Underground mining operations within the Pilar Mine have been active for approximately 34 years. The mine currently produces an average of 5,600 t/day and approximately 1,400 meters per month of development is expected starting in 2023 (average of 16k m/year) for the next 5 years.
The Pilar UG Mine is divided into eight main zones from a mine planning perspective: Deepening Project (or locally referred to as the Deepening Below L-965), Deepening Above L-965, Baraúna, MSBSouth, P1P2NE/R22UG, P1P2W, MSBW and, for 2022 mine planning, Project Honeypot & the Upper Areas.
The Pilar UG Mine has previously employed the following mining methods: Sublevel Stoping, VRM and Vertical Crater Retreat (“VCR”). VRM is the method currently employed, whereby ore is removed from the stope after it is blasted, and cemented paste backfill is pumped into the mined stope void to ensure geotechnical stability prior to advancing to adjacent stopes.
The mining method selection is heavily influenced by the deposit type and rock mass characteristics. Other factors influencing the selection process are the proximity of the resource to surface, the nature of the surface topography, the strength of the deposit and host rock, the configuration (i.e., shape, dimensions, and dip) of the deposit, the resource being mined, the required selectivity, productivity and overarching safety considerations.
To determine a safe and economically viable means of mining, several ........