Influence of oxidation in aqueous medium on the structure and properties of lignites

In this paper, the effect of oxygen uptake on the structure and properties of lignites was investigated using five different Turkish lignites. Lignite samples were oxidised in aqueous medium at 423 K under 1.5 MPa partial pre ssure of oxygen for 60 min. Relations between the oxygen uptake and the ele mental compositions of the lignite samples were investigated. FT-i.r. techn ique was applied to the original and oxidised lignite samples to investigat e functional group analyses. Mercury porosimetry analyses of the samples we re carried out up to about 220 MPa. Effect of oxygen uptake on the bulk den sity, apparent density, porosity, and pore radius of the lignite samples we n compared. Differential Thermogravimetry (DTG) technique was performed to compare the thermal reactivity of the original and oxidised lignite samples . (C) 2000 Elsevier Science Ltd. All rights reserved.