Corrosion protection treatment under [280–300°C & dilute sulfuric acid] conditions
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Ladies and gentlemen, my reaction process is as follows: 1. A certain material is mixed with 98% concentrated sulfuric acid; while stirring, the temperature is increased, and then the sulfuric acid gradually reacts and gets consumed； 2. 1 mole of water is produced without the consumption of 1 mole of sulfuric acid. 3. Upon reaching the reaction endpoint, the temperature of the material system rises to 280–300 degrees, and the concentration of excess sulfuric acid becomes 30%–70%. Under the aforementioned operating conditions – 280~300 degrees Celsius and a final sulfuric acid concentration of 30%~70% – what material should be used for the parts in contact with the material? Or should carbon steel be used, with a certain acid-resistant material sprayed on its surface? Thank you so much!
904L super stainless steel and Hastelloy should both be suitable; however, the price might be unacceptably high. A carbon steel lining works well at low temperatures, while PE, PTFE, and PVC are likely not suitable under such conditions. A ceramic lining should work fine. Cheaper enamel-lined reactors might also suffice
At this temperature, lining with plastic is definitely not an option; it is recommended to use cast iron, enamel, lead lining, titanium, tantalum, or C276. It’s not clear whether tetrafluorographite would work in this situation.
Unfortunately, this is a special-shaped mixer, and it’s very difficult to process. Thanks for the advice!
Well, I’ll check carefully the materials you mentioned. Also ask about the price; P
Hastelloy is likely to be quite expensive; lining with plastic isn’t an option. As for ceramic lining, it depends on the pressure level – titanium material could be a consideration
Can titanium withstand sulfuric acid at high temperatures? I’ll check it.
Titanium cannot be used; you need 30%-70% sulfuric acid. 40% sulfuric acid causes the fastest corrosion of titanium, and the reaction proceeds more easily at higher temperatures
Can Hastelloy withstand it? I feel a bit worried
Hastelloy should be fine; if you’re not sure, you can consult the manufacturer
For metals, tungsten and zirconium should work