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.
Mechanism functions and kinetic parameters of AlOOH（boehmite or diaspore） dissolving in sodium hydroxide solution were researched.The mixture of boehmite or diaspore and caustic solution was scanned by high-pressure differential scanning calorimetry（DSC） instrument with heating rate of 10 ℃/min,and differential equation method was used to analyse the DSC curves,combining with iterative method and linear least square method.The most probable mechanism functions for both boehmite or diaspore and caustic solution reactions were logically selected from 30 types of non-isothermal kinetics differential equations,according to the calculated results obtained by Matlab program.The most probable differential mechanism function of boehmite dissolving in caustic solution is f（α）=1-α,which reveals the first-order reaction with apparent activation energy of 79.178 kJ/mol and the preexponential constant 1.031×108 s-1.The function,f（α）=2（1-α）3/2,can describe the dissolution of diaspore sample in sodium hydroxide solution.The calculated results of kinetic parameters are apparent activation energy of 73.858 kJ/mol,preexponential constant of 5.752×107 s-1 and reaction order of 1.5.
