Characterization of Turkish coals: a nationwide perspective

The U.S. Geological Survey (USGS) and the Turkish General Directorate of Mineral Research and Exploration (Maden Tetkik ve Arama Genel Mudurlugu, MTA) are working together to provide a better understanding of the chemical properties of Turkish coals from major Turkish lignite producing areas. The coals in Turkey are generally low rank (lignite or subbituminous) formed in several different depositional environments at different geologic times and have differing chemical properties. Eocene coals are limited to northern Turkey; Oligocene coals, found in the Thrace Basins of northwestern Turkey, are intercalated with marine sediments; Miocene coals are generally located in Western Turkey. The coal deposits, which have limnic characteristics, have relatively abundant reserves. Pliocene-Pleistocene coals are found in the eastern part of Turkey. Most of these coals have low calorific values, high moisture, and high ash contents. Analysis of 143 coal channel samples (most are lignite and subbituminous in rank, but a few are bituminous and one is anthracitic in rank) has been completed for up to 54 elements and other coal properties using a variety of analytical techniques, including inductively coupled plasma emission and mass spectrometry, instrumental neutron activation analysis, and various single element techniques and ASTM standard procedures. Many of these coals have elemental concentrations similar to U.S. lignites found in the Gulf Coast and Fort Union regions, However, maximum or mean concentrations of B, Cr, Cs, Ni, As, Br, Sb, Cs, and U in Turkey are higher than the corresponding maximum or mean values found in either the Fort Union or Gulf Coast regions. (C) 2004 Elsevier B.V. All rights reserved.