The CIM Vancouver Branch is pleased to invite you to our March Luncheon

Keynote Speaker:  Wes Johnson, Chief Engineer

Title: Underhand Closed Bench (UCB) Mining Method at the Lucky Friday Mine

Date: March 16, 2023

Location: Pinnacle Hotel Vancouver Harbourfront

Reception Start Time: 11:30am

Lunch Start Time: 12:00pm

Presentation Start Time: ~12:30pm

Bio:

Wes Johnson is recently promoted to Chief Engineer at Hecla Mining’s corporate office.  Previously Wes was the Manager - Technical Services at the Lucky Friday Mine, Mullan, Idaho and he has worked for Hecla Mining Company for past 10 years.  While working at Lucky Friday, Wes was part of the team developing the Underhand Closed Bench mining method to control seismic energy release

Abstract:

Hecla’s Lucky Friday silver operation in Mullan, Idaho, currently stoping at approximately 2300m below ground surface, is one of the deepest mines in the western hemisphere.  Until 2020, the mine was using an underhand cut and fill method to extract near-vertical, narrow silver-lead-zinc veins.  Due to the heavily-faulted nature of the rock mass and great depth, mining-induced fault-slip seismicity posed a significant safety and production risk.  Hecla has developed a new narrow-vein underhand longhole mining method termed “Underhand Closed Bench” or UCB mining.  The intent of this method is to pro-actively trigger slip and seismicity on faults within close proximity to the stopes using large, down-dip longhole blasts.  This paper describes the development of this method which, after 2 years of execution, represents nearly 90% of the mine production.  The method has been very successful, not only inducing virtually all seismic events with the blast, but also significantly reducing the overall seismic energy release and the elimination, thus far, of damaging events.  Also, the production at the mine is up significantly, with tonnage increasing over 40% since full implementation.

Note: If you have any questions or concern about this event please don’t hesitate to contact me at neda.mining@yahoo.com