Hecla Mining Company's underhand closed bench technique has helped make safer mining shafts with fewer seismic issues and sped up mining as a result. The technique uses cemented mill tailings for backfilling areas that have been dug out. This makes the mining process in the following cuts less dangerous because the miners are always working beneath a reinforced cemented-backfill if the stress to the mine causes a rock burst or violent failure of rock.

January 30, 2024