On the interactions between strength and petrology of Pennsylvania anthracite

Abstract

Six blocks of anthracite, each from a known seam and mine location, were tested for their unconfined compressive strength and elastic modulus. The maceral content and the proximate analysis of the test specimens were examined after the strength tests were completed. The coal rank (2.84 to 5.84%Rmax), the maceral composition (41.9–88.6% vitrinite (mineral-free basis), and as-received ash content (2.76–28.29%) are not good predictors of the strength for these samples. Instead, the highest compressive strength and elastic modulus samples were the anthracites with the highest ash yield. Among the lowest ash specimens, compressive strength decreases with an increase in the ratio of (telovitrinite + fusinite + semifusinite)/detrovitrinite). The cleats and the inorganic (mineral) and organic (maceral) composition of megascopic and microscopic lithologies likely contributed unquantified variables to those determined in this study.