| With the development of science and technology, different nano and micron scale materials with special constructions and functions were developed by scientist, but the biggest problem is how to produce these new materials in large quantity, this make the chemical engineering important. However, from the point of view of chemical engineering, fluid is the main object in previous research and the control variables are temperature, pressure, composition etc. So it is a great challenge for traditional chemical engineering to deal with the new solid materials. This naturally becomes a hot spot in recent chemical engineering researches.Titanium dioxide whisker is a kind of high performance material, which is in micron scale and takes on complex structure. The hydration process is most important part for the large scale preparation of titanium dioxide whisker, generally, it is also most difficult, because it is a complex, multifactor induced solid-liquid ion exchange process. Under different conditions of hydration, different whiskers can be obtained, such as K2Ti4O9, K2Ti6O13, K2Ti8O17 and H2TiO9 In the previous work in our group, it is found that there is a relationship between the consistence and structure of whisker and the consistence of solution, so it is available to control the structure and consistence of the solid by controlling the consistence of the solution. Based on this knowledge, the remaining problem is to find the suitable operation variable in industry process.In this thesis, a thermodynamics model and a kinetics model are established to describe the hydration progress quantitatively.Based on the phase equilibrium theory, the hydration process is regard as a solid-liquid phase equilibrium progress consisting of a solid-phase thermodynamics equilibrium and a mass equilibrium between the solid and liquid phase.The solid-phase thermodynamics equilibrium of titanium dioxide whisker is worked out by previous researchers in our group. However, the operation variable in industry process is hard to find for the lack of the solid-liquid mass balance model. Via the study in this thesis, it is found the solid-liquid equilibrium stage algorithm is a useful tool for this problem.In this thesis, an integrated thermodynamics model for hydration process, which can be used in the description of the process in hydration thermodynamics equilibrium, is established by combing the solid-liquid equilibrium stage algorithm and the model of solid phase thermodynamics equilibrium for titanium dioxide whisker. Based on this model, the pH value and the quantity of water are choused as the control variables and it is also found the influence of pH is bigger. The mole ratio of TiO2/K2O in initial raw materials has not remarkable influence for the product quantity of hydration andthe proper chlorhydraic acid concentration is 0.1M. The optimal condition for 99% K2Ti6O13 and K2Ti8O17 are respectively pH 9.3-9.9, water usage 10ml/g and pH 6.6-7.0, water usage lOml/g. A revised model for hydration thermodynamics under natural leaching-out condition is also given in this thesis. The optimal condition for pure K2Ti4O9 whisker is 10ml/g KOH solution (0.2M). The coupled methodology of H2Ti4O9 whisker and K2Ti6O13 whisker is established in this thesis.Because the online measurement by general spectrophotography is difficult, a new method based on the online measurement of K2SO4 crystal dissolution kinetics by ion selective electrode is established. The statistical velocity theory is also used in this method.The results in this thesis show that, the control step of hydration of titanium dioxide whisker is the surface reaction process in solid phase, the hydration velocity in acid solution is quicker than that in alkaline solution. The reaction velocity increased with the decrease of pH or the increase of initial water usage, but the influence of pH is rather larger.In the preparation of K2Ti6O13 and K2Ti8O17 whiskers, the pH of solution must be calculated by the method above to control the whole hydration progress, a...
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