Aim. Experimental study of main technological parameters of a ball mill during coal milling at a thermal power plant and development of a mathematical model for the mill on the basis of the obtained data. Method. Based on the analysis of the energy flows in the ball mill the relation between the vibration energy of the mill body and the amount of the material in the mill is defined. Experimental study, i.e.
The effect of oxidant composition on the oxidative desulfurization of low grade coal has been studied to obtain raw materials for the production of pulverized coal. The experimental-statistical model has been developed that allowed to establish optimum conditions of the investigated process.
The reactions of coal with the materials used in determining the ignition temperature of unoxidized coal were analyzed. The ignition temperatures of various types of coal from Ukraine, Russia, Canada, Australia, the Czech Republic, Poland, and Indonesia were determined. The influence of the composition, structure, and properties of the coal on its ignition temperature was assessed.
This research displays the state of metallurgical coke production in Ukrainew with special attention to the raw material base for production of coke and its quality. Besides the following essay deals with the detailed analysis of preparation methods of coal charge for coking, including thermal treatment and stamp charging and formulates the main ways of upgrading coke quality considering the rational technology of coking.
Regularities of changes in solid fuel elemental composition during metamorphism have been investigated. A mathematical model describing these regularities as functions of Cdaf has been developed. Experimental data of artificial coalification confirm that it is an experimental model of natural metamorphism.
Dynamics of coal chemical structure during metamorphism has been evaluated using mathematical model of metamorphism kinetics attached to the time axis in accordance with artificial coalification data.
The article deals with the hypothesis of the influence of coals mineral components on coke reactivity. It has been shown that the reaction between carbon and carbon dioxide proceeds in kinetic area and its rate depends upon total ash content of coked coal. The data showing catalyst effect of coal mineral components upon their organic mass pyrolysis and consequently upon coke reactivity have been presented.
“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.