19 December 2023

ARAGUAIA PROJECT UPDATE

HIGHLIGHTS:

· Demobilization well advanced with two critical construction activities continuing to progress

· Consolidated cash position of US$42m as of December 15^th 2023 which is expected to last until the end of January 2024

· Positive discussions remain ongoing between lenders and cornerstone shareholders with regard to commercial terms for an interim financing solution to extend this period

· The Company and independent consultants continue to review the outstanding Project capital expenditure and schedule re-estimate, necessary to implement a full funding solution

Horizonte Minerals Plc (AIM/TSX: HZM) ("Horizonte" or the "Company") the nickel development company, announces that discussions with the Company's cornerstone shareholders on an interim financing package continue to progress. Discussions were initiated to provide sufficient liquidity for the Company to complete the required re-estimation and risk reduction work necessary to implement a full funding solution for its flagship Araguaia Nickel Project ("Araguaia" or "the Project").

LINE 1 OPERATIONAL & FINANCING UPDATE

As announced on 14 November 2023, the Company reduced construction activities at Araguaia, progressing only critical work streams in order to manage the Company's liquidity, whilst continuing discussions with the Company's cornerstone shareholders and senior lenders. Based on the cash preservation measures undertaken to date, and ongoing conversations with suppliers, the Company now estimates to have sufficient working capital until the end of January 2024. If successful, the discussions with the cornerstone shareholders and senior lenders should avail further interim funding to extend this period.

As of 15 December 2023, the Group had a cash position of US$42 million, of which US$19 million is held in secured accounts relating to Araguaia's project financing and US$16 million is segregated for the development of Vermelho, with the balance of US$7 million spread amongst other entities for the ongoing running of the Group.

The Company's cornerstone shareholders and senior lenders are continuing to undertake their respective due diligence as part of a full funding solution, which includes working with the Company and independent consultants who are undertaking a review of the outstanding Project capital expenditure and schedule. It is expected that this due diligence process and independent review will be finalised in Q1 2024, with a full funding solution targeted for early Q2 2024.

During this slowdown period, the Company continues to advance construction of two workstreams, the Water Storage Reservoir and the 230kV powerline, both critical components of Rotary Kiln Electric Furnace (RKEF) operations, while maintaining a strong focus on safety and cash preservation measures.

In conjunction with the above, the Company continues to be focussed on minimizing the impacts of the deceleration and demobilization of construction activities on site, as well as taking the necessary actions to secure a safe and sustainable resumption of construction activities following the slow down.

LINE 2 FEASIBILITY STUDY

Due to the ongoing review of the outstanding Project capital expenditure and schedule for Araguaia Line 1, the Line 2 Feasibility Study has been placed on hold given the intrinsic relationship between Araguaia Line 1 and Line 2.

This announcement contains inside information for the purposes of Article 7 of EU Regulation 596/2014, as retained in the UK pursuant to the European Union (Withdrawal) Act 2018.

For further information, visit www.horizonteminerals.com or contact:

ABOUT HORIZONTE MINERALS

Horizonte Minerals Plc (AIM/TSX: HZM) is developing two 100%-owned, Tier 1 projects in Pará state, Brazil - the Araguaia Nickel Project and the Vermelho Nickel-Cobalt Project. Both projects are high-grade, low-cost, with low carbon emission intensities and are scalable. Araguaia is under construction and when fully ramped up with both Line 1 and Line 2, is forecast to produce 29,000 tonnes of nickel per year. Vermelho is at feasibility study stage and is expected to supply nickel to the critical metals market. Horizonte's combined production profile of over 60,000 tonnes of nickel per year positions the Company as a globally significant nickel producer. Horizonte's top three shareholders are La Mancha Investments S.à r.l., Glencore Plc and Orion Resource Partners LLP.

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING INFORMATION

Except for statements of historical fact relating to the Company, certain information contained in this press release constitutes "forward-looking information" under Canadian securities legislation. Forward-looking information includes, but is not limited to, the ability of the Company to complete any planned acquisition of equipment, statements with respect to the potential of the Company's current or future property mineral projects; the ability of the Company to complete a positive feasibility study regarding the second RKEF line at Araguaia on time, or at all, the ability of the Company to complete a positive feasibility study regarding the Vermelho Project on time, or at all, the success of exploration and mining activities; cost and timing of future exploration, production and development; the costs and timing for delivery of the equipment to be purchased, the estimation of mineral resources and reserves and the ability of the Company to achieve its goals in respect of growing its mineral resources; the realization of mineral resource and reserve estimates and achieving production in accordance with the Company's potential production profile or at all. Generally, forward-looking information can be identified by the use of forward-looking terminology such as "plans", "expects" or "does not expect", "is expected", "budget", "scheduled", "estimates", "forecasts", "intends", "anticipates" or "does not anticipate", or "believes", or variations of such words and phrases or statements that certain actions, events or results "may", "could", "would", "might" or "will be taken", "occur" or "be achieved". Forward-looking information is based on the reasonable assumptions, estimates, analysis and opinions of management made in light of its experience and its perception of trends, current conditions and expected developments, as well as other factors that management believes to be relevant and reasonable in the circumstances at the date that such statements are made, and are inherently subject to known and unknown risks, uncertainties and other factors that may cause the actual results, level of activity, performance or achievements of the Company to be materially different from those expressed or implied by such forward-looking information, including but not limited to risks related to: the inability of the Company to complete any planned acquisition of equipment on time or at all, the ability of the Company to complete a positive feasibility study regarding the implementation of a second RKEF line at Araguaia on the timeline contemplated or at all, the ability of the Company to complete a positive feasibility study regarding the Vermelho Project on the timeline contemplated or at all, exploration and mining risks, competition from competitors with greater capital; the Company's lack of experience with respect to development-stage mining operations; fluctuations in metal prices; uninsured risks; environmental and other regulatory requirements; exploration, mining and other licences; the Company's future payment obligations; potential disputes with respect to the Company's title to, and the area of, its mining concessions; the Company's dependence on its ability to obtain sufficient financing in the future; the Company's dependence on its relationships with third parties; the Company's joint ventures; the potential of currency fluctuations and political or economic instability in countries in which the Company operates; currency exchange fluctuations; the Company's ability to manage its growth effectively; the trading market for the ordinary shares of the Company; uncertainty with respect to the Company's plans to continue to develop its operations and new projects; the Company's dependence on key personnel; possible conflicts of interest of directors and officers of the Company, and various risks associated with the legal and regulatory framework within which the Company operates, together with the risks identified and disclosed in the Company's disclosure record available on the Company's profile on SEDAR at www.sedar.com, including without limitation, the annual information form of the Company for the year ended December 31, 2022, and the Araguaia and Vermelho Technical Reports available on the Company's website https://horizonteminerals.com/. Although management of the Company has attempted to identify important factors that could cause actual results to differ materially from those contained in forward-looking information, there may be other factors that cause results not to be as anticipated, estimated or intended. There can be no assurance that such statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements.