UNBIASED METHODS FOR THE MORPHOLOGICAL DESCRIPTION OF CHAR STRUCTURES

This paper shows how the most relevant morphological parameters of cha rs can be accurately measured with the aid of standard image analysis techniques. The descriptions of char particles thus obtained allow a m ore precise application of most of the classification schemes in use t o date, or the production of useful data for the modelling of p.f. com bustion. The application of these techniques is illustrated with a sim plified scheme for the classification of char structures, with emphasi s on the discrimination of the main structural types considered in cur rent classification systems. Data obtained from the application of the proposed techniques to char samples from three coals of different ran k and maceral composition clearly reflect the differences that could b e expected from the plastic properties of the parent coals. The accura cy and objectivity of the measurements by these techniques make them a valuable tool for improving the repeatability and reproducibility of char petrographic analyses. (C) 1997 Elsevier Science Ltd.