| AVS 57th International Symposium & Exhibition | |
| Applied Surface Science | Tuesday Sessions |
| Session AS-TuA |
| Session: | Advances in Surface and Interface Imaging |
| Presenter: | B.P. Yatzor, University at Buffalo |
| Authors: | B.P. Yatzor, University at Buffalo H.D. Liang, China University of Mining and Technology, China J.A. Gardella Jr., University at Buffalo |
| Correspondent: | Click to Email |
A significant problem in the combustion of coal is the release of toxic elements into the atmosphere in gaseous and solid (particulate) forms. In China, villagers use coal, exposed at the surface by erosion, to heat their homes and cook their meals. It is believed that coal combustion is a potential source of endemic diseases [1, 2].
Coal samples were collected from the province of Guizhou in China. In this study, an ION-TOF V equipped with a bismuth primary ion source was used to analyze coal directly without any chemical treatment. Mechanical polishing was performed to create a flat surface for analysis. Analyses revealed that there are distinctions between the organic and inorganic phases of coal. Fluorine was been determined to come from an inorganic phase rather than an organic phase. Two different forms of elemental sulfur were determined through ion imaging. The first one was determined to be organic in nature, while, the second derives from pyrite (FeS2).
The high spatial resolution of TOF-SIMS can be used to distinguish between different domains in coal, revealing the relationship between specific components suspected of involvement in toxicity of particulate emissions and the coal components.
STXM images, from powder samples suspended on Si3N4 windows, show complementary chemical images of carboxylic, aromatic and carbonate species from the C1s edge. Studies were performed using the third generation Canadian Light Source synchrotron facility located in Saskatoon, Saskatchewan. The soft microscopy beamline (10ID-1) was used for analyses.Spectral shifts in STXM NEXAFS spectra allow carbonate species to be distinguished from carboxylic species. With the help of reference materials, aromatic species could be distinguished from aliphatic species. However, using TOF-SIMS for distinguishing such species would prove to be very difficult, which is why STXM is a good complementary technique for coal studies.
[1] Finkelman et al. (2004) Int. J Coal Geol. 59, 19–24.
[2] Finkelman et al. (2002) Int. J Coal Geol. 50, 425– 443.