Study On The Application Of Thermodynamics Of Irreversible Processes In Metallurgy

Irreversible phenomena are common in the metallurgical systems. Heat transfer, mass transfer and chemical reactions in pyrometallurgy and hydrometallurgy are typical cases of irreversible processes. It is significant in theory and practice to introduce thought and method of thermodynamics of irreversible processes to metallurgical systems.Based on the assumption which the thermodynamic flow is the function of the thermodynamic forces in the theory of irreversible processes, a chemical rate equation was set up in single chemical reaction homogeneous system. The equation is different from that of linear thermodynamics theory because of its high term. The equation has been applied to water-gas reaction with a quintic expression obtained in high conformity to measured data. The thrice expression was obtained in agreement with the experimental data when the equation was used to the reaction of nitrogen monxide and oxygen .The equation was applied to sodium permanganate for phenol destruction and sodium permanganate for aniline destruction separately, the thrice expressions which were conformed to the experimental data were obtained at different initial reaction conditions in different reaction systems.The coupled diffusion model was given according to irreversible thermodynamics. The coupled three-components liquid diffusion was investigated and the rigorous solutions of the model subject to the homogeneous boundary conditions of the first kind were derived by employing Hankel transform technique and the standard technique resolving ordinary differential system. Then the case computations were conducted. The calculation results showed that when the cross coefficients were close to 5%-7% of the main coefficients, the significant effect of coupled diffusion on the concentration profiles of components was observed.The kinetic equation was given to express the reaction rate in homogeneous system including chemical reaction and diffusion by irreversible thermodynamics. The equation was applied to the catalytic reaction of hydrogen peroxide, some quartic expressions were obtained in conformity to the experimental data at 298K and 308K correspondingly. The influence of temperature on term was discussedThe kinetic equation was set up at different control factors in liquid-liquid system, and applied to the manganese oxidation reduction reaction. The obtained thrice...