Mt Cattlin Resource, Reserve and Operations Update

2022-08-24 20:31:05

BRISBANE, Australia, Aug. 24, 2022 (GLOBE NEWSWIRE) — Allkem Limited (ASX: AKE, “Allkem” or the “Company”) provides an update for its Mt Cattlin operation in Western Australia.

KEY POINTS

  • Mineral Resource tonnage increased 21% to 13.3Mt @ 1.2% Li2O and 131 ppm Ta2O5 at a cut-off grade of 0.4% Li2O, the increase principally reflecting the impact of using a US$1,100/t pit shell at 6% Li2O concentrate grade (c.f. US$900/t in 2021) and net of mining depletion
  • Ore Reserve tonnage decreased 28% to 5.8Mt @ 0.98% Li2O and 113 ppm Ta2O5 at cut-off grade of 0.4% Li2O reflecting depletion from mining activities within the current mine design between 31 March 2021 to 30 June 2022
  • A major 147 hole, 32,685m drill programme commenced in April with the objective of extending mine life through increasing resources and upgrading resource categories. Drilling results will inform mining studies and a revised Mineral Resource and Ore Reserve
  • Delays in planned pre-stripping activities have deferred exposure of main ore sources in the 2NW pit which will limit Q1 FY23 production and reduce FY23 guidance from 160-170kt to 140-150 kt of spodumene concentrate SC6. Production volumes are expected to increase each quarter throughout the year as pre-stripping is completed
  • This deferred production will be partially offset by the sale of 130ktpa of lower grade spodumene concentrate to existing customers in the first half of FY23

PRODUCTION GUIDANCE UPDATE

Recent results from Mt Cattlin mining operations, as well impacts from on-going labour shortages in Western Australia, have resulted in a review of production guidance for FY23.

Many Western Australian mining operations continue to suffer from a severe shortage and high turnover of staff which is exacerbated by COVID-19 related absences. At Mt Cattlin this has resulted in a further delay in pre-strip activities at the new 2NW pit.

Previous production guidance assumed that a small upper lens of mineralisation would provide ore for processing while the main ore zones are being exposed. Unfortunately, the mineralogy of this upper lens has not been amenable to processing through the plant as currently configured due to its fine-grained nature. This will lower production for the next 4-6 weeks while the main orebody is exposed by pre-stripping operations, at which time normal production levels will resume.

Consequently, Allkem currently anticipates that FY23 annual production at Mt Cattlin will be approximately 140-150kt compared to the previous guidance of 160-170kt. Production will be split approximately 15%, 20%, 30%, 35% across each respective quarter and with FY23 costs expected to be approximately US$900/t. As advised in the June Quarterly Report, ore grades will increase from 0.93-0.94% in the current year to 1.17% in FY24 which will have a beneficial impact on costs and production.

Mitigation actions at site are already well underway and include the mobilisation of an additional mining contractor, the replacement and upsizing of mining equipment with the existing mining contractor, the installation of magnetic ore sorters to allow the processing of low-grade stockpiles and advanced metallurgical test work on the fine-grained ore.

So far this quarter Allkem has sold two trial shipments for a total of 30,000 tonnes of low grade (~1.3%) spodumene concentrate at an average realised price of between US$500/t and US$600/t CIF. In order to offset the deferred delivery of SC6 spodumene volumes, Allkem is currently in advanced discussions with existing customers to substitute up to 100,000 tonnes of the lower grade material during the current half year.

RESOURCE EXTENSION DRILLING

Allkem commenced a three-phase resource extension program in mid-April that targets 147 holes for approximately 32,685 metres of reverse circulation (“RC”) drilling.

The first two phases will target the immediate extension to mine-life at depth. The first phase aims to convert ~3.2Mt of resource from the inferred to indicated category. The second phase will test two pegmatite lenses of approximately 4.2Mt of existing inferred resource along strike and at depth in conjunction with a study to evaluate either the opencut or underground development of potential resource extensions.

As of this date of this announcement, 60 holes and approximately 14,000m of drilling had been completed and an update on results will be provided later in September. The current drilling program is expected to be completed towards the end of CY22 and results have not been incorporated in the 2022 Mineral Resource estimate.

