these variables the project remains robustly economic over life of mine and generates positive cashflows. | |
Social | The status of agreements with key stakeholders and matters leading to social licence to operate. | As an operating site Mt Cattlin has a well-established and implemented Environmental Management Plan and suite of operating procedures consistent with the principles of ISO 14001:2015 Environmental Management Systems and includes, but is not limited to:
Allkem have advised the Competent Person that there are no current issues that would be expected to endanger the ‘social licence to operate’. |
Other | To the extent relevant, the impact of the following on the project and/or on the estimation and classification of the Ore Reserves: | Commentary below. |
Any identified material naturally occurring risks. | The FS has investigated the potential for flooding via a hydrology study which informed the design of the abandonment bund and the Cattlin Creek diversion channel and associated bunding. No residual issues were apparent. | |
The status of material legal agreements and marketing arrangements. | All material legal and marketing agreements are in place and accounted for. | |
The status of governmental agreements and approvals critical to the viability of the project, such as mineral tenement status, and government and statutory approvals. There must be reasonable grounds to expect that all necessary Government approvals will be received within the timeframes anticipated in the Pre-Feasibility or Feasibility study. Highlight and discuss the materiality of any unresolved matter that is dependent on a third party on which extraction of the reserve is contingent. | The ORE stated are located on active mining leases, in good standing. | |
Classification | The basis for the classification of the Ore Reserves into varying confidence categories. | The Mineral Resources above an in-situ economic cut-off grade within the designed open pit and below the surveyed topography surfaces (as of 31 March 2023) have been modified by the application of suitable modifying factors and has been classified Probable, based on the Measured or Indicated classification of the Mineral Resource estimate. |
Whether the result appropriately reflects the Competent Person’s view of the deposit. | Mr. Daniel Donald, the Competent Person for this Ore Reserve estimation, has reviewed the work undertaken to date and considers that it is sufficiently detailed and relevant to allow declaration of these Ore Reserves. | |
The proportion of Probable Ore Reserves that have been derived from Measured Mineral Resources (if any). | As described above, all surface stocks have been classified as Probable when it may have been possible to classify some as Proved. Any potential upgrading would have no material effect on the ORE. | |
Audits or reviews | The results of any audits or reviews of Ore Reserve estimates. | The Ore Reserve has been estimated by independent consultants Entech Pty Ltd with assistance from Allkem and Strategic Metallurgy with the MRE, mining model, and processing areas respectively. |
Discussion of relative accuracy/ confidence | Where appropriate a statement of the relative accuracy and confidence level in the Ore Reserve estimate using an approach or procedure deemed appropriate by the Competent Person. For example, the application of statistical or geostatistical procedures to quantify the relative accuracy of the reserve within stated confidence limits, or, if such an approach is not deemed appropriate, a qualitative discussion of the factors which could affect the relative accuracy and confidence of the estimate. | The Competent Person deems that the methodology applied to arrive at the Ore Reserve estimate for Mt Cattlin is appropriate and defendable. |
The statement should specify whether it relates to global or local estimates, and, if local, state the relevant tonnages, which should be relevant to technical and economic evaluation. Documentation should include assumptions made and the procedures used. | The statement relates to global estimates of a mine scale. | |
Accuracy and confidence discussions should extend to specific discussions of any applied Modifying Factors that may have a material impact on Ore Reserve viability, or for which there are remaining areas of uncertainty at the current study stage. | Confidence in the application of the modifying factors is appropriate for the estimate. | |
It is recognised that this may not be possible or appropriate in all circumstances. These statements of relative accuracy and confidence of the estimate should be compared with production data, where available. | The contract mining cost data which was derived from competitive market tender has also been compared to actual site production data. All other operating cost data is directly derived from actual production data. In summary, the cost data used compares very well with production data and incorporates the inflationary/pandemic effects seen over the previous several years. |
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