Application of industrial pure titanium in chemical industry
Titanium metal has excellent corrosion resistance and mechanical properties, is widely used in many departments. Especially in chemical applications, titanium can replace stainless steel as a corrosion resistant material, which has a very important significance in extending the service life of equipment, reducing costs, preventing pollution and improving productivity. In recent years, the scope of titanium used in chemical industry in China is constantly expanding, the amount of titanium is increasing year by year, titanium has become one of the main anti-corrosion materials in chemical equipment. Titanium, as a kind of corrosion-resistant structural material used in chemical equipment, has become an ideal material in chemical equipment.
Chlor-alkali industry is an important basic raw material industry, its production and development have a great impact on the national economy. This is because titanium has better corrosion resistance to chloride ions than commonly used stainless steel and other non-ferrous metals. At present, titanium is widely used in the chlor-alkali industry to manufacture metal anode electrolytic cell, ion membrane electrolytic cell, wet chlorine cooler, refined brine preheater, dechlorination tower, chlorine cooling washing tower and so on. In the past, non-metallic materials (such as graphite and polyvinyl chloride) were mostly used for the main parts of these equipment. Due to the unsatisfactory mechanical properties, thermal stability and processing performance of non-metallic materials, the equipment was bulky, consuming large energy and having short service life, and affected product quality and polluted the environment. Therefore, since the 1970s, metal anode and ion membrane electrolytes have been used to replace graphite electrolytes, and titanium wet chlorine cooler has been used to replace graphite cooler, and good results have been achieved.
For example: the application of titanium wet chlorine cooler. Salt electrolysis production of caustic soda is to produce a large amount of high temperature wet chlorine gas, the temperature is generally 75~95℃, need to be cooled and dried before use. The production of chlorine gas from salt electrolysis in China has affected the output and quality of chlorine gas in the past because of unreasonable cooling process or corrosion of cooling equipment, and seriously polluted the environment. Titanium coolers resistant to high temperature wet chlorine corrosion were put into production, which changed the production face of chlorine in chlor-alkali industry. Titanium is very resistant to corrosion in the environment of high temperature and wet chlorine. The corrosion rate of titanium in chlorine water at room temperature is 0.000565mm/a. In chlorine water at 80℃, the corrosion rate of titanium is 0.00431mm/a. In 95% wet chlorine, the corrosion rate of titanium at room temperature is 0.00096mm/a. Many chlor-alkali coolers, often made of titanium wet chlorine, have been in use for nearly 20 years and are still in good condition.