| Titanium has extensive application in the field of daily life as well as in aerospace, chemical engineering and metallurgy industry due to its series of excellent performance. However as a result of the complexity of Kroll process which is currently the industrial process for Titanium production the producing cost of titanium can hardly be decreased, which significantly limits the application of titanium. Therefore, improvement of titanium extraction technology is the main path to make wider use of titanium.Kroll process is the primary process for producing Titanium industrially nowadays. Additionally, many researchers put forward lots of new methodologies which are simpler and lower-cost for titanium extraction. These methods come down to electrolysis process and metallothermic reduction process. The most typical representative of electrolysis is FFC process and of metallothermy is the PRP process using calcium for reductant PRP process uses calcium vapor to reduce the perform containing TiO2 in airtight reactor to produce Ti powder.These processes haven't got application in industrial production as a result of some problems hard to deal with in themselves.Based on the principle of thermal reduction, Experiment explored reduction of TiO2 with the carbon and metal (magnesium, calcium) steam in a closed reactor, the possibility of joint preparation of titanium method also were studied. In the experiment, we have explored the preparation of titanium conditions by changing the reaction conditions (temperature, holding time, adding additives or otherwise).Then analysis were taken such as SEM, EDS, XRD and chemical composition analysis. The results show that: calcium-thermal reduction temperature is 1000℃the best reaction time is 6h to get titanium; for magnesium-thermal reduction optimum reaction conditions are for temperature 900℃and reaction time is 6h. Titanium powdered were gotten under these conditions, The obtained titanium with calcium-thermal method which the particle size for 3.06-10.23μm, at purity of 97.68%(Wt%), while the magnesium thermal method for 4.06-11.32μm, which purity of only 71.35%(Wt%). Meanwhile, factors of the reaction temperature, reaction time and the impact of additives were explored in the experiments. Such as at temperatures of 1200℃and higher stability of MgTiO3, MgTi2O4were obtained, which will hinder of reducing reaction proceeded. Therefore, the appropriate reduction temperature should be lower than 1100℃. For the carbon thermal reduction method, experiments results show that:Carbon is not a good agent for reducing TiO2, To restore TiO2 using toner (coal) in the temperature range of 1400℃-1600℃, which mainly products were TiC and a small amount of low-cost titanium oxide. It's feasible for metal thermal reduction method in the present experimental conditions, for reducing costs adding a process of metal preparation. We proposed using of ferrosilicon and calcium oxide to obtained calcium firstly, then using calcium to restore titanium dioxide. Experiments show that:It's feasible for joint preparation of titanium in thermodynamically and the method lower energy consumption, process shorter, less pollution advantages than industry process. However, there are some practical issues need to be further improved.Thermodynamic calculation and experimental results show that:For carbon thermal reduction method to obtain the existence of titanium in process is difficult, but using of the method can be prepared TiC; "Calcium-thermal combined method" is feasible in the thermodynamic, but to obtain high purity titanium metal was also need to continuously improve the experimental crucible; Titanium can be obtained using of metal calcium and magnesium, the reaction process, reaction time, reaction temperature all can affect the process. Therefore, using self-made crucible in a vacuum, and using metal (calcium and magnesium) to preparation of titanium have a greater research significance. |
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