Phase 4 Metallurgical Testing Confirms Recovery Assumptions

VANCOUVER - Marimaca Copper Corp. reported the results of the phase 4 metallurgical testing program for the Company’s flagship Marimaca Copper Project , located in northern Chile.

The results confirm the recovery assumptions made in the recently released PEA which projected Marimaca to have industry leading pre-production capital costs and bottom quartile all in sustaining cash costs, delivering compelling economics.

Highlights: Comprehensive metallurgical testing program completed comprising composite samples from all defined mineral sub-zones at Marimaca, Builds upon results from Phases 1,2 and 3 testing and broadened sampling across the deposit, and provides a comprehensive assessment of variability across the deposit; Testing covered multiple items including mini-columns and 1.5m columns to give strong indication of eventual heap leach recoveries; Results confirm the recovery assumptions made in the PEA, Average life of mine recovery estimated to be 75.7% of total copper for heap leach and 40% for dump leach; Recoveries exceeded acid soluble component of total copper in virtually all samples, some by significant margins, indicating a larger proportion of the copper is acid soluble and will be recovered in heap leaching; Seawater confirmed to be compatible with heap leaching process with no reduction in recovery and some increases in recovery noted in certain mineral sub-zones; Multiple areas identified for optimization work to further improve economics of Marimaca; & Phase 5 program planned to address final metallurgical aspects ahead of a Preliminary Feasibility Study and optimize operating parameters for the Project.

Luis Tondo, CEO, said, “We are extremely pleased with the results of the Phase 4 metallurgical program, which confirm the important assumptions we have made in the PEA with respect to copper recovery at Marimaca. As in the first three phases, recoveries exceeded acid solubility ratios for virtually all samples. It was a particularly positive surprise that, in several cases, the recoveries exceeded the calculated maximum expected recovery (leaching potential) of the sample material. This is attributed to the presence of black copper oxide species, which have strong leaching profiles but did not report to the soluble copper assays. This provides us with a high level of confidence in our ability to achieve the recovery assumptions applied in the PEA. This is a significant de-risking milestone as we continue to move Marimaca towards future development and we are now planning for the next phase of studies, which we hope to commence before the end of 2020. In addition, we are continuing with our extensive exploration program to test the exciting potential in the Marimaca district.”