Process and system for purifying titanium tetrachloride by removing vanadium

Abstract

The invention discloses a process and a system for purifying titanium tetrachloride by removing vanadium. The process comprises the following steps of: conveying coarse titanium tetrachloride to a circulating tank via a coarse titanium tetrachloride storage tank, conveying the coarse titanium tetrachloride to a pipeline of a heat exchanger through a feeding pump, heating coarse titanium tetrachloride materials, controlling pressure of a material outlet of the heat exchanger, feeding the heated coarse titanium tetrachloride materials to enter a flash tank via the heat exchanger outlet, and feeding into a vanadium-removing reaction tower after vaporizing in the flash tank; conveying mineral oil to the vanadium-removing reaction tower, contacting, exchanging heat and controlling temperature and pressure in the vanadium-removing reaction tower to carry out a reduction reaction; generating titanium tetrachloride slurry at a tower bottom, discharging titanium tetrachloride gas from a tower top and entering a cooling kettle to obtain titanium tetrachloride. The system is composed of a coarse titanium tetrachloride storage tank, a circulating tank, a feeding pump, a heat exchanger, a flash tank, a vanadium-removing reaction tower, a cooling kettle and a chlorinating and dust-collecting part. The process and system have the advantages that the scabbing is effectively prevented, the heat exchange efficiency is enhanced, the service life is prolonged and the vanadium is effectively removed, the vanadium-removing process is safe and reliable and the working condition is improved.

Description

technical field [0001] The invention relates to a process and system for purifying and removing vanadium from titanium tetrachloride. Background technique [0002] Titanium tetrachloride is the main raw material for producing sponge titanium and titanium dioxide. In the production process of titanium tetrachloride, the raw materials contain a variety of metal and non-metallic impurities, which will be brought into titanium tetrachloride, which will affect the quality of titanium sponge and titanium dioxide produced in the subsequent process. Such as the presence of yellow vanadium oxychloride (VOCl) in titanium tetrachloride 3 ), will increase the hardness of sponge titanium in the process of producing sponge titanium, and will affect the whiteness of titanium dioxide in the process of producing titanium dioxide. Therefore, titanium tetrachloride needs to remove the vanadyl trichloride impurity, so that its content can meet the production requirements of the subsequent pro...

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Problems solved by technology

[0003] The difference in boiling point and relative volatility between titanium tetrachloride and vanadium oxytrichloride is small, therefore, it is not suitable for separation by physical distillation.

In actual production, when heating the mixture of titanium tetrachloride and mineral oil, the steam heating or electric element heating tube is generally immersed in the evaporation kettle. Since the heating tube is placed in the mixture, and the flow rate in the kettle is small, the steam will The consumption is more than 230kg / ton of titanium tetrachloride, and the heat exchange efficiency is low; moreover, the heating tube is easily scabbed, which affects the heat exchange effect, and a large amount of titanium tetrachloride fume will be generated during the disassembly process, and the working environment is harsh

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