Exhibit 99.1

Quarterly Activities & Cashflow Report

FOR THE QUARTER ENDED 30 SEPTEMBER 2026

Chilwa Minerals Limited (ASX:CHW, NASDAQ:CHWM) (Chilwa or the Company) reports on its activities for the quarter ended 30 September 2026. Work focused on drilling at Mpyupyu West and Nakombe, metallurgical testing and the mineral sands Scoping Study. The Company completed the SEC review of its Registration Statement on Form F-1 during the quarter. Its US$3.5 million initial public offering closed and Nasdaq trading began after quarter end.

Highlights for the quarter

Heavy Mineral Sands

Rare Earths and Niobium

Ionic Clays

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Corporate

Overview

The quarter’s work centred on drilling and testing at the Company’s Malawi projects. At Mpyupyu West, both sonic rigs worked across the nominal 400 m × 200 m Phase I grid on the 17 km² target. The first sample batches were sent for sink-float assay and per-interval XRF. Diamond drilling continued at Nakombe towards a maiden Mineral Resource estimate, while work continued on the mineral sands Scoping Study.

The Company also completed the SEC review of its proposed US offering and released its FY2026 Annual Financial Report. The IPO closed and Nasdaq trading began in October, after the reporting period. Details are set out under Corporate and Significant events post 30 September 2026.

The Chilwa Alkaline Province is a Cretaceous-age alkaline igneous complex in southern Malawi, hosting multiple REE and niobium deposits alongside Mkango’s Songwe Hill and Lindian’s Kangankunde projects.

Airborne geophysics completed in 2024 and soil geochemistry undertaken in 2025 identified up to 47 interpreted carbonatite and alkaline intrusive targets within the Lake Chilwa licence package. Diamond drilling is testing this exploration pipeline.

Table 1 September quarter 2026 drilling activity summary

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Mineral sands

Mpyupyu West — Phase I drilling confirms the outline of a 17 km² prospect

Phase I reconnaissance sonic drilling at Mpyupyu West continued throughout the quarter. The discovery was first reported on 3 June 2026 and surface panning expanded the target to more than 17 km² on 23 June. By 6 August, 60 holes for 551 metres had been completed, or 22% of the programme. Both sonic rigs were then working at Mpyupyu West following the move from Bimbi Main. By 6 October, drilling had reached 218 holes for 2,292 metres, or 80% of the planned 272-hole programme on a nominal 400 mN × 200 mE grid. Average hole depth was 8.6 metres (ASX announcements 6 August and 9 October 2026).

Figure 1 Mpyupyu West Phase I reconnaissance sonic drill plan — holes completed to 6 October 2026 and planned collars on the nominal 400 mN × 200 mE grid, with the Mpyupyu Dune and Flat resources, Bimbi Southwest and the Nakombe target (ASX announcement 9 October 2026).

Drilling indicates that 63% of the mineralisation is hosted in deeply weathered saprolite, rather than transported aeolian and strandline sands. In this type of deposit, resistant heavy minerals remain as less stable minerals weather and are removed. This can form a laterally extensive near-surface blanket. Deposits of this type have been developed elsewhere in Malawi, including the Kasiya rutile project. At Mpyupyu West, the mineralised horizon begins beneath a thin surface sand unit and is free-dig to saprock.

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Laboratory sink-float assays will determine total heavy mineral content. The first two batches of geological-domain composite samples were shipped internationally during the quarter, with results expected in late October 2026. After receiving the results, the Company expects to report a maiden Exploration Target for Mpyupyu West as defined in the JORC Code.

Figure 2 Representative west–east geological cross section through the Mpyupyu West drilling at 8,295,950 mN (30× vertical exaggeration), showing the interpreted sequence of sand, lateritic silty sand, sandy clay, saprolite and saprock. Geological interpretation only (ASX announcement 9 October 2026).

“Now in the final stretch of the Phase I program, Mpyupyu West is looking less like a discovery and more like a new major component of a mineral sands district. The grid has filled in across more than 17 square kilometres next to our Mpyupyu Dune and Flat deposits, and the free-dig saprolite profile has held from near-surface to saprock, at an average depth of around 8.6 metres, hole after hole. Scale and consistency together are what set this prospect apart.”

— Cadell Buss, Managing Director (9 October 2026)

Bimbi Main

Bimbi Main resource-definition drilling reached 166 holes for 1,843 metres, or 62% of the programme, before the sonic rig moved to Mpyupyu West in July. Drilling at Bimbi Main will resume after the Mpyupyu West Phase I programme is completed.

