September 2023 Quarterly Activities Report

Castillo Copper Limited (LSE and ASX: CCZ), a base metal explorer primarily focused on copper across Australia and Zambia, is pleased to present shareholders its latest quarterly report for the period 1 July 2023 to 30 September 2023.

HIGHLIGHTS:

Cangai copper mine

• Updated JORC (2012) compliant Mineral Resource Estimate for Cangai Copper Mine at 4.4Mt @ 2.5% Cu inferred insitu and 0.2Mt @ 1.35% Cu indicated from historic stockpiles for ~114kt contained copper metal; augmented further by zinc, gold, and silver credits1

INTERIM EXECUTIVE DIRECTOR APPOINTMENT

• Post the review period, the Board appointed Mr Jack Sedgwick as interim Executive Director
• Mr Sedgwick's mandate is to undertake an asset review of the current portfolio, re-shape priorities then update the group's strategic intent

ACTIVITIES REPORT

An overview of key events follows:

DEVELOPMENT WORK

Castillo has four properties comprising the NWQ Copper Project in Mt Isa's copper-belt in Queensland, the BHA Project near Broken Hill's world class silver-zinc-lead deposit in NSW, the historic Cangai Copper Mine in NSW and several assets across Zambia's copper-belt.

CANGAI COPPER MINE, NSW

On 25 July 2023, Castillo's geology team, working in conjunction with a specialist geological consultancy, produced an updated JORC (2012) compliant Mineral Resource Estimate (MRE) for the Cangai Copper Mine at:

• 4.4Mt @ 2.5% Cu inferred insitu and 0.2Mt @ 1.35% Cu indicated from historic stockpiles for ~114kt contained copper metal; augmented further by zinc, gold, and silver credits (Table 1)1.

Table 1: Cangai Copper Mine Resource Tonnages

Notes:

• All resource tonnages rounded to the nearest 1,000 tonnes
• Refer to JORC Table 1 for details on data and estimation
• Insitu tonnages calculated as a guide only, no recovery factor, loss or dilution considered

Source: CCZ Geology Team

In calculating the updated MRE from the 2017 work (MRE: 3.3Mt @ 3.35% Cu for 108,000t4), the geology team factored in reverse circulation and diamond core drilling campaigns undertaken across 2017-18 and used more conservative assumptions to boost the confidence in the revised 2023 MRE. The geology team noted several encouraging observations that underpins significant exploration potential for the Cangai Copper Mine, including:

• The underlying orebody - which commences from surface - is not fully defined, as it remains open to the east, south-east and down dip.
• There are several sizeable downhole electromagnetic (DHEM) conductors, proximal to the line of lode, that can potentially extend known mineralisation along strike.
• With the revised 2023 MRE enhancing the Cangai Copper Mine's resource size, the Board is highly optimistic Castillo can realise value for shareholders from this historical producing asset.

Exploration potential

A key positive for the Cangai Copper Mine is the copper orebody commences from surface. More encouragingly, the full extent of the underlying copper orebody remains undetermined, as it remains open to the east, south-east and down dip. As shown in Figure 1, there are several sizeable DHEM conductors1, which are north and south of the line of lode, that can potentially extend known mineralisation along strike.

Figure 1: DHEM conductors at Cangai Copper Mine

POST PERIOD EVENT

On 9 October 2023, the Board announced the appointment of Mr Jack Sedgwick as interim Executive Director2, following the departure of former Managing Director, Dr Dennis Jensen. Mr Sedgwick's mandate is to undertake a thorough asset review, re-shape priorities then update the group's strategic intent3.

PAYMENTS TO, OR TO AN ASSOCIATE OF, A RELATED PARTY OF THE ENTITY DURING QUARTER DURING THE QUARTER

$172,000 was paid to related parties of Castillo relating to executive director salary and non-executive director fees.

Table 2: Summary of the exploration expenditure incurred during the quarter

The group is listed on the LSE and ASX under the ticker "CCZ."

References

• Updated Mineral Resource Estimate for Cangai Copper Mine announcement 25 July 2023
• Board Changes announcement 10 October 2023
• Strategic Asset Portfolio Review Underway announcement 17 October 2023
• High-grade JORC Inferred Resource at Cangai Copper Mine Exceeds Expectations announcement 6 September 2017

APPENDIX A: Key PROJECTS

Figure 2: West and East Zone - BHA Project, Broken Hill Region (Source: CCZ Geology Team)

Figure 3: Zambia Copper-Belt Projects (Source: CCZ Geology Team)

Figure 4: NWQ Copper Project, Mt Isa Region (Source: CCZ Geology Team)

APPENDIX B: Interest in mining tenements held

Table 3: Jackaderry (Cangai), New England Orogen in NSW

Table 4: Broken Hill, located within a 20km radius of Broken Hill in NSW

Table 5: Mt Oxide, Mt Isa region in North West Queensland

Appendix 5B

Mining exploration entity or oil and gas exploration entity

quarterly cash flow report

Name of entity

Castillo Copper Ltd

• entities
• tenements
• property, plant and equipment
• investments
• other non-current assets

1 Comprises director's fees for the quarter. 2 Comprises consulting fees paid to the Managing Director and exploration expenditure paid to Field Crew Pty Ltd, a related entity of director David Drakeley.

Answer: N/A

Answer: N/A

Answer: N/A

Compliance statement

2 This statement gives a true and fair view of the matters disclosed.

Date: 30 October 2023

Authorised by: The Board of Directors

(Name of body or officer authorising release - see note 4)

Notes