Hymatomelanic and Humous Acids in Lignite: Spectral Analysis

Humous and hymatomelanic acids are obtained by separating humic acids from Kansk-Achinsk and South Ural lignite. The yield of humic material is greatest for naturally oxidized lignite from the Tisul’sk field in Kansk-Achinsk Basin: 60.9% humic acids, 49.6% humous acids, and 11.3% hymatomelanic acids. The acid fractions are characterized by Fourier transform IR (FTIR) and 13C NMR (CPMAS) spectroscopy, as well as elemental and technical analysis. The elemental composition and structural group composition of the humic, humous, and hymatomelanic acids differ significantly. The composition of the humic acids is complex, with aromatic and aliphatic fragments. The hymatomelanic acids consist mainly of aliphatic fragments. The content of carbon and aromatic fragments is higher for humous acids, which are insoluble in alcohol, than for hymatomelanic acids.