Effect of coal weathering on some geochemical parameters

The effect of coal weathering on some geochemical parameters was studied. Seven pairs of fresh and altered samples were selected from different Venezuelan coal deposits. The following analyses were performed: water and ash percent, heating value, bitumen content and composition, infrared spectroscopy, n-alkane distribution and humic substances concentration (HS). As weathering proceeds, there is a corresponding change in HS concentration. Most geochemical parameters show small changes with HS concentrations below 15%. For intense weathering, all parameters measured show important modifications. Such changes are due to the breaking of the coalʹs macrostructure.