CHEMICAL CHARACTERIZATION OF SUB-BITUMINOUS COAL FROM THE ARAUCO PROVINCE – CHILE
The chemical and sorptive characteristics of mineral coals extracted from a mine in Lebu (Biobío Region, Chile) and its derivatives were studied. These derivatives were obtained by applying a thermal treatment in an environment with N2 and CO2 at different experimental conditions, in order to increase their specific surface. In addition, coals were characterized by using proximal analysis, elementary analysis and petrographic analysis. In order to know their structure and surface, Boehm titration analysis, FTIR infrared spectroscopy, X-ray diffraction and scanning electron microscopy were performed. The surface of the selected carbons was modified by selectively oxidizing it with (NH4)2S4O8 and with H2O2 e impregnating with an iron solution for the study with H2O2 In the oxidation of H2O2, the work was carried out at different pH. The results show a moderate homogeneity between different types of seams studied, whereas when coals are treated with heat or strong oxidants, increases its surface and can be used with analytical applications (v.g. electroanalytical sensors).