The Aurizona Gold Project is located in Maranhão State in northern Brazil. Aurizona is an orogenic gold deposit hosted in a greenstone belt of the São Luis Craton. There are many mineralized bodies on the property but work to date has focused on the Piaba and Tatajuba deposits on which the current resource is based.
The Aurizona mine was an active open-pit operation from 2010 to 2015, producing approximately 329 kozs of gold at an average grade of 1.3 g/t. Ore was processed through a gravity and carbon-in-leach plant with gold recoveries averaging 88%.
A Feasibility Study was released in August 2017 and outlined a mine restart plan involving an upgrade to the mill that provides for an 8,000 tpd crushing and grinding circuit that can treat all ore types. The average annual production is expected to be 136,000 ounces of gold over an initial 6.5 year mine life.
An updated Mineral Reserve Estimate reported 958,000 ounces of Proven and Probable Reserves as of December 2019 contained in 19.8 Mt of 1.5 g/t gold material (0.6 g/t gold cut-off for Piaba and Piaba East and 0.41 g/t gold cut-off for Boa Esperança). Exploration programs are ongoing and focused on expanding the resource at Tatajuba and along the Piaba trend as well as upgrading inferred resources to indicated in the Piaba underground area.
Equinox Gold released positive drill results from the 2020 Piaba underground drill program, with 96% of holes intersecting significant gold mineralization.
Equinox Gold expanded its planned 17,000 metre underground drill program at Piaba to 25,000 metres with 23,093 meters completed at press time. The objective of the drill program is to convert underground Inferred Resources to Indicated Resources in support of a Pre-Feasibility Study for potential underground development.
The Aurizona Measured and Indicated Resources (exclusive of reserves) increased 22% to 844,000 ounces of contained gold from 16.0 Mt at 1.6 g/t gold, with Measured Resources of 2.7 Mt grading 1.25 g/t gold and Indicated Resources of 13.2 Mt grading 1.7 g/t gold (based on a underground cut-off grade of 1.0 g/t Au and an open pit cut-off grade of 0.6 g/t Au).