Altamira Gold Corp. announced the results of initial column leach tests on mineralized drill core from the Maria Bonita gold discovery. Highlights: column leach metallurgical tests (simulating a heap leach) of a composite drill core sample of mineralized saprolite material from the Maria Bonita gold discovered at Cajueiro, returned an excellent gold recovery of 88% for a feed size of 100% passing 9.5mm.

The Maria Bonita bedrock or primary mineralization has a broad halo of oxidised saprolite material containing gold associated with the intrusive-hosted and disseminated bedrock mineralization. A coherent, gold-mineralized saprolite zone, defined by a 0.4g/t gold-in-soil contour, extends over an area of approximately 320m by 270m (9 hectares) To date, both diamond and auger drilling define the thickness of the saprolite as between 4 and 17m. The company intends to conduct further tests to optimise the leach dynamics and scope a potential fast track, low cost, initial operation to mine the mineralized saprolite.

A second diamond drill programme of approximately 5,000 metres is underway to test the anomalous magnetic and soil geochemistry footprint of the target. Holes MBA010 and MBA011 were completed during the month and samples are in the laboratory for analysis. Maria Bonita column leach test results.

The current column leach test results complement agitated leach test results released on March 2nd, 2023, and April 12th, 2023, using both cyanide and thiosulphate leaching agents respectively which were very positive and resulted in +90% gold recoveries. For the current test, samples of approximately 30kg were prepared from composited quarter core subsamples of the initial diamond drilling program (holes MBA001-MBA005). The samples were composited from up to forty-two individual core samples, each generally representing a one metre interval of diamond drill core.

The test work was conducted under the observation of the Company's consulting. metallurgist, Ian Gordon Hall Dun BSc (Eng), MSc. No of subsamples, Weighted avg grade g/t Au, Lab head grade g/t Au, Difference %, Saprolite, 34, 1.02, 1.18, 14%, Fresh rock, 42, 1.07, 1.07, 0%.

Estimated head grades (from weighted drill assay composites) versus average assayed head grades at the metallurgical laboratory. Samples were first crushed to 80% passing 9.5mm; Head grades analysed in the laboratory were broadly in line with the estimated grades from the calculated drill core composite assay grades. The saprolite sample received by the laboratory contained 14% more gold than the estimated grade of the core composites making up the sample.

This positive difference in the saprolite analysis might reflect the presence of physical gold within the saprolite. Further work is warranted on finer crush and grind sizes to evaluate whether a suitable liberation and recovery combination for heap leaching versus the demonstrated agitated leach route (greater than 90% gold recovery) is likely to be economically attractive for the fresh rock material. Further metallurgist and the Company intends to conduct further tests to optimize the leach dynamics and scope an potential fast track, low cost, initial operation to mine the mineralized saprolite.

Prior diamond drilling returned excellent results from the initial nine diamond drill holes which include 69m @ 1g/t gold in MBA005, 50m @ 1.1 g/t gold in MBA004, 55m @ 1.0 g/t gold in MBA002, 50m @ 1.0 g/t gold in MBA001 and 45m @ 1.4 g/t gold in MBA003. Disseminated gold mineralization in the initial discovery holes is hosted within rhyolitic intrusive rocks. Importantly, although there is no outcrop in the discovery area, the mineralization is present from surface over most of the known mineralized zone to date.

A second diamond drill programme of approximately 5,000 metres is underway to test the anomalous magnetic and soil geochemistry footprint of the target. Holes MBA010 and MBA011 were completed during the month and samples are in the laboratory for analysis. The current column leach test results complement agitated leach test results released on March 2nd, 2023, and April 12th, 2023, using both cyanide and thiosulphate leaching agents respectively which were very positive and resulted in +90% gold recoveries.

For the current test, samples of approximately 30kg were prepared from composited quarter core subsamples of the initial diamond drilling program (holes MBA001-MBA005). The samples were composited from up to forty-two individual core samples, each generally representing a one metre interval of diamond drill core. The samples were submitted to Testwork Desenvolvimento de Processo Ltda in Nova Lima, Minas Gerais, Brazil.

The test work was conducted under the observation of the Company's consulting Samples were first crushed to 80% passing 9.5mm. Head grades analysed in the laboratory were broadly in line with the estimated grades from the calculated drill core composite assay grades (Table 1). The saprolite sample received by the laboratory contained 14% more gold than the estimated grade of the core composites making up the sample.

This positive difference in the saprolite analysis might reflect the presence of physical gold within the saprolite. To date, visible gold has not been observed in the drill core however rare, fine physical gold has been observed from the panning of soils. This might represent upside for future bulk sampling of saprolite.

Each leach sample was agglomerated and conditioned using 2kg/t of cement and lime to facilitate both a pH of 10.5-11 and percolation through the column over the life of the leach test. Laboratory columns of 1m height and 6 inches diameter were used. The percolation rate was 10 litres per hour per square metre of surface area.

Cyanide concentrations of 300-500ppm were used. The columns were irrigated for 30-45 days. The results show a net gold recovery of 88.2% with a cyanide consumption of 750g/t for saprolite (Table 2).

This is a very positive result for a coarse 9.5mm crush top-size, implying that the weathered saprolite is amenable to heap leaching and offering potential to further investigate crushing, agglomeration, and reagent dosing to further optimise the results. Further metallurgical testing to investigate crushing and grinding metrics, sample conditioning and reagent consumption is planned using drill core from the recently started second drill programme. In addition, shallow auger and diamond drilling will be used to supplement the drill database for the surficial saprolite gold deposit, leading to a mineral resource estimate.