"As mining goes deeper, rock becomes hotter. The mining process itself exposes large surface areas that release geothermic heat from the rock into a mine's ventilation system. Operating mining equipment also releases quantities of heat. Ores at many mines contain minerals, primarily sulfides that exhibit exothermic behavior when exposed to air. Past mining practice has been to use underground refrigeration units to cool mine air. However, energy costs limit mechanical refrigeration. A solution that could lower energy costs is to insulate mine drifts. U.S. Bureau of Mines (USBM) researchers are developing an "insulating" material for this need." - NIOSHTIC-2 NIOSHTIC no. 20024035

National Institute for Occupational Safety and Health