Determination of the ash content of coal without ashing: A simple technique using laser-induced breakdown spectroscopy

The bituminous coal samples were analyzed using the technique of laser-induced breakdown spectroscopy (LIBS). The fraction of the ash content of the coal was spectroscopically determined by a technique requiring only two measurements of the LIBS spectrum of the coal, and the results were compared to the ash fraction determined by actual ashing of the coal in a furnace. An excellent correlation (r = 0.99) was obtained between the spectroscopically determined ash fraction and the fraction of ash content determined by actual ashing of the coal. This excellent coefficient of correlation provides sufficient confidence in the measurement of the ash content by this simple and quick method using the LIBS technique.