Method for removing vanadium impurity in crude titanium tetrachloride and method for refining crude titanium tetrachloride

Abstract

The invention provides a method for removing vanadium impurity in crude titanium tetrachloride and a method for refining crude titanium tetrachloride. The method for refining the crude titanium tetrachloride comprises the following steps: adding magnesium hydride powder into the crude titanium tetrachloride, so as to reduce vanadium oxytrichloride and / or vanadium tetrachloride in the crude titanium tetrachloride into vanadyl chloride and / or vanadium trichloride; separating the vanadyl chloride and / or vanadium trichloride from the titanium tetrachloride by using the boiling point difference between the vanadyl chloride and / or vanadium trichloride and the titanium tetrachloride, or using the dissolution characteristic of the vanadyl chloride in the titanium tetrachloride; using a gas-solid separation method or a liquid-solid separation filtering method to remove magnesium chloride. The methods provided by the invention have the advantages as follows: vanadium removal efficiency is high, the yield of titanium is high, and the quality of subsequent products such as titanium sponge, titanium dioxide and the like is not influenced. The methods provided by the invention are suitable for being combined with the conventional titanium sponge production technology in the prior art and the titanium tetrachloride refining process in the chloride process titanium dioxide production process.

Description

technical field [0001] The invention provides a method for removing vanadium from titanium tetrachloride, which relates to the field of metallurgy and chemical industry. Background technique [0002] Generally, titanium tetrachloride, as a typical halide of titanium, is an important raw material for the production of titanium industry and is widely used, for example, the main raw material for the preparation of sponge titanium by the magnesium thermal reduction method (kroll method) and the preparation of titanium dioxide by the chloride method are titanium tetrachloride. In titanium metallurgy, titanium tetrachloride is prepared by chlorination roasting method, in which the chlorination agent is chlorine gas. In industrial production, three methods are mainly used to prepare titanium tetrachloride: fluidized chlorination, molten salt chlorination and shaft furnace chlorination. Titanium, because high-titanium chloride slag or rutile is generally used as raw materials for p...

AI Technical Summary

Problems solved by technology

In titanium metallurgy, titanium tetrachloride is prepared by chlorination roasting method, in which the chlorination agent is chlorine gas. In industrial production, three methods are mainly used to prepare titanium tetrachloride: fluidized chlorination, molten salt chlorination and shaft furnace chlorination. Titanium, because high-chloride titanium slag or rutile is generally used as raw materials for production, the produced titanium tetrachloride contains a certain amount of impurity elements such as Al, Fe, V, Mn, Si, etc., which seriously affects the quality of subsequent products

Therefore, some high-boiling and low-boiling impurities can be removed by physical distillation in industrial production, but vanadium in crude titanium tetrachloride is often expressed as VOCl 3 and VCl 4 form, its boiling point and TiCl 4 It is basically equivalent but difficult to remove by rectification, and the cost of freezing and crystallization is high. For this reason, chemical methods are often used to remove vanadium. Copper, aluminum powder, hydrogen sulfide and organic matter are widely used in industry, and carbon and silicic acid are widely used in industry. , silicon powder, lead, zinc, nickel, molten salt, low-valent titanium chloride, but each has its own advantages and disadvantages

[0003] Generally, the vanadium removal method is selected according to the raw material characteristics, cost, and operating conditions of titanium tetrachloride. For example, although the copper wire has a good effect in removing vanadium, it is not suitable for sponges with low vanadium content due to difficulty in recycling copper and vanadium and high labor intensity. Titanium use; aluminum powder removal of vanadium can effectively increase the yield of titanium, but aluminum powder is expensive and subsequent aluminum removal is required to increase costs, so only some sponge titanium companies use it; some sponge titanium factories in the United States and Japan produce hydrogen sulfide at a distance The by-product factory is relatively close, so cheap hydrogen sulfide is used to remove vanadium, but there are disadvantages such as poor working conditions and low yield of titanium tetrachloride; organic vanadium removal has the advantages of convenient operation and good effect, but there are also residues and scarring , Re-distillation and other shortcomings, and the research on this method is not enough in our country, and there are still some problems in the process equipment

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