Mining Seminar 3rd October

Hecla's Lucky Friday mine in Mullan, Idaho, operating 2,300 meters below ground, is one of the deepest in the western hemisphere. Previously using an underhand cut-and-fill method for silver-lead-zinc extraction, the mine faced safety risks from mining-induced fault-slip seismicity. In response, Hecla introduced the Underhand Closed Bench (UCB) mining method, designed to trigger controlled seismic events through large, down-dip longhole blasts. This approach has successfully induced nearly all seismic activity during blasts, reducing overall seismic energy and eliminating damaging events. Additionally, production has increased by over 40% since implementing UCB mining.