Paramagnetic centres in exinite, vitrinite and inertinite

Exinite, vitrinite and inertinite from durain, vitrain and clarain of Polis h medium-rank coal with 85.6% C were investigated by X-band (9.3 GHz) elect ron paramagnetic resonance spectroscopy. Multicomponent structure of the EP R spectra of these macerals was analysed. The number of component lines, th eir lineshapes and parameters: linewidths and g factors, were determined. T otal concentrations and concentrations of paramagnetic centres responsible for the component lines were measured. The broad Gaussian, broad Lorentzian and narrow Lorentzian lines were observed in the experimental spectra of e xinite and vitrinite. The EPR spectra of inertinite are superposition of tw o narrow Lorentzian lines with different linewidths. The evolution of param agnetic centres during heating of the macerals at 300-650 degrees C was stu died. Paramagnetic centres with broad Lorentzian lines are the most active ones in the thermal decomposition. The EPR results indicate reactions betwe en individual macerals during thermal decomposition of coal. Thermally exci ted multiplet states were found in exinite and vitrinite.