Figure 1

MINERAL RESOURCE

The Mineral Resource Estimate at 30 June 2022 is presented in Table 1 and represents the combination of the 2018 Mineral Resource with a stand-alone 2021 2NW pit estimate, depleted for mining activities from 31 March 2021 to 30 June 2022. As in previous years the cut-off grade used was 0.4% Li2O whilst the pit shell used within which to estimate the Mineral Resource was generated at US$1,100/t at 6% Li2O concentrate grade (c.f. US$900/t in 2021).

Table 1: Mt Cattlin Mineral Resource at 30 June 2022

Category   Tonnage Grade Grade Contained
Metal
Contained
metal
Nett Variance to
2021 Statement
    Mt % Li2O ppm Ta2O5 (‘000) t Li2O lbs Ta2O5 %
Measured In-situ -100%
Indicated In-situ 4.5 1.3 135 59 1,339,000 -6%
  Stockpiles   2.4 0.8 122 19 646,000 -20%
Inferred In-situ 6.4 1.3 131 83 1,850,000 121%
Total Resource at 30 June 2022   13.3 1.2 131 161 3,835,000 21%
Depletion             Notes
Measured   -0.3 1.6 236 -5 -156,000 2NE Pit
Indicated + Inferred   -0.8 1.6 330 -13 -582,000 2NE Pit
Stockpiles   -0.6 0.8 122 -5 -161,000 Surface
Addition             Notes  
Measured    – No GC drilling
Indicated   0.3 1.1 146 3 97,000 Change in RPEEE + 2SW deeps
Inferred   3.7 1.3 141 49 1,150,000 Change in RPEEE
Stockpiles (Indicated)    – Depleted as 2NW pre-strip developed
Total Resource at 31 March 2021   11.0 1.2 151.0 131.8 3,674,000

Notes: Reported at cut-off grade of 0.4% Li2O contained within a pit shell generated at a spodumene price of USD1,100 at 6% Li20. The preceding statements of Mineral Resources conforms to the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (JORC Code) 2012 edition. All tonnages reported are dry metric tonnes. Excludes mineralisation classified as oxide and transitional. Minor discrepancies may occur due to rounding to appropriate significant figures. RPEEE is defined as reasonable prospects for eventual economic evaluation.

The FY2022 Mineral Resource estimate takes into account both mining of resources from the current open pit mine and depletion of stockpiles, and includes results from the 2021 infill drilling results from the 2NW deposit. Remnant Mineral Resources under the backfilled 2SW pit has also been included as potential underground feed.

A description of the major factors that resulted in changes from the 2021 Mineral Resource to the 2022 Mineral Resource are as follows:

  • Resource model depletion of 1.4 Mt of material mined at a grade of 1.62% Li2O;
  • Stockpiles depleted by approximately 510Kt;
  • Decline in Measured and Indicated grade due to the mining of higher-grade material in H2 CY21 compared to the life of mine grade;
  • Reclassification of the RPEEE input revenue factor from USD 900 to 1,100 (at AUD/USD 0.70) for the generation of the pit shell within which the in-pit resource is estimated –this development envelope is currently subject to development drilling; and
  • An updated, depleted and integrated geological model in 2021.

The Mineral Resource estimate, mining depletion and reporting was completed by Allkem staff. Allkem has assumed responsibility for the logging, sampling, analytical and quality assurance/quality control protocols currently in place for estimates and depletions.

ORE RESERVE

Allkem has reviewed and updated the Mt Cattlin Ore Reserve, incorporating 2021 infill drilling results from the 2NW deposit, the depletion of the 2NE pit and evaluation of remnant deeper resource under the 2SW pit. Within this review, depleted mined material and site stockpiles at 30 June 2022 and material to be mined after this date are presented in accordance with JORC (2012) Ore Reserve Reporting.

Mt Cattlin’s Ore Reserve at 30 June 2022 is presented in Table 3 and is based on the remaining Ore Reserves with the current mine design utilising the model from the 2021 Mineral Resource estimate with the application of modifying factors.

Like the 2021 annual review, modifying factors and mining reconciliation were reviewed by the Competent Person and reflect Allkem’s continued strategy to utilise front-end optical sorters to upgrade and process low-grade stockpiled ore. A dilution factor of 17% applied to the Ore Reserve and a mining recovery of 93% of diluted material reflects the current practice of mining to horizontal flitches and benches.

At 30 June, 2022 the 2NW pit pre-strip had advanced such that first ore had daylighted in the pit floor in blasted stocks, approximately 70Kt of ore has been depleted at the period end.

