The paper refers to model characteristics that describe the process of coal self-heating in the context of standardized parameters of the ignition temperature and the Graham’s coeffi cient. Based on investigation of coal samples taken from selected coal seams, different in parameters, this study outlines graphics that correspond to non-standard values of mutual correlations between temperatures and Graham’s coeffi - cients that are typical for the samples.

 

The stress was put on importance of such differences for correct evaluation of hazards and the research made it possible to define a correcting factor enabling mapping the results of laboratory examination of coal oxidation onto real oxidation in coal seams. Additionally, the coefficient that reflects vulnerability of coal to self-ignition was developed with account to inconsistency of the coal oxidation process. Finally, a new method for assessment of hazard level is suggested, i.e. the method that takes advantage of the index of possible self-heating of coal that is a merge of coal seam breakdown by groups of self-ignition tendency that is currently in use and the index of coal vulnerability to self-ignition. Verification of the new evaluation method is carried out with use of fires that had occurred in examined coal seams.