The National Stone, Sand & Gravel Association (NSSGA) has been disseminating this list of “talking points” about how aggregates mining — both surface and underground — is different from coal mines. The organization pointed out these differences as well after the Sago, Aracoma, and Utah and Indiana coal mine incidents in 2006 and 2007, respectively.
- Extracted product is non-combustible, non-flammable;
- No flammable gases such as methane are present; MSHA-approved (permissible) equipment not required in stone facilities such that regular automobiles, trucks and loaders can be used;
- Extraction methods create large open spaces for access by large equipment; large openings accommodate emergency equipment used by non-facility emergency services;
- More stable mineral formations resulting in stable mine roofs; minimized needs for additional roof supports;
- Emergency escape and access easier because of large spaces in mine;
- Most are only a few hundred feet deep; horizontal tunnel access permits large mobile equipment to easily enter facility;
- During emergency, more equipment choices available to operators because reduced hazard permits used of “un-approved” equipment;
- Minimal need for certified mine rescue teams because local fire departments, or emergency services, are able to respond;
- Due to size of large open spaces, and mining methods, mechanical mine ventilation usually not required or is minimal; natural ventilation works well.