Mpyupyu Dune and Flat

The Mpyupyu Mineral Resource remains as announced on 19 June 2026 (109.6 Mt at 3.28% THM at a 1% THM cut-off, approximately 89% Measured and Indicated).

Scoping Study & Technical Review Study

TZ Minerals International (TZMI) continued work on the Company’s first Scoping Study. The Study covers Measured and Indicated mineral sands resources on the northern, western and southern shores of Lake Chilwa, including Mpyupyu and Mposa. TZMI visited the site in October 2026. Completion is expected in the December 2026 quarter, along with a Technical Report Summary. The Technical Report Summary is the independent mineral resource and reserve report that the SEC requires mining companies to file under Regulation S-K Subpart 1300 (S-K 1300). Assays from the completed Northern Shore sonic programme at Halala, Namanja West and Nkotamo were received, and a revised Mineral Resource estimate is being prepared. Head characterisation and processing trials on Mpyupyu Dune and Flats composites reached the separation of magnetic and non-magnetic products. The work distinguishes Mpyupyu deposit mineralogy, product recovery and quality parameters from those at Mposa.

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Discussions with Mota-Engil Malawi continued on dry-port capacity at Lilongwe and the rail route to Nacala in Mozambique.

Table 3 Chilwa Project minerals portfolio — applications and critical mineral designation

Rare earths and niobium

Up to three diamond rigs drilled the Nakombe alkaline-syenite intrusion during the quarter: the Mota-Engil LF90D rig and two Agua Terra/Infinity CS14 rigs. The programme builds on the conceptual Exploration Target announced on 15 June 2026 and the mineralised intercepts reported earlier in MPYDD006, MPYDD007, MPYDD009 and MPYDD015. Approximately 5,722 metres had been completed across the Nakombe North and South targets by the end of September 2026. Rig availability and difficult drilling conditions on the eastern side of the target constrained progress.

QEMSCAN mineralogical composites were submitted during the quarter, with results expected in mid-November 2026. Planning continued for an infill drilling grid at nominal 80–100 metre spacing to support a maiden Mineral Resource estimate. Soil sampling extended to the Halala (Chikala North) anomaly for pXRF screening, with Mposa West and Namanja to follow. No new Exploration Results for Nakombe were reported during the quarter. Assays for holes drilled since the June 2026 announcements are pending and will be reported in accordance with the JORC Code when received.

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Table 4 Nakombe Exploration Target — tonnage and grade ranges by mineralised domain (ASX announcement 15 June 2026)

Cautionary statement: the Exploration Target described above is conceptual in nature. There has been insufficient exploration to estimate a Mineral Resource, and it is uncertain whether further exploration will result in the estimation of a Mineral Resource. The Exploration Target is not being reported as part of any Mineral Resource or Ore Reserve, and it should not be assumed that all or any part of the Exploration Target will be confirmed as a Mineral Resource through further exploration.

Ionic clays

ANSTO tested 22 Mposa basal-clay samples using ammonium sulphate leaching during the quarter to assess whether the rare earths occur in a recoverable ionic-adsorption form. This follows the June 2026 report of 200 samples averaging 525 ppm TREO across an approximately 8 km corridor. A subset of samples with elevated dysprosium and yttrium has progressed to more aggressive acid-leach testing. Sonic Rig 2 also completed five holes to approximately 30 metres beneath Mpyupyu Flat to sample the clay profile. These samples will be screened by pXRF, using yttrium as an indicator of TREO content, before ICP-MS assay and desorption testing. Clays above the Mpyupyu West saprolite will also be analysed because of the different deposit style.

Corporate

US listing — Nasdaq

The SEC declared the Company’s Registration Statement on Form F-1 effective on 29 September 2026 (US time). The Company had filed the Registration Statement on 9 July and responded to three rounds of SEC comments during the quarter. An ASX trading halt began on 29 September pending pricing. The IPO was priced on 30 September (US time) and announced to ASX on 1 October, when the halt was lifted.

Maxim Group LLC managed the underwritten IPO as sole book-running manager. The Company issued 625,000 ADSs at US$5.60 each, raising US$3.5 million (A$5.0 million) before underwriting discounts and offering expenses. Each ADS represents 10 ordinary shares, bringing the underlying share issue to 6,250,000 shares. Each ADS carried one five-year warrant exercisable at US$5.60 per ADS. The underwriter also received 31,250 representative warrants exercisable at US$7.00 per ADS, or one for every 20 ADSs sold. Nasdaq trading under CHWM began on 1 October 2026 and the offering closed on 2 October. Net proceeds of US$3,143,118 (approximately A$4.49 million) were received on 5 October. The securities were issued within the Company’s Listing Rule 7.1 capacity. An Australian prospectus was lodged with ASIC on 1 October to satisfy on-sale requirements. Directors and the major shareholder, together holding 34,415,866 ordinary shares, entered six-month lock-up agreements, facilitated by ASIC relief.

