Mathematical Prediction of Frozen Wall Thickness in Shaft Sinking

A Stefan problem is analyzed for the case of rock freezing during shaft sinking. It is shown that the rate of thermal diffusion in rock mass is comparable with the velocity of the boundary between different phases. The Stefan problem is solved for a single shaft using the finite difference method. The procedure for generalizing the calculation data on thickness of the frozen wall in a single shaft for the case of many shafts is improved. The frozen wall thickness forming around freezing pipes is calculated in terms of shaft 1 in the mine of Petrikovsky Mining and Processing Plant of Belaruskali.