A mathematical model of heat transfer in partially insulated airways in deep, frozen ground placer mines

Large seasonal variations in the temperature of the ventilating air in mines in the arctic cause changes in the original thermal field through heat and mass exchanges between the air and the surrounding medium. These thermal interactions have major influence on climatic quality as well as on the stability of the mine openings. Thawing of walls and roof in mine airways can be reduced by various types of thermal-insulation. Application of thermal-insulation prevents deep thawing of the rockmass surrounding an airway. In this case, the mechanism of heat transfer around a frozen, underground airway would be much different. A model of heat transfer in a deep, partially insulated airway has been developed and analyzed using finite element methods. Results of the analysis show that without any thermal control, there will be stable change in temperature around the mine airway. With different insulations on the walls of the airway, roof thawing can be reduced and in certain cases, completely eliminated.