Maxim partially exercised the over-allotment option on 16 October 2026. It purchased 56,834 ADSs, representing 568,340 ordinary shares, at US$5.59 per ADS. Gross proceeds were US$317,702 and net proceeds were US$292,286. This brought total gross proceeds from the US offering to approximately US$3.82 million (A$5.45 million). Up to 35,166 ADSs and 92,000 warrants remain available under the option until 16 November 2026 (ASX announcement 19 October 2026).

“Listing on Nasdaq is Chilwa’s most significant milestone since joining the ASX. It provides direct access to the world’s deepest capital market for critical minerals and positions us before investors, end-users and agencies focused on rebuilding supply chains outside China. It also enables us the ability to pursue US Government development grants, the first of which we have already applied for.”

— Cadell Buss, Managing Director (1 October 2026)

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Table 5 Capital structure at the date of this report

As a Nasdaq-listed foreign private issuer the Company now furnishes its ASX announcements to the SEC on Form 6-K and will file an annual report on Form 20-F for the year ending 30 June 2027.

FY2026 Annual Financial Report

The Company released its audited FY2026 Financial Report, Appendix 4G and Corporate Governance Statement on 30 September 2026. The Group recorded a loss of $6,881,603, reflecting exploration expenditure and Nasdaq listing costs. At 30 June, it held cash of $1,072,093 and a $30,000 restricted term deposit, exploration and evaluation assets of $26,026,776 and net assets of $25,983,040. Note 1(a) explains the restatement of the FY2025 comparatives. The auditor’s report includes an emphasis of matter on that restatement and a material uncertainty related to going concern paragraph. The IPO contemplated in the Directors’ going concern assessment subsequently closed on 2 October 2026.

Cash position and funding

Quarter-end cash was $5k: bank balances and petty cash of $12k, plus a $30k term deposit securing the corporate card facility, less a $37k operating-account overdraft. The quarter’s net operating outflows were $381k, exploration and equipment payments were $559k, and Nasdaq IPO transaction costs were $188k. Receipts included $32k from option exercises and $28k from Lindian Resources for assay work via the Zalewa laboratory.

IPO net proceeds of approximately A$4.49 million were received on 5 October 2026 and used first to settle accrued creditors. Adding those proceeds to quarter-end cash gives pro forma cash of approximately $4.5 million, before the over-allotment proceeds received on 16 October. Luso Global Mining B.V., the major shareholder, had provided financial support of up to $1,500,000 under its letter dated 30 September 2026, pending completion of the IPO. No funds were drawn and the commitment lapsed on 2 October when the IPO closed. Appendix 5B items 8.8.1–8.8.3 discuss the funding outlook.

Annual General Meeting

The AGM will be held in Perth at 3.00pm (AWST) on Friday, 27 November 2026 (ASX announcement 28 October 2026). The Notice of Meeting was released to ASX on 28 October 2026. It includes resolutions to ratify the Nasdaq offering securities under Listing Rule 7.4, restoring placement capacity under Listing Rule 7.1, and to approve additional capacity under Listing Rule 7.1A.

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Africa Down Under 2026

Chilwa was a Major Sponsor of the Africa Down Under conference, held in Perth from 2 to 4 September 2026, and was invited to attend the Ministerial Dinner. Cadell Buss presented during the Malawi session on 2 September, with the presentation released to ASX on the same day. Cadell Buss, Graham Hewson and Keith Byrne also attended the Malawi Government luncheon on 4 September. Meetings during the conference focused on the Nasdaq listing, US Government engagement and potential business relationships in Malawi, including banking and equipment finance.

Figure 3 Managing Director Cadell Buss meeting in Malawi with the Malawi Government delegation introduced at the at Africa Down Under conference in Perth, September 2026.

Figure 4 Managing Director Cadell Buss with the Hon. Thoko Tembo MP, Malawi Minister of Mining

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Investor relations and government engagement

The Company met US federal agencies in August 2026 and applied for US Government development funding for the Nakombe niobium programme in September. Cadell Buss presented to agencies in Washington DC in October. After the Nasdaq listing, the Company appointed a US investor relations adviser.

