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A study of thermophysical and ecological properties of highly loaded (50% mass.) coal-water slurry based on Kansk-Achinsk brown coal and distilled water (coal-water slurry fuel -CWSF) with exposure of used water to cavitation-treatment, microwave processing of coal powder, T-900 nanocarbon additions is presented. The study shows that under the conditions of this experiment the thermal physical properties of CWSF are most affected by the use of cavitation-activated water.

Among the new coal technologies the burning of low-grade coal in the form of coal-water slurry fuel (CWSF) is of a great interest. The basis of CWSF is a highly concentrated coal-water slurry consisting of finely ground coal, water or other liquid and plasticizing agents. The development of CWSF technology is highly relevant for solving global problems of resource conservation and ecology. The study is dedicated to CWSF properties with respect to Kansk-Achinsk coal and water. This paper presents the results of the influence of CWSF’s preliminary cavitation water treatment on the combustion dynamics of fuel, (including the features of the combustion temperature trends, delayed ignition time and time of complete combustion) and on its environmental characteristics. A rotary-type hydrodynamic oscillator at high angular velocity (10000 rpm) was used in supercavitation mode. It is shown that the technology of cavitation water treatment leads to a change in the dynamics of CWSF’s combustion and to an additional decrease in NOx emissions by 1.6 times, CO2 by 1.3 times.

Variation of surface tension coefficient σ of distilled water under high-energy impact (hydrodynamic cavitation) was studied by the ring separation method. Force impacts on surface tension of water have been studied experimentally. Conditions have been found under which the surface tension coefficient σ decreases to 20%. The paper explains the produced results on the basis of cluster theory of water structure. The experimentally produced relaxation time of the surface tension of cavitation-activated distilled water to initial value has been found to be 3.5 hours.

Changes in the properties of brown Kansk-Achinsk coal after exposure to microwaves have been studied using scanning electron microscopy (SEM) and electron magnetic resonance (EMR). The size composition of the samples has been investigated. The structure of coal has been found to be similar to the structure of multicomponent organic glass. The analysis of the changes in the EMR spectra of the coal samples (300 K, 83 K) exposed to microwaves has been found to gather information about the structural transformation taking place in the coal matter.