Natural rutile and gaseous chlorine with carbon as reductant were used to prepare titanium tetrachloride. Thermodynamics and kinetics of chlorination of Kenya natural rutile particles in a batch-type fluidized bed wer...Natural rutile and gaseous chlorine with carbon as reductant were used to prepare titanium tetrachloride. Thermodynamics and kinetics of chlorination of Kenya natural rutile particles in a batch-type fluidized bed were studied at 1173-1273 K. Thermodynamic analysis of this system revealed that the equation of producing CO was dominant at high temperatures. Based on the gas-solid multi-phase reaction theory and a two-phase model for the fluidized bed, the mathematical description for the chlorination reaction of rutile was proposed. The reaction parameters and the average concentration of gaseous chlorine in the emulsion phase were estimated. The average concentration of emulsion phase in the range of fluidized bed was calculated as 0.3 mol/m^3. The results showed that the chlorination of natural rutile proceeded principally in the emulsion phase, and the reaction rate was mainly controlled by the surface reaction.展开更多
In this paper, the thermodynamics and kinetics of nature rutile carbochlorination in a fluidized-bed were investigated. The thermodynamic calculations of TiO2-C- C12 system show that when C is excess in the solid phas...In this paper, the thermodynamics and kinetics of nature rutile carbochlorination in a fluidized-bed were investigated. The thermodynamic calculations of TiO2-C- C12 system show that when C is excess in the solid phase, titanium tetrachloride and carbon monoxide can exist sta- bly. At high temperature, the reaction with CO as the product is the dominant reaction. The appropriate reaction conditions are as follows： reaction temperature of 950 ℃, reaction time of 40 min, carbon ratio of 30 wt% of rutile, natural rutile particle size of -96 μm, petroleum coke size of -150 μm, and chlorine flow of 0.036 m3.h-1. Under the above conditions, the reaction conversion rate of TiO2 can reach about 95 %. This paper proposed a reaction rate model, and got a rutile chlorination rate formula, which is generally consistent with the experimental data. For the TiO2-C-C12 system, the reaction rate is dependent on the initial radius of rutile particle, density, and the partial pressures of C12. From 900 to 1,000 ℃, the apparent activation energy is 10.569 kJ.mo1-1, and the mass diffu- sion is found to be the main reaction-controlling step. The expression for the chlorine reaction rate in the C-C12 sys- tem is obtained, and it depends on the degree of reaction, the partial pressure of C12, and the size of rutile particle.展开更多
基金Projects(51374064,51004033,51074044)supported by the National Natural Science Foundation of ChinaProject(2012AA062303)supported by High-tech Research and Development Program of China
文摘Natural rutile and gaseous chlorine with carbon as reductant were used to prepare titanium tetrachloride. Thermodynamics and kinetics of chlorination of Kenya natural rutile particles in a batch-type fluidized bed were studied at 1173-1273 K. Thermodynamic analysis of this system revealed that the equation of producing CO was dominant at high temperatures. Based on the gas-solid multi-phase reaction theory and a two-phase model for the fluidized bed, the mathematical description for the chlorination reaction of rutile was proposed. The reaction parameters and the average concentration of gaseous chlorine in the emulsion phase were estimated. The average concentration of emulsion phase in the range of fluidized bed was calculated as 0.3 mol/m^3. The results showed that the chlorination of natural rutile proceeded principally in the emulsion phase, and the reaction rate was mainly controlled by the surface reaction.
基金financially supported by the National Natural Science Foundation of China(Nos.51374064,51004033,and 51074044)the National High-Tech Research and Development Program of China(No.2012AA062303)+1 种基金the National Key Technology Support Program during the 12th Five-Year Plan Period(No.2012BAE01B02)the Fundamental Research Funds for the Central Universities(Nos.N130402012 and N130702001)
文摘In this paper, the thermodynamics and kinetics of nature rutile carbochlorination in a fluidized-bed were investigated. The thermodynamic calculations of TiO2-C- C12 system show that when C is excess in the solid phase, titanium tetrachloride and carbon monoxide can exist sta- bly. At high temperature, the reaction with CO as the product is the dominant reaction. The appropriate reaction conditions are as follows： reaction temperature of 950 ℃, reaction time of 40 min, carbon ratio of 30 wt% of rutile, natural rutile particle size of -96 μm, petroleum coke size of -150 μm, and chlorine flow of 0.036 m3.h-1. Under the above conditions, the reaction conversion rate of TiO2 can reach about 95 %. This paper proposed a reaction rate model, and got a rutile chlorination rate formula, which is generally consistent with the experimental data. For the TiO2-C-C12 system, the reaction rate is dependent on the initial radius of rutile particle, density, and the partial pressures of C12. From 900 to 1,000 ℃, the apparent activation energy is 10.569 kJ.mo1-1, and the mass diffu- sion is found to be the main reaction-controlling step. The expression for the chlorine reaction rate in the C-C12 sys- tem is obtained, and it depends on the degree of reaction, the partial pressure of C12, and the size of rutile particle.
