Mr. John Black reports

REGULUS REPORTS ATTRACTIVE COPPER EXTRACTION RATES USING NUTON BIO-LEACHING AND PROVIDES UPDATE ON INTEGRATED SULPHIDE PROJECT RESOURCE ESTIMATE

Regulus Resources Inc. has provided an update on the phase 2 metallurgical test program with Nuton LLC, a Rio Tinto venture. As well, the company has provided an update on the integrated resource estimate currently being completed with Compania Minera Coimolache SA to evaluate the integrated Coimolache sulphide/AntaKori copper-gold project.

Nuton phase 2 program

The company continues to work with Nuton to evaluate Nuton's proprietary sulphide bioleaching technologies at the AntaKori project. The phase 1 program identified that material from AntaKori was amenable to Nuton's proprietary sulphide bioleaching technology (see July 6, 2023, press release). In the phase 2 program, a variety of conditions are being evaluated, with each test column using different sets of conditions to evaluate the optimal set-up for leaching AntaKori mineralization (particularly enargite-rich high-sulphidation mineralization, which makes up the bulk of mineralization at the AntaKori project).

The company is reporting on the progress of four columns today. Three of the four columns were focused on testing different conditions for enargite-rich high-sulphidation mineralization, while the other column was utilized to test chalcopyrite-dominant porphyry mineralization. The results thus far from the phase 2 program are very encouraging as Nuton was able to achieve attractive copper extractions utilizing its Nuton bioleaching technology on both styles of mineralization. As well, this testwork has refined the understanding of which set of conditions produces attractive copper extractions for enargite-rich high-sulphidation mineralization. To date, the highest copper extraction for enargite-rich high-sulphidation mineralization is 88.3 per cent. To date, the highest copper extraction for porphyry-hosted chalcopyrite mineralization is 87.9 per cent. As mentioned previously, this phase of testwork is designed to evaluate various conditions to establish the optimum additives for bioleaching enargite-rich high-sulphidation mineralization. As such, two of the columns identified conditions that produced slower extraction rates and hence less favourable conditions than the column conditions that produced the 88.3-per-cent extraction. However, copper extractions in both of these columns continue to trend upward. Four additional columns have since been started to further refine the optimal conditions achieved and reported here for leaching AntaKori's enargite-rich high-sulphidation mineralization with Nuton's bioleaching technology. The company will report on these additional columns when they are at or nearing completion.

Integrated sulphide project

Regulus and Coimolache, owner of the Tantahuatay oxide gold mine adjacent to the AntaKori project, continue to advance the integrated sulphide project resource estimate. The parties have worked collaboratively over the past several months to develop an integrated geological model effectively blending views on geology, structure and mineralization styles, which was a critical step before moving toward an integrated resource estimate. The parties have hired SRK Peru to develop the resource estimate on the integrated sulphide project, and it is anticipated that the study will be completed midyear. As per the agreement between the parties, the results of this study can only be publicly reported or shared with third parties upon mutual agreement of the parties.

John Black, chief executive officer of Regulus, commented: "We are very encouraged by the results of the phase 2 program with Nuton. Conditions have been established under which attractive copper extraction is achieved from both high-sulphidation and porphyry mineralization utilizing Nuton's bioleaching technology. With several other columns under way, we continue to view Nuton's bioleaching technology as one of several potential processing options for mineralization at AntaKori. As well, we have made considerable progress on the integrated resource estimate with Coimolache, with the creation of an integrated geological model. SRK Peru now has all the information they need to complete the resource estimate on the integrated sulphide project, and we look forward to receiving the final results soon."

Qualified person

The scientific and technical data contained in this news release pertaining to the AntaKori project have been reviewed and approved by Dr. Kevin B. Heather, chief geological officer, FAusIMM, who serves as the qualified person under the definition of National Instrument 43-101.

About Regulus Resources Inc.

Regulus is an international mineral exploration company run by an experienced technical and management team. The principal project held by Regulus is the AntaKori copper-gold-silver project in northern Peru. The AntaKori project currently hosts a resource with indicated mineral resources of 250 million tonnes with a grade of 0.48 per cent copper, 0.29 gram per tonne gold and 7.5 g/t silver and inferred mineral resources of 267 million tonnes with a grade of 0.41 per cent copper, 0.26 g/t Au and 7.8 g/t Ag (independent technical report prepared by AMEC Foster Wheeler (Peru) SA, a Wood company, titled "AntaKori Project, Cajamarca Province, Peru, NI 43-101 Technical Report," dated Feb. 22, 2019 -- see news release dated March 1, 2019). Mineralization remains open in most directions.

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