Mineral matter, major and trace element content of the Afşin–Elbistan coals, Kahramanmaraş, Turkey

Abstract

The Afşin–Elbistan coal basin is one of the most important coal deposits of Turkey. The mineral matter, major and trace element concentrations of the Afşin–Elbistan coals and their modes of occurrence are discussed in this study. The coal seam is located within the Upper Miocene–Pliocene aged Ahmetcik Formation which is represented by fluvial–lacustrine facies. Thickness of the coal zone is 80m, but it reaches 105m in the Kışlaköy sector. A total of 86 samples were taken from the Kışlaköy open-pit mine and from the 14 boreholes drilled by the General Directorate of Mineral Research and Exploration (MTA) for coal exploration. The proximate, XRD, SEM-EDS, major and trace element analyses were conducted on the samples. The studied coals are characterized by relatively high moisture, ash, total sulfur, volatile matter contents and low gross calorific values. The mineral matters of the Afşin–Elbistan coal are represented by calcite, quartz, pyrite, feldspar, aragonite, opal-CT, gypsum, jarosite and clay minerals. Strontium, Rb, Sm, Zr, Hf, Nb, Mo, U, Zn, Pb, As, Mn, Co, Cr and Ni concentrations detected by EDP-XRF are higher than the world brown coal values. Many of the trace elements showing positive correlations with ash content imply inorganic affinity. The element concentrations of the coals are mainly related to the carbonate, silicate, sulfide, phosphate, ore minerals and fossil shells. However, some elements have also organic affinities.