Nanostructures of rare-earth metals in the coals of the shubarkol deposit

Abstract

The rare metals of the Shubarkol coal deposit have a surface layer thickness of about 3 nm, i.e. are nanostructures. The thickness of the surface layer of the coal itself is of about 0,2 µm, i.e. it is a mesostructure. The pore radius in the coal substance is 30,6 nm, which corresponds to mesopores, and the specific surface area of coal is 857 m2/g. Rare metals, either in the form of pure impurities (~ 3 nm), or in the form of oxides (~ 7 nm), or in the form of organic impurities (~ 1-3 nm), freely enter into mesopores of the coal. The forms of occurrence of uranium and rare metals in the coals of the Shubarkol deposit indicate that their concentration in the coal is due to the leading role of the hydrogenous mechanism. In the d(I) layer, all rare metals are nanoluminophores, which can be considered as sensitive molecular probes for studying the structure of coal. It is emphasized that the influence of size effects on kinetics of the luminescence decay and anomalous thermalization of rare earths can be easily obtained experimentally. The fractal dimension of Shubarkol coal is 2,60, which is lower than that of anthracite – 2,74. In the mesoporous structure of Shubarkol coal, the adsorption of rare metal impurities is highly developed due to the formation of adsorption layers on the surface of these mesopores, which lead to volumetric filling of these pores by mechanism of the capillary condensation.

Keywords

• surface layer
• rare metal
• nanostructure
• mesostructure
• atomic volume
• size effect
• carbon matter
• fractal