THIS ANNOUNCEMENT AND THE INFORMATION CONTAINED THEREIN (this "Announcement"), IS RESTRICTED AND IS NOT FOR PUBLICATION, RELEASE, DISTRIBUTION OR FORWARDING, DIRECTLY OR INDIRECTLY, IN WHOLE OR IN PART, IN OR INTO THE UNITED STATES, AUSTRALIA, JAPAN, THE REPUBLIC OF SOUTH AFRICA OR ANY OTHER JURISDICTION IN WHICH SUCH PUBLICATION, RELEASE OR DISTRIBUTION WOULD BE UNLAWFUL.

FURTHER, THIS ANNOUNCEMENT IS FOR INFORMATION PURPOSES ONLY AND DOES NOT CONSTITUTE OR FORM ANY PART OF AN OFFER TO SELL OR ISSUE, OR A SOLICITATION OF AN OFFER TO BUY, SUBSCRIBE FOR OR OTHERWISE ACQUIRE ANY SECURITIES IN THE UNITED STATES, AUSTRALIA, JAPAN, THE REPUBLIC OF SOUTH AFRICA OR IN ANY OTHER JURISDICTION IN WHICH SUCH OFFER OR SOLICITATION WOULD BE UNLAWFUL OR TO ANY PERSON TO WHOM IT IS UNLAWFUL TO MAKE SUCH OFFER OR SOLICITATION. NO PUBLIC OFFERING OF THE FUNDRAISE SHARES IS BEING MADE IN ANY SUCH JURISDICTION. ANY FAILURE TO COMPLY WITH THESE RESTRICTIONS MAY CONSTITUTE A VIOLATION OF THE SECURITIES LAWS OF SUCH JURISDICTIONS. PLEASE SEE THE IMPORTANT NOTICES AT THE END OF THIS ANNOUNCEMENT.

THIS ANNOUNCEMENT IS NOT FOR PUBLICATION OR DISTRIBUTION, DIRECTLY OR INDIRECTLY, IN OR INTO THE UNITED STATES OF AMERICA.  THIS ANNOUNCEMENT IS NOT AN OFFER OF SECURITIES FOR SALE INTO THE UNITED STATES.  THE SECURITIES REFERRED TO HEREIN HAVE NOT BEEN AND WILL NOT BE REGISTERED UNDER THE U.S. SECURITIES ACT OF 1933, AS AMENDED, AND MAY NOT BE OFFERED OR SOLD IN THE UNITED STATES, EXCEPT PURSUANT TO AN APPLICABLE EXEMPTION FROM REGISTRATION.  NO PUBLIC OFFERING OF SECURITIES IS BEING MADE IN THE UNITED STATES.

Terms used in this announcement have the same meaning given to them as defined in the Fundraise Announcement.

For immediate release

12 October 2022

Horizonte Minerals Plc

("Horizonte", the "Company" or the "Group")

Posting of Circular and Notice of General Meeting

Horizonte Minerals Plc (AIM: HZM, TSX: HZM) announces that, further to the announcement made on 4 October 2022 (the "Fundraise Announcement") in relation to the proposed fundraise of approximately US$80 million (the "Fundraise") and the proposed admission of the Company's enlarged share capital to AIM and the Toronto Stock Exchange (the "TSX"), a shareholder circular (the "Circular") relating to the Fundraise will be published today and will be filed on the Company's profile on SEDAR and mailed to shareholders on 12 October 2022. The Company has applied to list the new ordinary shares on the TSX and application will be made for the new ordinary shares to also be admitted to trading on AIM. Listing will be subject to approval by the TSX and the Company fulfilling all of the requirements of the TSX. It is expected that TSX and AIM Admission will become effective on or around 8 November 2022.

General Meeting

The Circular includes a Notice of General Meeting convening a general meeting to be held at the offices of Horizonte Minerals plc, Rex House, 4-12 Regent St, London, SW1Y 4RG, United Kingdom at 11.30 a.m. on 4 November 2022 (the "General Meeting").

The Circular is also available via the Company's website: https://horizonteminerals.com/, and will be filed and available on the Company's profile on SEDAR at www.SEDAR.com.

