Crystal form regulation and control method for producing titanium dioxide through chlorination process

Abstract

The invention discloses a crystal form regulation and control method for producing titanium dioxide through the chlorination process. The method includes the steps that chlorine of 50-80 DEG C and titanium tetrachloride gas of 400-500 DEG C are evenly mixed and then introduced into an aluminum trichloride generator under the pressure of 200-800 kPa; after quantitative powdered aluminum in the aluminum trichloride generator and the chlorine in the mixed gas are reacted to produce aluminum trichloride gas, and the aluminum trichloride gas is led to an oxidation reactor together with the titanium tetrachloride gas; the titanium tetrachloride gas mixed with aluminum trichloride carries out a gas phase oxidation reaction with oxygen which is preheated to be 1600-1800 DEG C, and the titanium dioxide with the rutile type content being 90%-99.99% is obtained after cooling and gas-solid separation. According to the method, the aluminum trichloride and the aluminum trichloride produced in the aluminum trichloride generator are evenly and fully mixed, and the rutile type content in the titanium dioxide can be controlled by adjusting the addition amount of the powdered aluminum in the aluminum trichloride generator. The method is low in cost, easy to operate, and capable of regulating and controlling the rutile type content in the titanium dioxide and meeting the application requirement of high-quality rutile type titanium dioxide through the chlorination process.

Description

technical field [0001] The invention belongs to the technical field of chemical industry, and relates to a method for producing titanium dioxide by a chlorination method, in particular to a method for controlling crystal form of producing titanium dioxide by a chlorination method. Background technique [0002] Titanium dioxide has three crystal structures, namely brookite, anatase and rutile. In particular, rutile titanium dioxide has high refractive index, large dielectric constant and excellent optical properties, and is widely used in coatings, plastics, inks, paper and other industries. [0003] In the process of preparing high-grade rutile titanium dioxide by chlorination, gas-phase oxidation of titanium tetrachloride is a key step in the preparation of titanium chloride. Titanium tetrachloride and oxygen undergo an oxidation reaction in an oxidation reactor to form titanium dioxide, and the crystal structure of titanium dioxide mainly depends on the initial temperatur...

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Problems solved by technology

[0004] Since the gas-phase oxidation reaction is very fast and the reaction time is extremely short, it is completed within one tenth of a second. Even if the reaction temperature is increased to 1200°C-1300°C, there is not enough time to complete the transformation of the crystal form, resulting in gas phase oxidation. The rutile content of the oxidized titanium dioxide crystal structure only accounts for 60%-70%, which directly affects the application performance of the product

In the traditional chlorination method to produce titanium dioxide, either no crystal form conversion agent is added, or the crystal form conversion agent cannot be fully and uniformly mixed with the titanium tetrachloride reactant, resulting in the rutile content of the titanium dioxide product not exceeding 90%. %, cannot be used as high-grade rutile titanium dioxide

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