APPLICATION OF MACERAL ANALYSIS TO CARBONIZATION

In the late 1950s American steel companies had a serious problem with the quality of their metallurgical coke. The larger blast furnaces they were building required stronger coke and their supply of good coking coals was diminishing. Professor William Spackman solved the problem by studying the actual properties of the different coal macerals using a variety of techniques including reflected light microscopy and the microscope hot stage. He found that he needed to go back to the original definition of macerals by Marie Stopes in which their distinct chemical and physical properties are referenced. He actually measured some of these maceral properties. He concluded that a maceral and reflectance analysis characterized a coal sample so well that the behavior of a coal and coal mixes could be predicted. This work allowed various steel companies to develop accurate techniques for predicting coke properties. His emphasis on macerals has led to much past and current research on maceral behavior using such diverse techniques as photoacoustic microscopy, fluorescence microscopy, FTIR, TGA, stable isotope analysis, surface area and porosity analysis. Density gradient centrifugation has allowed the production of very clean single maceral concentrates to characterize. More recent work has extended the range of products so studied to petroleum coke, kerogen, graphites, carbon-carbon composites, and aircraft and automobile brakes.