75% of sulfuric acid storage tank material selection issues
Thread Content
What are the differences in the selection of materials for storage tanks containing 75% sulfuric acid at normal temperature and pressure and 75% sulfuric acid at 100°C: Can Q235-A be used?
It definitely can’t be used. Use ceramics.
Can use enamel or glass lining
75% sulfuric acid cannot be used with A235-A! Use CR alloy materials or use graphite or ceramics. It is rarely stored at 75% concentration. It is generally stored at 98% and diluted to 75% during use. For reference.
1. Contains 75% sulfuric acid at room temperature and pressure: It is recommended to use polyethylene, polyvinyl chloride, polypropylene and other plastic or glass fiber reinforced plastic (glass fiber reinforced plastic) containers. 2. Contains 75% sulfuric acid at 100℃: It is recommended to use glass-lined containers
75% sulfuric acid, at 100 degrees Celsius, in addition to ceramics, enamel, and glass, high silicon cast iron and tin can also be used. There are more materials available at room temperature, but Q235 is definitely not possible.
If you consider long-term life, you can consider using B2 alloy. It can be used in sulfuric acid with any concentration below 100 degrees.
It is okay to use carbon steel tanks at room temperature. I checked and found that it can be used at least 70%. The passivation film will not be destroyed, but it cannot be stored for too long because concentrated sulfuric acid will absorb water in the air. Once it is lower than 70%, it will corrode the equipment.
75% sulfuric acid, if the storage tank is lined with ceramic or enamel at 100 degrees Celsius, Q235 will definitely not work.
If it's fuming sulfuric acid, it's OK, but it's also related to temperature. Dilute sulfuric acid is definitely not possible. It can be lined with ceramics or enamel or lead plates. :loveliness:
Graphite lining can be considered for 75% of sulfuric acid storage tanks
You can consider using fiberglass, but only at low pressure.
Either pp or PE is acceptable
Check the corrosion data sheet and you can find all commonly used media.
It is also a good idea to use enamel and acid-resistant ceramic tiles for 100-degree 75% sulfuric acid.
Q235 definitely cannot be used. Use an enamel kettle or lined fluoroplastic. Another way is to use Q235 to coat the inside with anti-corrosion paint. Many acid pipelines do this.
This problem can be solved, because sulfuric acid is a dividing line at 70%, which is very stable from about 70% to 102%. The corrosion degree will intensify again between 102---1-5%, so as long as the sulfuric acid concentration is not less than 70%, you can use carbon steel tanks, but you must prepare a tank plan, especially now that some tanks have higher requirements in this regard. Of course, the ones mentioned by the poster can also be made of other materials, but the cost will go up.