Enquiries:

IMPORTANT NOTICES

This Announcement is not for publication or distribution, directly or indirectly, in or into the United States of America. This Announcement is not an offer of securities for sale into the United States. The securities referred to herein have not been and will not be registered under the United States Securities Act of 1933, as amended (the "U.S. Securities Act"), or with any securities regulatory authority of any state or jurisdiction of the United States, and may not be offered or sold in the United States, except pursuant to an applicable exemption from the registration requirements of the U.S. Securities Act and in compliance with any applicable securities laws of any state or other jurisdiction of the United States. No public offering of the Placing Shares is being made in the United States.

THIS ANNOUNCEMENT IS FOR INFORMATION PURPOSES ONLY AND DOES NOT CONSTITUTE OR FORM ANY PART OF AN OFFER TO SELL OR ISSUE, OR A SOLICITATION OF AN OFFER TO BUY, SUBSCRIBE FOR OR OTHERWISE ACQUIRE ANY SECURITIES IN THE UNITED STATES, AUSTRALIA, THE REPUBLIC OF SOUTH AFRICA, JAPAN OR ANY OTHER JURISDICTION IN WHICH SUCH OFFER OR SOLICITATION WOULD BE UNLAWFUL OR TO ANY PERSON TO WHOM IT IS UNLAWFUL TO MAKE SUCH OFFER OR SOLICITATION. NO PUBLIC OFFERING OF THE FUNDRAISE SHARES IS BEING MADE IN ANY SUCH JURISDICTION. ANY FAILURE TO COMPLY WITH THESE RESTRICTIONS MAY CONSTITUTE A VIOLATION OF THE SECURITIES LAWS OF SUCH JURISDICTIONS.

This Announcement is not for public release, publication or distribution, in whole or in part, directly or indirectly, in or into the United States, Australia, the Republic of South Africa, Japan or any other jurisdiction in which such release, publication or distribution would be unlawful.

No action has been taken by the Company, the Joint UK Bookrunners, the Canadian Agents or any of their respective affiliates, or any of its or their respective directors, officers, partners, employees, advisers and/or agents (collectively, "Representatives") that would permit an offer of the Placing Shares or possession or distribution of this Announcement or any other publicity material relating to such Placing Shares in any jurisdiction where action for that purpose is required. Persons receiving this Announcement are required to inform themselves about and to observe any restrictions contained in this Announcement. Persons (including, without limitation, nominees and trustees) who have a contractual or other legal obligation to forward a copy of this Announcement should seek appropriate advice before taking any action. Persons distributing any part of this Announcement must satisfy themselves that it is lawful to do so.

This Announcement is directed at and is only being distributed to: (a) persons in member states of the European Economic Area who are "qualified investors", as defined in Article 2(e) of the Prospectus Regulation (Regulation (EU) 2017/1129) (the "Prospectus Regulation") ("Qualified Investors"), (b) persons in the United Kingdom, who are qualified investors, being persons falling within the meaning of Article 2(e) of Prospectus Regulation (EU) 2017/1129 as it forms part of domestic law by virtue of the European Union (Withdrawal) Act 2018 (the " UK Prospectus Regulation"), and who (i) have professional experience in matters relating to investments who fall within the definition of "investment professionals" in Article 19(5) of the Financial Services and Markets Act 2000 (Financial Promotion) Order 2005, as amended (the "Order") or are high net worth companies, unincorporated associations or partnerships or trustees of high value trusts as described in Article 49(2)(a) to (d) of the Order and (ii) are Qualified Investors, or (c) otherwise, persons to whom it may otherwise lawfully be communicated (each such person in (a), (b) and (c), a "Relevant Person"). No other person should act on or rely on this Announcement and persons distributing this Announcement must satisfy themselves that it is lawful to do so. By accepting the terms of this Announcement, you represent and agree that you are a Relevant Person. This Announcement must not be acted on or relied on by persons who are not Relevant Persons. Any investment or investment activity to which this Announcement or the Placing relates is available only to Relevant Persons and will be engaged in only with Relevant Persons.

