Authors: N.I. Fedorova, MalishevaV.Yu., Z.R. Ismagilov

Title of the article: Ir spectroscopy of coal inertinites of various stages of metamorphism

Year: 2018, Issue: 3, Pages: 86-92

Branch of knowledge: Chemical technology

Index UDK: 662.74:543.422

DOI: 10.26730/1999-4125-2018-3-86-92

Abstract: Actuality of work: fossil coals present a complex composite system, consisting of organic micro components in the form of macerals and mineral inclusions. Therefore, in order to establish the rational direction of the use of coals in various processes, knowledge of the chemical structure of their organic mass is necessary. In recent decades, research in the field of coal chemistry has been aimed at studying the composition and properties of the vitrinite group of macerals, since they determine the technological properties of coals, for example, used in coking. However, the inert component, the inertinite group, has not yet attracted such close attention. In this paper, we present the results of an investigation of inertinite components of coals by infrared spec-troscopy. Inertinite concentrates were used as research objects; they were isolated from humid coals of various stages of metamorphism by means of their stratification in a mixture of carbon tetrachloride and benzene with a density of 1.40-1.45 g/cm3. The choice of the density of the solution was determined by the fact that the maximum content of inertinite inclusions is concentrated in fractions of 1.40 g/cm3. Research methods: technical, elemental, petrographic analyses infrared spectroscopy. Results: Using a set of analytical methods, seven samples of inertinite concentrates isolated from coals of various metamorphic stages were characterized. The ash content of inertinites was less than 10%. With the growth of the metamorphism stage (an increase in the value of Ro,r), the yield of volatile substances and the atomic ratios H/C and O/C decrease in the samples studied. The structure of inertiniteswas fixed in IR spectra with D3040, D2920, D1620, D900-700 optical frequencies. The investigated samples were characterized by a significant intensity of absorption bands peculiar to aromatic structures (D3040, D1620, D900-750 cm-1). To characterize the chemical maturity of inertinites, the D3040 / D2920 pa-rameter (the ratio of the optical densities of CH unsaturated and C-H aliphatic bonds) was used. It was estab-lished that the D3040 / D2920 parameter increases with the vitrinite reflection index. The data obtained showed that a reduced number of aliphatic groups and a more developed spatial polyconjugation system characterize the components of the inertinite group.

Key words: fossil coals stages of metamorphism inertinite vitrinite elemental composition IR spectroscopy

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