Thermal transformation of the molecular and supramolecular structure of kerite in the interval of temperature 300—700 °C
Golybev E.A., Martirosyan O. V., Isaenko S. L., Shevchuk S. S.
Zapiski RMO (Proceedings of the Russian Mineralogical Society). 2016. V. 145. N 3. P. 105-120
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Language: Russian
Abstract
The paper displays data on studied structural and chemical transformations of solid bitumen while the heating in oxidizing atmosphere at the temperature in range from 300 to 700 °C. The studied object was the natural bitumen (higher kerite) from an occurrence at the Graham Bell island of Franz-Josef land archipelago. Transformations were investigated with use of a complex of methods: infrared and Raman spectroscopy, scanning electron microscope, atomic force microscopy, X-ray spectral microanalysis. Obtained data indicate the decrease in size of particles in the supramolecular structure during heating. Structural transformations are developing towards graphitization, but there was not observed an ordering of atomic structure comparable with the highly transformed bitumen (intermediate and higher anthraxolites, shungites). At the same time, after heating at temperature 500 °C during 30 minutes and 400 °C during 60 minutes the sample become electrically conductive. It is considered as a result of decomposition and volatilization of hydrocarbon components present in the initial material as hetero- and aliphatic groups.
Key words: natural bitumen, thermal transformations, IR spectroscopy, Raman spectroscopy, AFM microscopy.
