Abstract

A limited investigation was undertaken to determine the hardness and other properties of coal from three coalfields; two in Utah and one in Colorado. The investigation had two aims. First, to obtain information on the relationships between the hardness properties of the coal beds and other coal quality parameters such as reflectance and proximate analysis to determine whether empirical correlations exist between those properties. Second, to develop a database of hardness properties for individual coal beds as a possible aid in identification and correlation. Sixty-six samples were involved, taken from five coal beds in the Book Cliffs coalfield, three beds in the Wasatch Plateau coalfield, and one coal bed in the Colorado’s Carbondale coalfield. Two hardness tests were employed – Vickers microhardness and Shore rebound. Proximate analysis and reflectance measurements were made for correlation purposes. A relationship was determined between hardness and coal rank which is similar to that reported by other investigators on non-Utah coals. The results from the Upper and Lower O’Connor and Sunnyside beds indicate that this technique can be used for identification of coal beds. It appears that these hardness techniques could be developed into methods for predicting coal quality.