Susceptibility of coal to spontaneous combustion verified by modified adiabatic method under conditions of Ostrava–Karvina Coalfield, Czech Republic

• We checked modified adiabatic method for self heating test of coal.
• The novel aspects of the research - the modified adiabatic method was used first time in the Czech Republic.
• The initial temperature of the method was increased to 120 °C.
• The time of the test was adjusted to 60 minutes – parameter t60.
• We tested 36 coal samples of Ostrava-Karvina Coalfield, Czech Republic.

The susceptibility of coal to spontaneous combustion is a physical–chemical property of coal that can be determined by a laboratory test. A number of laboratory methods verifying the coal susceptibility to spontaneous combustion exist, e.g. the oxidation method under adiabatic conditions, method according to the author Olpinski, method of pulse calorimetry, and CPT (Crossing Point Temperature) method. Any versatile method has not been so far developed, which would become a generally respected and utilized laboratory procedure of objective assessment. The paper deals with the verification of the widely used adiabatic oxidation method. The modification of the method in question consists in the adjustment of the test process by increasing the initial temperature. This procedure enables shortening the test process. Shortening the laboratory test duration creates conditions for wider utilization of the method in practice. The paper presents results of 36 tests of Ostrava–Karvina Coalfield coal samples which confirmed an applicability of the modified adiabatic method in practice.