DETERMINATION OF COAL MACERAL COMPOSITION BY MEANS OF COLOR IMAGE-ANALYSIS

With the development of Colour Image Analysis Systems (CIAS) which are capable of processing multi-colour images it has become possible to define more complex optical units in comparison to black and white image analysis systems. The colour composition of each maceral group can be defined by intensity levels of three different colours, i.e. red, green, blue, thus allowing the user to characterise macerals within small diagnostic thresholds. This investigation presents the results of the application of CIAS (Cue 3, Olympus) to coal petrology. Maceral group analyses have been carried out on a series of 7 high to medium volatile bituminous coals from the Carboniferous Coal Measures of The Netherlands, using both conventional point count analysis (PCA) and CIAS. The results show that CIAS is applicable to maceral group analysis of coals of different ranks. CIAS is time efficient as compared to PCA.