GR Silver Mining Reports Silver Concentrate Grade After Processing Underground Bulk Sample

VANCOUVER – GR Silver Mining Ltd. reported positive preliminary metallurgical test work results after processing a 2,700 tonne bulk sample excavated from the San Juan Area underground development - San Juan Vein & Breccia at the Plomosas Silver Project, Sinaloa, Mexico. The Bulk Sample was sent for off-site processing, generating 27 tonnes of high-grade silver-gold concentrate. The Bulk Sample was excavated from a zone representative of the Ag-Au-Pb-Zn hydrothermal breccia in the upper levels of the underground development, to initiate preliminary metallurgical test work on the San Juan Area. The historical San Juan underground development has no history of previous production and is currently being drilled by the Company.

The 2,700 t Bulk Sample was transported off site to a third party owned 262 tpd processing plant to conduct the metallurgical test work. The plant is located 3 km from mine site and consists of a crusher, grinding to P80% - 74 microns, and two stages of flotation cleaning. Standard flotation reagents were applied. The bulk sampling test work was completed free from the use of lime or cyanide.

President and CEO, Marcio Fonseca, said, “We are very encouraged with the results of the initial bulk sampling of the San Juan Breccia, which has indicated that a high- grade silver-gold concentrate can be produced using standard grind and flotation processing technology. Our current focus continues to advance surface and underground drilling with five diamond core rigs at the Plomosas Silver Project. We are also carrying out preliminary metallurgical studies to investigate potential metallurgical flow sheets, aiming to achieve high-value final concentrate products from the areas being drilled.”