INTRODUCTION

The mercury concentration in coal varies in a wide range from less then 1 ppb to 300 ppm. Commonly, the total mercury concentration in coal is studied. However, geological processes generate various mercury species in coal and host rocks which can be represented by syngenetic mercury bound to organic matrix; sulfide, silica and carbonate minerals, and by elemental Hg. These species have different matrix binding energy and can be determined by the so-called thermoscanning technique based on the real-time detection of mercury release from a sample during its gradual heating.