This Announcement is not being distributed by, nor has it been approved for the purposes of section 21 of the Financial Services and Markets Act 2000, as amended ("FSMA") by, a person authorised under FSMA. This Announcement is being distributed and communicated to persons in the United Kingdom only in circumstances in which section 21(1) of FSMA does not apply.

No offering document or prospectus will be made available in any jurisdiction in connection with the matters contained or referred to in this Announcement or the Placing and no such prospectus is required (in accordance with either the Prospectus Regulation or the UK Prospectus Regulation) to be published.

This Announcement is not for publication or distribution, directly or indirectly, in or into the United States of America. This Announcement is not an offer for sale into the United States. The securities referred to herein have not been and will not be registered under U.S. Securities Act of 1933, as amended, and may not be offered or sold in the United States except pursuant to an applicable exemption from registration. No public offering is being made in the United States or elsewhere.

Cautionary Statements Regarding Forward-Looking Information

Certain statements in this Announcement are forward-looking statements with respect to the Company's expectations, intentions and projections regarding its future performance, strategic initiatives, anticipated events or trends and other matters that are not historical facts and which are, by their nature, inherently predictive, speculative and involve risks and uncertainty because they relate to events and depend on circumstances that may or may not occur in the future. All statements that address expectations or projections about the future, including statements about expected growth in nickel global demand, production potential, the results of the feasibility and pre-feasibility studies, including, without limitation, expected NPV, IRR, construction period, pay back period, mine life, expected costs, cash generation  and operating performance and other metrics, the Company's expectations with respect to its financing package (including without limitation, ability to draw down under such funding package) and the timing of commencement of construction for Araguaia, the intended use of proceeds from the proposed Fundraise, the intended reliance on the exemption set forth in Section 602.1 of the TSX Company Manual, strategic initiatives, objectives, market position, industry trends, general economic conditions, expected expenditures, expected cost savings and financial results, are forward ‐ looking statements. Any statements contained in this Announcement that are not statements of historical fact are, or may be deemed to be, forward ‐ looking statements. These forward-looking statements, which may use words such as "aim", "anticipate", "believe", "could", "intend", "estimate", "expect", "may", "plan", "project" or words or terms of similar meaning or the negative thereof, are not guarantees of future performance and are subject to known and unknown risks and uncertainties. There are a number of factors including, but not limited to, commercial, operational, economic and financial factors, that could cause actual results, financial condition, performance or achievements to differ materially from those expressed or implied by these forward looking statements. Many of these risks and uncertainties relate to factors that are beyond the Company's ability to control or estimate precisely, such as changes in taxation or fiscal policy, approval from senior lenders to draw down under existing debt facilities, future market conditions, currency fluctuations, the behaviour of other market participants, the actions of governments or governmental regulators, or other risk factors, such as changes in the political, social and regulatory framework in which the Company operates or in economic or technological trends or conditions, including inflation, recession and consumer confidence, on a global, regional or national basis. Given those risks and uncertainties, readers are cautioned not to place undue reliance on forward-looking statements. Forward-looking statements speak only as of the date of this Announcement. Each of the Company, Peel Hunt and/or BMO expressly disclaims any obligation or undertaking to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise unless required to do so by applicable law or regulation. The information in this Announcement is subject to change.

Other Cautions

Peel Hunt and BMO, each which is authorised and regulated in the United Kingdom by the FCA, are acting exclusively for the Company and for no one else in connection with the Placing and will not regard any other person (whether or not a recipient of this Announcement) as a client in relation to the Fundraise or any other matter referred to in this Announcement and will not be responsible to anyone other than the Company for providing the protections afforded to their respective clients or for giving advice in relation to the Placing or any other matter referred to in this Announcement. Peel Hunt's responsibilities as the Company's nominated adviser under the AIM Rules for Nominated Advisers are owed solely to the London Stock Exchange and are not owed to the Company or to any Director or to any other person.

