The Limiting Content of Combustibles to Prevent Minestone from the Spreading of Fire

Abstract

The limiting content of combustibles to spread/suppress the fire in the minestone of the coal tailing dump (gangue) was studied. This knowledge appears crucial mainly when deciding on the possible usage of minestone as fireproof material for engineering purposes. Theoretical analysis, laboratory experiments as well as scale (in situ) considerations were performed. In the laboratory, a model series of coal–mineral matter mixtures and six representative minestone samples of coal tailing dump (gangue) were investigated. The thermoanalytical (TG/DSC) method was used to evaluate the content of combustibles with their energetic equivalent, EEC (%). The EEC has been suggested as a proper way to quantify the content of combustibles in the samples. Based on the original combustion calorimetric test, an EEC value of 7–9% was found to be a limit between fireproof and fire spreading minestone in a laboratory, while only 2% of combustibles resulted as the limit from the theoretical analysis. On the other hand, respecting real conditions of thermally active dump (Heřmanice tailing coal dump), the laboratory limit of 7–9% of EEC was then assessed to shift to the value of about 10 ± 1% for practice.

Keywords

• coal waste dump
• combustible matter
• underground fire
• calorimetry