Contents of major and trace elements in feed coals from Turkish coal-fired power plants

This preliminary study focuses on the determination and comparison of major and trace element concentrations in feed coals from ten Turkish coal-fired power plants (Cayirhan, Seyitomer, Tuncbilek, Orhaneli, Soma, Yatagan, Yenikoy, Elbistan, Kangal and Catalagzi). Thirteen samples of feed coal were collected from the units of these plants and studied using proximate and ultimate analyses, X-ray powder diffraction, inductively coupled plasma-atomic emission spectrometry, inductively coupled plasma-mass spectrometry, and scanning electron microscopy with energy-dispersive X-ray microanalysis techniques. The feed coals have high moisture (14-47%) contents, high ash (23-64%) yields, and a broad range of total sulfur contents (0.4-4.8%), and gross calorific values (1370-4980 kcal/kg). The mineral matter of the feed coals is mainly made up of clay minerals (smectite, illite, kaolinite/chlorite), quartz, feldspar, calcite, dolomite, pyrite and gypsum. Moreover, some lignites such as Seyitomer, Tuncbilek and Soma contain appreciable contents of siderite; the Elbistan low contents of aragonite; the Cayirhan high contents of zeolites (clinoptilolite/heulandite and analcime). Most of the feed coals proved to be enriched relative to Cr, Cs, Mo, Ni, Rb, Th, U and V. Furthermore, concentrations of As, Co, Cu, Ga, Mn, Li, Sc, Sn, Ta, Tl and some rare earth elements in some feed coals exceed the currently available ranges for most world coals. (C) 2000 Elsevier Science B.V. All rights reserved.