The Company continued discussions with Malawi’s Ministry of Mining and the Mining and Minerals Regulatory Authority. After quarter end, the Ministry released a draft Mines and Minerals (Amendment) Bill and draft Value Addition Regulations for consultation. Chilwa lodged a submission on 9 October supporting the value-addition objectives and proposing staged implementation as local processing capacity develops. The Company is coordinating its response with other ASX-listed companies operating in Malawi.

Laboratory services and community engagement

The Zalewa sample preparation laboratory received its first third-party payments of $27,564 under the Lindian Resources Limited (ASX:LIN) arrangement announced on 28 May 2026. Commissioning continued at the Company’s Zomba assay laboratory, with pulverising equipment purchased during the quarter. Community work included landowner liaison and drilling-access arrangements at Mpyupyu West and Nakombe, and briefings for authorities in Machinga, Zomba and Phalombe Districts. A competitive tender for the mine Environmental and Social Impact Assessment (ESIA) consultant was completed during the quarter. RSK Environment (East Africa) Ltd was appointed in October 2026.

Environment, social and community

HSEC

Routine safety controls, including on-site alcohol testing, continued across all drilling operations. In a significant step for the Company, the HSEC function was brought in-house during the quarter, with Chilwa’s first Malawi-based HSEC Manager commencing in September. This strengthens the Company’s on-the-ground capacity to manage environmental and social performance and community relationships as the project advances.

Community investment

Between June and July 2026, Chilwa supported repairs to a 200-metre section of the Kachulu road (S143, Mpyupyu road). The works were delivered using locally sourced materials and labour, with residents from the surrounding area employed directly, providing household income and practical skills while keeping costs and the environmental footprint low. The improved road provides better access for transport, trade and emergency services, as well as for the Company’s field crews. Rehabilitation of the T/A Lamusi Community Hall near the Mpyupyu deposit commenced in June 2026 and is progressing well.

Local employment

Chilwa employs approximately 50 people in Malawi, predominantly from communities near the project in the Machinga, Zomba and Phalombe districts. This includes HSEC staff, geo-technicians and drill assistants. In addition, around 100 casual workers from local communities were engaged during the quarter in site rehabilitation, security, road works and community water supply activities, with women participating in the water supply work.

Environment

Sonic and diamond drill sites continue to be progressively rehabilitated following sampling

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Significant events post 30 September 2026

The following events occurred after the end of the quarter and up to the date of this report.

Completion of the US initial public offering and Nasdaq listing

Nasdaq trading began on 1 October 2026, the IPO closed on 2 October and net proceeds were received on 5 October. The US prospectus was released to ASX on 5 October. Offering terms and proceeds are set out under US listing — Nasdaq and in Table 5.

Over-allotment option

Maxim partially exercised the over-allotment option on 16 October 2026 (New York time). The proceeds and remaining option terms are set out under US listing — Nasdaq and in Table 5 (ASX announcement 19 October 2026).

Exercise of options

On 12 October 2026 the Company issued 98,250 ordinary shares following the exercise of 48,251 options at $0.25 and 49,999 options at $0.40. The $32,062 exercise proceeds were received in September and appear in Appendix 5B item 3.3. Ordinary shares on issue following these allotments totalled 104,922,682 (Appendix 2A and section 708A notice, 12 October 2026).

Mpyupyu West drilling update

The 9 October 2026 ASX update reported Mpyupyu West drilling and sample shipments to 6 October. The Mineral sands section sets out the results and expected assay timing.

Other matters

The Notice of AGM was released to ASX on 28 October 2026. The Company also entered an insurance premium funding arrangement after quarter end (Appendix 5B item 7.6). Apart from the transactions described above, no capital was raised or securities issued between 30 September and the report date. No new litigation, impairment triggers or changes to tenement interests or Malawian mineral tenure arose during that period.

Additional ASX information

ASX Listing Rule 5.3.1 — During the quarter, the Company made payments of $0.559 million for exploration activities on the Project (Appendix 5B items 2.1(c) and 2.1(d)), comprising $0.521 million of capitalised exploration and evaluation expenditure (drilling, assaying, geological consultants, environmental studies, the Scoping Study and site operations) and $0.038 million for plant and equipment supporting exploration (principally laboratory and computer equipment).

ASX Listing Rule 5.3.2 — There were no funds spent on mining production and development activities for the quarter.

