Mossbauer spectroscopy for pyrite analysis in coal

The Mössbauer spectroscopic technique has been adapted to provide a reliable measurement of pyritic sulphur in coal. The Mössbauer method is quick, nondestructive, and adaptable to automation. It can be applied hindering the use of Mössbauer spectroscopy for pyritic measurements have been resolved. Sample homogenization techniques consistent with the spectroscopic requirements were developed. A sample holder compatible with a 5 to 10 g coal sample was designed. Two calibration curves were evaluated: one based on a mixture of pyrite and graphite, the other on HCl‐leached coal. A simple correction method for the effects of ash absorption was demonstrated. Differences between the Mössbauer and ASTM wet chemical methods for analyzing pyritic sulphur in coal were evaluated. Good agreement was shown, provided residual undissolved pyritic in the ASTM method is taken into account. Analysis of spectrometr capability indicates a routine sample could be analyzed in about 10 minutes.