In connection with the Placing, Peel Hunt, BMO and any of their respective affiliates, acting as investors for their own account, may take up a portion of the shares in the Placing as a principal position and in that capacity may retain, purchase, sell, offer to sell for the own accounts or otherwise deal for their own account in such shares and other securities of the Company or related investments in connection with the Placing or otherwise. Accordingly, references to Placing Shares being offered, acquired, placed or otherwise dealt in should be read as including any issue or offer to, or acquisition, placing or dealing by, Peel Hunt, BMO and any of their respective affiliates acting in such capacity. In addition, Peel Hunt, BMO and any of their respective affiliates may enter into financing arrangements (including swaps) with investors in connection with which Peel Hunt, BMO and any of their respective affiliates may from time to time acquire, hold or dispose of shares. Neither Peel Hunt nor BMO intend to disclose the extent of any such investment or transactions otherwise than in accordance with any legal or regulatory obligations to do so.

This Announcement is being issued by and is the sole responsibility of the Company. No representation or warranty, express or implied, is or will be made as to, or in relation to, and no responsibility or liability is or will be accepted by or on behalf of Peel Hunt or BMO (apart from the responsibilities or liabilities that may be imposed by the Financial Services and Markets Act 2000, as amended ("FSMA") or the regulatory regime established thereunder) and/or by any of their respective affiliates and/or any of their respective Representatives as to, or in relation to, the accuracy, adequacy, fairness or completeness of this Announcement or any other written or oral information made available to or publicly available to any interested party or their respective advisers or any other statement made or purported to be made by or on behalf of Peel Hunt and/or BMO and/or any of their respective affiliates and/or by any of their respective Representatives in connection with the Company, the Fundraise Shares or the Fundraise and any responsibility and liability whether arising in tort, contract or otherwise therefor is expressly disclaimed. No representation or warranty, express or implied, is made by Peel Hunt or BMO, and/or any of their respective affiliates and/or any of their respective Representatives as to the accuracy, fairness, verification, completeness or sufficiency of the information or opinions contained in this Announcement or any other written or oral information made available to or publicly available to any interested party or their respective advisers, and any liability therefor is expressly disclaimed.

The information in this Announcement may not be forwarded or distributed to any other person in or into the United States, Australia, the Republic of South Africa, Japan or any other jurisdiction in which such release, publication or distribution would be unlawful and may not be reproduced in any manner whatsoever. Any forwarding, distribution, reproduction or disclosure of this Announcement, in whole or in part, is unauthorised and failure to comply with this directive may result in a violation of the Securities Act or the applicable laws of other jurisdictions.

This Announcement does not constitute a recommendation concerning any investor's options with respect to the Fundraise. Recipients of this Announcement should conduct their own investigation, evaluation and analysis of the business, data and other information described in this Announcement. This Announcement does not identify or suggest, or purport to identify or suggest, the risks (direct or indirect) that may be associated with an investment in the Fundraise Shares. The price and value of securities can go down as well as up and investors may not get back the full amount invested upon the disposal of the shares. Past performance is not a guide to future performance. The contents of this Announcement are not to be construed as legal, business, financial or tax advice. Each investor or prospective investor should consult his or her or its own legal adviser, business adviser, financial adviser or tax adviser for legal, business, financial or tax advice.

Any indication in this Announcement of the price at which the Company's shares have been bought or sold in the past cannot be relied upon as a guide to future performance. Persons needing advice should consult an independent financial adviser. No statement in this Announcement is intended to be a profit forecast or profit estimate for any period and no statement in this Announcement should be interpreted to mean that earnings, earnings per share or income, cash flow from operations or free cash flow for the Company for the current or future financial periods would necessarily match or exceed the historical published earnings, earnings per share or income, cash flow from operations or free cash flow for the Company.

The Placing Shares to be issued pursuant to the Placing and the Subscription Shares will not be admitted to trading on any stock exchange other than the AIM Market of the London Stock Exchange and the TSX. The Fundraise Shares, will, when issued in accordance with the rules of the TSX, form part of the ordinary shares of the Company currently listed for trading on the TSX.

Neither the content of the Company's website (or any other website) nor the content of any website accessible from hyperlinks on the Company's website (or any other website) is incorporated into, or forms part of, this Announcement.

This Announcement has been prepared for the purposes of complying with applicable law and regulation in the United Kingdom and the information disclosed may not be the same as that which would have been disclosed if this Announcement had been prepared in accordance with the laws and regulations of any jurisdiction outside the United Kingdom.