| Autor: |
Orekhov, Vladimir, Bobkov, Vladimir, Morgunova, Elvira |
| Předmět: |
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| Zdroj: |
AIP Conference Proceedings; 2023, Vol. 2999 Issue 1, p1-8, 8p |
| Abstrakt: |
The paper investigates the following thermophysical characteristics: heat capacity and thermal conductivity of phosphorus-containing ore materials in the temperature ranges and heating rates of existing heat-technological devices for the heat treatment of ore raw materials. A significant effect of the endothermic heterogeneous reaction of carbonate dissociation on these thermophysical characteristics has been found. The analysis of experimental data and the results of solving the heat conduction inverse problem made it possible to scientifically substantiate and comprehensively study the type and parameters of the kinetic equation of carbonate dissociation heterogeneous reaction and the phosphorites thermophysical characteristics. It has been established that in the temperature range of carbonate minerals thermal dissociation, the thermal conductivity coefficient changes several times, and the true volumetric heat capacity decreases, depending on the concentration of carbonates, while the maxima of the effective heat capacity exceed the values of the true heat capacity. A significant effect of the heterogeneous decarbonization process on the thermal conductivity was noted for all the samples under study at the initial stage of this chemical energy-technological process. The decrease in the reacting material thermal conductivity is due to a change in the thermal contact of carbonate grains with the host phosphorus-containing rock at the beginning of the chemical energy-technological process of firing and the replacement of highly thermally conductive crystalline inclusions with a powder-like finely dispersed product with low effective thermal conductivity. It was revealed that the thermal conductivity of phosphorus-containing ore raw materials during high-temperature roasting is less than after reheating, due to the influence of interdependent factors-the flow of carbonate dissociation gaseous products directed towards the heat flow and an increase in the thermal conductivity of the calcined ore materials as a result of their sintering. Such a comprehensive joint study of heat and mass transfer and of the chemical-energy processes turned out to be appropriate, both in terms of reducing the amount of work and obtaining more reliable information. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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