A technology of briquetting of sub-standard coal of Kazakhstan fields to obtain high-quality briquetting fuel has been developed. A modifying additive in the form of oil residues has been selected, that make it possible to obtain a binder composition for brown coal briquetting. The material for the preparation of coal briquettes is coal fines from dry, poorly sintered coals, which cannot be used for direct combustion in the furnace. The optimal parameters for obtaining high-quality fuel briquettes have been determined.
Boiler units at Ukrainian thermal power plants need to be modernized or replaced in the short run, as this is important for the national energy security. The authors determined one of possible ways to improve the efficiency indicators of coal-fired boiler units and power generating units as a whole up to the values exceeding the design ones. This variant of improvement consists in abandoning the technology of using flue gas as drying agent in pulverized coal systems and replacing it with direct discharge of the gas flow into the boiler furnace.
A presence of microscopic fungi, heterotrophic bacteria, as well as neutrophilic and acidophilic chemolitotrophic bacteria was determined in coal microbiocenosis. The largest and most active towards pyrite sulfur removal is the Acidithiobacillus genus. Heterotrophic bacteria have the biggest potential when it comes to removal of organic sulfur. Preceding treatment of coal with “silicate” bacteria from the Bacillus genus will allow to use coal microbiocenosis for its biodesulfurisation at its full potential.
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.