In the first part of this study density-separated, coal fractions of Point of Ayr coal were analysed using petrographic techniques and infrared (IR) spectroscopy. Density separations were carried out on the -38 + 20 mu m size fraction using sodium polytungstate as the dense liquid medium. Petrographic analysis and FTIR analysis, using the diffuse reflectance technique, were carried out on the density-separated fractions. For the FTIR analysis the samples were micronized to give a particle size of 2 mu m which leads to a considerable improvement in the quality of the recorded spectra without the need for dilution with potassium bromide. Area measurements of the aromatic (A(Ar)) and aliphatic (A(Al)) CH stretch absorptions together with area ratios of these absorptions (A(Ar)/A(Al)) were determined for each of the density fractions and the feed coal. The A(Ar)/A(Al) ratios showed an increase with higher density, indicating a change in aromaticity as the density of the fractions is increased. A linear correlation between the area ratios and major maceral analysis was found. The results of this part of the study thus showed that changes in the IR spectrum could be directly related to the maceral composition, and that the diffuse reflectance technique could be used to obtain consistent good quality IR spectra of powdered coals. Using the same FTIR technique the A(Ar)/A(Al) ratios of 29 world coals was found and correlated with maceral analyses of the coal, maceral analysis plus rank and the grey-scale histogram produced during automated, petrographic analysis of the coals using image analysis. A poor correlation was obtained between maceral analysis and the A(Ar)/A(Al) ratio. The correlation improved markedly when rank was included, but the best correlation (R-2 = 0.96) was Obtained against the grey-scale histogram. This work indicates that it may be possible to use the diffuse-reflectance FTIR technique as a rapid characterization technique for coal reactivity.