subaquatic coal oxidation; water dissolved oxygen; kinetics, weathering

Subaquatic oxidation of two bituminous coals by water-dissolved oxygen was investigated using batch reactor equipped with membrane oxygen sensor. Effects of time, temperature and coal grain size were studied as basic parameters influencing the oxidation process. Obtained results showed the subaquatic coal oxidation can be considered as interaction of the first reaction order with respect to oxygen. From temperature dependence of oxidation rate, activation energies E = 72 + 4 kJ.mol-1 and/or 50 + 4 kJ.mol-1 were calculated. For the samples, oxygen consumption RO2 was found to be in the range of 2 ?10-7 mol O2.kg-1.s-1 to 6 ?10-7 mol O2.kg-1.s-1, such values being quite comparable with RO2 for aerial oxidation of bituminous coals.

Subaquatic oxidation of two bituminous coals by water-dissolved oxygen was investigated using batch reactor equipped with membrane oxygen sensor. Effects of time, temperature and coal grain size were studied as basic parameters influencing the oxidation process. Obtained results showed the subaquatic coal oxidation can be considered as interaction of the first reaction order with respect to oxygen. From temperature dependence of oxidation rate, activation energies E = 72 + 4 kJ.mol-1 and/or 50 + 4 kJ.mol-1 were calculated. For the samples, oxygen consumption RO2 was found to be in the range of 2 ?10-7 mol O2.kg-1.s-1 to 6 ?10-7 mol O2.kg-1.s-1, such values being quite comparable with RO2 for aerial oxidation of bituminous coals.