The paper presents the review of researches of the ignition and combustion stabilization of the water-coal fuel. Working models of plants are described, the results of their tests in laboratory and industrial conditions are given. Two schemes of the WCF ignition are presented - one with burners with hydrocarbon (solar) fuel, and the other with the system of plasma ignition. Advantages of these two systems are described. The promising future of the SPI application in industrial conditions is demonstrated

-It is shown that use of coal-water slurry fuel (CWF) is most preferable for reduction of sulfur oxide content during combustion of coal fuel by feeding of sulfur capture agents (SCA) in the burning area. The technique of thermodynamic analysis of chemical reactions in the process of CWF burning was developed. In this case, the optimal temperature conditions have been determined as required for the effective reduction of sulfur oxides in flue gases when using different types of SCA. According to the results of calculating the composition of CWF combustion products when entering various substances in the burner space as SCA it has been determined that magnesite, calcite, and dolomite are the most effective natural minerals. The reliability of the results obtained is confirmed by experimental studies of burning CWFs prepared from Bulgarian high-sulfur coal Keywords-sulfur capture agent; water-coal slurry fuel; thermodynamic analysis; vortex combustion of coal fuel

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Abstract. It is shown that an effective way of burning high sulfur coal is to burn coal-water slurry fuel (CWF) prepared on its basis containing a sulfur capture agent (SCA) entered in the slurry at the stage of preparation. The technique of thermodynamic analysis of chemical reactions during CWF burning has been developed including burning in the presence of SCA. Using the developed calculation program, the optimal temperature conditions have been determined as required for the effective reduction of sulfur oxides in flue gases when using different types of SCA. According to the results of calculating the composition of CWF combustion products when entering various substances in the burner space as SCA it has been determined that magnesite, calcite, and dolomite are the most effective natural minerals. The analysis of calculated and experimental data proves the efficiency of SCA addition as well as validity of the obtained results.

Abstract. Effective utilization of ash-and-slag waste generated by coalfired power plants can help significantly to reduce the negative impact on the environment and improve their economic performance. Studies have been made of the mineralogical composition of ash-and-slag wastes obtained after the combustion of water-coal fuel based on fine-dispersed coal-washing waste (filter cake) in a specially designed boiler with a vortex combustion system. The possibility of effective use of ash-and-slag wastes for the production of building materials, primarily mortar mixes, widely used for mining works on mine openings, laying the worked out space, etc. (high content of silicon oxide and aluminum oxide is combined with a low carbon content in other words a negligible unburned carbon loss). The optimum percentage ratio of the initial components of the filling mixture based on ash-and-slag wastes and crushed rock (granulated slag) has been established. The results of experimental tests of hardening tabs on the strength under uniaxial compression are presented. It has been established that a sample containing 18% of ash-and-slag wastes, 33% of a granulated slag and 19% of cement, corresponds to the required technological parameters for the strength and cement content.

The baseline conditions of technology for producing and burning coal-water slurries in Russia and foreign countries is exposed. The technological and economic efficiency of using this technology for the coal processing and cleaning waste disposal is shown at experimental and industrial facilities. The feasibility studies of the technology usage at large Kuzbass thermal power plants are presented. The possibility of solving a serious environmental problem of reducing the storage of the most coal washing toxic waste volume in the areas where coal processing plants and coal mining enterprises are located is demonstrated. It is shown that on the basis of these wastes, it is possible to prepare a suspension coal-water fuel with a solid phase content of 56-59%, with the required structural and rheological characteristics and a lower calorific value of up to 13 MJ/kg. The boiler with a thermal capacity of 0.58 MW with an eddy combustion system, which effectively operates on coal-processing waste fuel is designed, manufactured and tested. The results of the boiler operation on the specified fuel showed its high efficiency (efficiency is 83-85%) with the level of harmful emissions in the flue gases significantly lower than the permissible values.

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