Coal Spontaneous heating; Evaluation;

Two principal methods to quantify the spontaneous combustion (?spon-com?) risk of coal in underground longwalls are described and compared: 1) zonal method, and 2) phase method. Using the zonal method, particular zones (localities) of longwall site are evaluated, i.e. i) starting entry; ii) intake main gate; iii) return gate; iv) longwall face area. The resultant ?spon-com? risk within a given longwall working site is given then by summing partial ?spon-com?risks in all given zones. This approach is known as ?M- criterion? and it is incorporated in the existing legislation actually valid in Czech Republic.

Two principal methods to quantify the spontaneous combustion (?spon-com?) risk of coal in underground longwalls are described and compared: 1) zonal method, and 2) phase method. Using the zonal method, particular zones (localities) of longwall site are evaluated, i.e. i) starting entry; ii) intake main gate; iii) return gate; iv) longwall face area. The resultant ?spon-com? risk within a given longwall working site is given then by summing partial ?spon-com?risks in all given zones. This approach is known as ?M- criterion? and it is incorporated in the existing legislation actually valid in Czech Republic.