![Sample our Engineering & Technology journals, sign in here to start your access, latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5933/TOC-Subject-Sample-2021-Engineering-Tech.jpg"})
In this study, lignite samples were collected from the Ptolemais region, northern Greece, homogenized, crushed to less than 1 mm, and separated in three density fractions using heavy media. The mineralogical investigation of the density fractions showed a predominance of pyrite in the light fractions, a fact that might be related to either the poor separation or pyrite being trapped between relatively large pure coal particles during the density fractionation. The geochemical analysis revealed that arsenic (As) and boron (B) tend to concentrate in the lighter fractions, while iron (Fe), magnesium (Mg), nickel (Ni), cobalt (Co), manganese (Mn), lead (Pb), and chromium (Cr) are associated with the heavier fractions. No clear indications were drawn for calcium (Ca), selenium (Se), copper (Cu), zinc (Zn), and phosphorus (P).
Acknowledgments
The author is indebted to Dr. Wolfram Müller, Mineral Processing Institute, RWTH-Aachen, Germany, for the conduction of the density-fractionation analysis. A post doc fellowship awarded to A. Iordanidis by the Hellenic National Scholarship Foundation (IKY) is gratefully acknowledged.