Regulus provides update on metallurgical test program with Nuton

Regulus Resources provided an update on the Phase Two metallurgical test program with Nuton, a Rio Tinto (RIO) venture. As well, the Company provided an update on the integrated resource estimate currently being completed with Compania Minera Coimolache, to evaluate the integrated Coimolache Sulphide/AntaKori copper-gold project. The Company continues to work with Nuton to evaluate Nuton’s proprietary sulphide bio-leaching technologies at the AntaKori project. The Phase One program identified that material from AntaKori was amenable to Nuton’s proprietary sulphide bio-leaching technology. In the Phase Two program, a variety of conditions are being evaluated, with each test column using different sets of conditions to evaluate the optimal setup for leaching AntaKori mineralization. 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 Two program are very encouraging, as Nuton was able to achieve attractive copper extractions utilizing its Nuton bio-leaching technology on both styles of mineralization. As well, this test work 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%. To date, the highest copper extraction for porphyry-hosted chalcopyrite mineralization is 87.9%. As mentioned previously, this phase of test work is designed to evaluate various conditions to establish the optimum additives for bio-leaching 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% extraction. However, copper extractions in both of these columns continue to trend upwards. 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 bio-leaching technology. The Company will report on these additional columns when they are at or nearing completion. 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 towards 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 mid-year. 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.