Termoespecificación de mercurio en carbon
The mercury concentration in coal varies in a wide range from less then 1 ppb to 300 ppm. Commonly, th e total mercury concentration in coal is studied. How ever, geological processes generate various mercury species in coal and host rocks which can be represe nted by syngenetic mercury bound to organic matrix; sulfide, silica and carbonate minerals, and by elem ental Hg. These species have different matrix bindi ng energy and can be determined by the so-called therm oscanning technique based on the real-time detectio n of mercury release from a sample during its gradual heating.
The analytical set consists of a standard RA-915M Zeeman AAS mercury analyzer coupled with a PYRO- 915+ pyrolysis attachment. Special automated mode of th e gradual heating of the sample from ambient temperature to 850 O C with a mean heating rate of 0.8 degree per sec is used to detect mercury thermospecies in coal. In the same run, the total m ercury concentration is determined. The analysis of various types of coals reveals variously shaped mer cury thermospectra.