coal

“Jumps” in structure composition and properties of solid fuel have been determined using the model of metamorphism dynamics. For these “moments” of the geological age the elemental composition and structural peculiarities of “molecules” have been determined and approved by stoichiometric equations of the reactions, material balances of the stages and the agreement between the combustion heat of model compounds and coals of similar elemental composition. 

The research works dedicated to the formation regularities of solid fuels chemical structure were analyzed. Modern conceptions of coals chemical structure, which are becoming deeper owing to tooling growth and facts accumulation, were examined by means of critical comparison of different hypothetical models of solid fuels “molecular” structure. The most general points of the respective theories were formulated, according to which “soft” influence on coal structure primary elements bonds system allows bringing its chemical potential to the maximum.

The conditions providing proceeding of the reactions between pyrite sulphur of medium-metamorphized coal and air-steam mixture in the kinetic area have been found. Experimental-statistical mathematical model has been designed. The optimal factors of medium-coalificated coal oxidative desulphurization have been determined on its basis. Under optimal conditions two samples of coking coal have been desulphurized. These samples will be used as components of the coal charge in the production of special types of coke.

An experimental statistic model of power-generating coal oxidative desulphurization has been developed and its adequacy has been proved. On the basis of the proposed model the desulphurization optimal conditions for three samples of power-generating coal were determined. The low-sulphur solid fuel with the content of general sulphur of 1.0–1.5 mas % was obtained under established optimal conditions.

The effect of pyrite size and distribution character, as well as the amount of inorganic matter on the removal degree of sulphur from coal during its oxidative desulphurization and benefication has been studied. The efficiencies of oxidative desulphurization processes for different types of the initial and concentrated black coal have been compared.

The desulphurization process of different coal types has been studied. The coal was treated by air-steam mixture in the fluidized-bed reactor under the conditions similar to isothermal ones. The influence of temperature and oxidant composition affecting the pyrite (which is the coal component) chemical conversion on the desulphurization efficiency has been investigated for coals with different metamorphism degree.