At present, the mainstream production processes of titanium tetrachloride mainly include boiling chlorination and molten salt chlorination. Among them, the molten salt chlorination method is mainly used in Kazakhstan, Ukraine and other countries because of its higher quality requirements for titanium-rich materials than boiling oxidation. In order to maximize the value of titanium ore resources, some enterprises in the country also adopt the method of molten salt chlorination; the boiling chlorination method has higher requirements on raw materials and is mainly used in developed countries such as the United States and Japan. The boiling chlorination process started from the Φ450mm small test furnace in the 1970s, and has experienced Φ600mm, Φ1200mm, and Φ2400mm industrial furnaces respectively. At present, a large-scale boiling chlorination furnace with a diameter of 7 meters has been built and put into industrial production.
Titanium-rich materials (high-titanium slag or rutile, or a mixture of the two), petroleum coke and sodium chloride from the mixing and preparing process of industrial chemicals are uniformly mixed in an optimal ratio, and then continuously fed through a screw feeder and a fuller pump. Add the chlorination furnace from the side, react with the chlorine gas and other gases entering from the other side of the boiling chlorination furnace at a furnace temperature of 700-800 ° C to generate a mixed gas containing TiCl4, and the mixed gas enters the quenching tower on the top of the chlorination furnace, where In the quench tower, crude TiCl4 is sprayed into the mixed gas to cool the TiCl4 gas, so that the gas temperature is cooled from about 500 to 700 ° C to nearly 100 to 380 ° C, keeping TiCl4, SiCl4 and VOCl3 gaseous, and the rest of the metal chlorides become solid.
After quenching, the chlorinated gas containing SiO2, petroleum coke, TiO2 and metal chloride solids enters the cyclone dust collector, and the cyclone separates the solid vanadium slag, calcium chloride, magnesium chloride, iron chloride. When the solid material enters the solid slag treatment process, the TiCl4 gas separated by dust collection enters the condenser, and the condensation work is completed through secondary condensation (direct condensation and indirect condensation). The liquid crude TiCl4 is rinsed, and the dust is washed down into the liquid TiCl4, and then passes through an indirect condenser to recover about 10% of the TiCl4 entrained in the gas. During the condensation process, the liquid titanium tetrachloride liquid enters the titanium tetrachloride storage tank, and the uncondensed gas needs to be further processed.
In the production process of titanium tetrachloride, some chlorinated waste gas will inevitably be produced, and the national environmental protection policy is becoming more and more tightened, and the pressure on enterprises is also increasing, but through the innovative research and continuous testing of a large number of technical experts. The treatment technology of chlorinated waste gas is also becoming more and more advanced. While many treatment processes meet technical requirements, they can also create certain economic benefits through resource recycling and other methods, helping enterprises to achieve a win-win situation in environmental protection and economic benefits, and promoting the sustainable development of the national titanium industry.
