POX Results Are Another Milestone For Advancement Of Hycroft Mine

WINNEMUCCA, NV – Diane R. Garrett, President and Chief Executive Officer of Hycroft Mining Holding Corporation, said, “The updated MRE reflects approximately 55% growth in both gold and silver Measured and Indicated Mineral Resources, and increases in Inferred Mineral Resources of 50% for gold and 38% for silver representing an impressive resource growth. Importantly, following only approximately 14 months of drilling since the discovery of two new high-grade silver systems, a high-grade mineral resource with underground potential has been established demonstrating the continuity of both the Brimstone and Vortex high-grade systems which remain open along strike and at depth.”
The growth in overall mineral resources and the establishment of the high-grade mineral resource with underground potential reflect a combination of improved metallurgical performance, results from 70 drill holes, geologic modeling based on new interpretations, and commodity price assumptions. The MRE is based on a flowsheet utilizing milling and pressure oxidation (“POX”) for sulfide and certain transition mineralization and heap leaching process for oxide and other transition mineralization.
The Company is also extremely pleased with the results of the metallurgical test work for POX demonstrating higher gold recoveries and confirming silver recoveries. The robust POX metallurgical results represent another significant milestone in the advancement of the Hycroft Mine and a critically important step in defining the project as it moves into the next phase toward commercial operation.
The Company is continuing to evaluate a roasting process alternative, which could potentially provide a third revenue stream through the by-product production and sale of sulfuric acid needed in the lithium, copper, and fertilizer industries. Producing and selling sulfuric acid could essentially convert a significant neutralization cost in the POX process into a by-product revenue from the roasting process. Initial desktop analysis indicates operating costs and capital costs could be comparable to a POX process. The Company’s ongoing roasting test work is focused on optimizing operating parameters, including temperature and retention times, in addition to project design and equipment selection.