Table 3: Mt Cattlin Ore Reserve as at 30 June 2022

Category Tonnage
Mt
Grade
% Li2O
Grade
ppm Ta2O5
Contained metal
(‘000) t Li2O
Contained metal
lbs Ta2O5
Variance to 2021
%
Proven % -100%
Probable 2NW only 3.3 1.12 105 37.0 764,000 -30%
  Stockpiles 2.4 0.80 122 19.0 646,000 -20%
Total 5.8 0.98 113 56.0 1,410,000 -28%

Notes: Reported at cut-off grade of 0.4 % Li2O within current mine design. The preceding statements of Ore Reserves conforms to the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (JORC Code) 2012 edition. All tonnages reported are dry metric tonnes. Reported with 17% dilution and 93% mining recovery. Revenue factor US$650/tonne applied. Minor discrepancies may occur due to rounding to appropriate significant figures.

Table 4: Mt Cattlin Ore Reserve as at 31 March 2021

Category Tonnage
Mt
Grade
% Li2O
Grade
ppm Ta2O5
Contained metal
(‘000) t Li2O
Contained metal
lbs Ta2O5
Proven In-situ 0.3 1.36 198 4.1 131,000
Probable In-situ 4.7 1.19 146 55.9 1,512,000
  Stockpiles 3.0 0.80 122 24.0 807,000
Total 8.0 1.04 139 84.0 2,449,000

Notes: Reported at cut-off grade of 0.4 % Li2O within current mine design. The preceding statements of Ore Reserves conforms to the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (JORC Code) 2012 edition. All tonnages reported are dry metric tonnes. Reported with 17% dilution and 93% mining recovery. Revenue factor US$650/tonne applied. Minor discrepancies may occur due to rounding to appropriate significant figures.

A description of the major factors that resulted in changes from the 2021 Ore Reserve to the 2022 Ore Reserve is as follows:

  • Resource model depleted for ore extracted from the completed 2NE pit;
  • An updated 2021 Mineral Resource Estimate and supporting Ore Reserve Study;
  • Decrease in Ore Reserves due to open pit mining and stockpile processing;
  • Decline in grade is due to the mining of higher-grade material in H2 CY21 compared to the life of mine grade; and
  • Reconciliation indicates the now depleted 2NE pit delivered 1.4Mt @1.62% Li2O.

The Ore Reserve does not take into account the infill drilling results from the 2NW deposit and the mine design has not been changed to take into account increase in Mineral Resources due to changes in pit shell. A revised mine design based on an updated Mineral Resource will be undertaken after the completion of the current major drilling programme.

Appropriate assessments and studies have been carried out and include consideration of and modification by realistically assumed mining, metallurgical, economic, marketing, legal, environmental, social and governmental factors. These assessments demonstrate at the time of reporting that extraction could reasonably be justified.

RESOURCE AND RESERVE CONTROLS & GOVERNANCE

Allkem ensures that quoted Mineral Resource and Ore Reserve estimates are subject to internal controls and external review at both project and corporate levels. Mineral Resource and Ore Reserves are estimated and reported in accordance with the 2012 edition of the JORC Code.

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. RPEEE has been tested against a Whittle Optimisation with only the revenue factor changed from USD 900 to 1,100.

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.

This release was authorised by Mr Martin Perez de Solay, CEO and Managing Director of Allkem Limited.

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, 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 30 June 2022 Mt Cattlin Ore Reserve is based on information compiled by Keith Muller, B. Eng. (Mining), M. Eng. (Mining), F.Aus.IMM (CP Mining), a Competent Person who is a Fellow of the Australasian Institute of Mining and Metallurgy. Keith Muller is a full-time employee of Galaxy Resources Pty. Ltd. Keith Muller 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’. Keith Muller consents to the inclusion in this announcement of the matters based on his information in the form and context in which it appears.

The scientific and technical information contained in this announcement has been reviewed and approved by Albert Thamm, as it relates to geology, exploration, drilling, sample preparation, data verification and the depleted Mineral Resource and Keith Muller, BEng Mining, M. Eng. F.Aus.IMM (CP Mining) as it relates to the Mineral Reserve, mining methods and infrastructure; mineral processing, recovery methods, market studies, permitting, environmental and social studies, capital and operating cost estimates and economic analysis.

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 is available at www.allkem.co


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