ASX Listing Rule 5.3.3 — The schedule of mineral tenements and changes in interests is shown in Table 8. There were no changes to the Company’s tenement interests during the quarter.

ASX Listing Rule 5.3.4 — Reporting under a use of funds statement in a prospectus does not apply to the Company this quarter.

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ASX Listing Rule 5.3.5 — Table 6 provides a description and explanation of the payments made to related parties of the Company and their associates, which are included in Appendix 5B item 6 for the quarter.

Table 6 Related party payments

No cash payments were made to Mota-Engil group entities during the quarter. Amounts payable to the Mota-Engil group for services provided during the quarter and unpaid at quarter end are included in trade and other payables and accruals (no cash flow in the quarter).

Table 7 September quarter ASX announcements

Table 8 Schedule of tenement interests

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Table 9 Consolidated JORC Mineral Resources — all deposits, at 1.0% THM cut-off, as at 19 June 2026 (unchanged during the quarter)

Mineral Resources for all deposits are unchanged from those reported in the announcements of 8 December 2025 and 19 June 2026 and the June 2026 quarterly report. Across all deposits, approximately 85% of the total Mineral Resource is classified in the Measured and Indicated categories. The Nakombe Exploration Target is conceptual in nature and is not a Mineral Resource.

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Compliance statement

The information in this announcement that relates to previously reported Exploration Results, Exploration Targets and Mineral Resource estimates was prepared and first disclosed under the JORC Code (2012 Edition). The information was extracted from the Company’s previous ASX announcements as follows:

All of the above announcements are available on the Company’s website at https://www.chilwaminerals.com/. The Company confirms that it is not aware of any new information or data that materially affects the information included in the original announcements and, in the case of reporting of Mineral Resources, that all material assumptions and technical parameters underpinning the estimates in the relevant market announcements continue to apply and have not materially changed. The Company confirms that the form and context in which any Competent Person’s findings are presented have not been materially modified from the original market announcements. The Exploration Target referred to above is conceptual in nature; there has been insufficient exploration to estimate a Mineral Resource and it is uncertain whether further exploration will result in the estimation of a Mineral Resource. No drilling Exploration Results, assay results or heavy mineral grades are reported in this announcement for Mpyupyu West; visual estimates of heavy-mineral content from on-site panning and pXRF readings are used for geological domaining and programme planning only.

Looking ahead

The next stages of work are:

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Forward looking statements

This ASX release may contain certain “forward-looking statements” which may be based on forward-looking information that are subject to a number of known and unknown risks, uncertainties, and other factors that may cause actual results to differ materially from those presented here. Where the Company expresses or implies an expectation or belief as to future events or results, such expectation or belief is expressed in good faith and believed to have a reasonable basis. Readers should not place undue reliance on forward-looking information. The Company does not undertake any obligation to release publicly any revisions to any forward-looking statement to reflect events or circumstances after the date of this ASX release, or to reflect the occurrence of unanticipated events, except as may be required under applicable securities laws.

Disclaimer: No representation or warranty, express or implied, is made by the Company that the material contained in this announcement will be achieved or proved correct. Except for statutory liability which cannot be excluded, each of the Company, its directors, officers, employees, advisors and agents expressly disclaims any responsibility for the accuracy, fairness, sufficiency or completeness of the material contained in this announcement.

– ENDS –

This announcement has been authorised for release by the Managing Director.

For further information contact:

Cadell Buss

Founder and Managing Director

cbuss@chilwaminerals.com.au

Rule 5.5

Appendix 5B

Mining exploration entity or oil and gas exploration entity
quarterly cash flow report

Appendix 5B

Mining exploration entity or oil and gas exploration entity quarterly cash flow report

Note: item 5.2 comprises a $30,000 term deposit securing the Company’s corporate credit card facility. Item 5.3 is the overdrawn balance of the Company’s NAB operating account at 30 September 2026, repaid on 6 October 2026 from the IPO proceeds; the account has no formal overdraft facility.

Note: if any amounts are shown in items 6.1 or 6.2, your quarterly activity report must include a description of, and an explanation for, such payments. See Table 6 of the activities report.

Appendix 5B

Mining exploration entity or oil and gas exploration entity quarterly cash flow report

Note: if the entity has reported positive relevant outgoings (ie a net cash inflow) in item 8.3, answer item 8.7 as “N/A”. Otherwise, a figure for the estimated quarters of funding available must be included in item 8.7.

Appendix 5B

Mining exploration entity or oil and gas exploration entity quarterly cash flow report

Compliance statement

Notes