Removal method of low melting point complexes in molten salt chlorination production titanium tetrachloride eluting tower

Abstract

Provided is a method for removing a low-melting-point complex in an elution tower for producing titanium tetrachloride through fused salt chlorination. When titanium tetrachloride is produced by adopting a fused salt chlorination method, high-temperature titanium tetrachloride gas containing chloride impurities and produced by a fused salt chlorination furnace is subjected to dust removal of a dust collector and then enters the elution tower to perform elution by using titanium tetrachloride liquid, a water sprinkling spray head is arranged at the top of the elution tower, the water sprinkling spray head sprinkles water by leading nitrogen, the water entering the elution tower performs hydrolysis reaction with NaAlCl4 and NaFeCl4 low-melting-point complexes entrained in the titanium tetrachloride gas and AlCl3 to generate aluminum oxide and ferric oxide, the oxides enter an elution tank of the elution tower along with the titanium tetrachloride and are mixed in the slurry, and the slurry in the elution tank returns to the dust collector for dust collection. The method has the advantages that the NaAlCl4 and NaFeCl4 low-melting-point complexes in side reaction can be removed, and long-time and stable operation of a fused salt chlorination reactor system is ensured.

Description

technical field [0001] The invention relates to a method for removing low-melting-point complexes in a leaching tower for producing titanium tetrachloride by molten salt chlorination. Background technique [0002] At present, large-scale molten salt chlorination production technology is a mature technology in China, and the alumina component in the titanium-rich material will be chlorinated to form AlCl in the process of carbon chlorination. 3 , The chlorination rate is usually above 50%. AlCl 3 It is a layered structure in the solid state and will convert to Al when it is close to its melting point temperature 2 Cl 6 The molecular structure of the dimer vapor molecules volatilize into the gas phase; when the temperature rises further, the dimer molecules decompose into AlCl 3 molecular. In molten salt chlorination system, FeCl 3 Behavior with AlCl 3 similar. In the molten salt chlorination reactor, the product AlCl 3 , FeCl 3 It may form a chloride complex NaAlCl ...

AI Technical Summary

Problems solved by technology

Since the crude titanium tetrachloride underflow slurry produced by leaching in the leaching tower is directly returned to the dust collection or chlorination system, it will be gasified again, thereby continuously circulating and accumulating in the chlorination-dust collection-leaching system, which not only increases It will also easily cause problems such as system wall formation, partial liquefaction of dust collection slag, and fouling of heat exchangers, which will affect the continuity and stability of chlorination operation.

In addition, NaAlCl 4 , NaFeCl 4 and a small amount of AlCl 3 It will also affect the follow-up TiCl 4 Refining and production of sponge titanium have adverse effects, and as a very acidic Lewis acid, it is highly corrosive to steel equipment

It has caused great difficulties in the cycle of stable production of titanium tetrachloride products