Can carbon steel be used for 92.5% concentrated sulfuric acid storage tanks?
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For a sulfuric acid storage tank with a concentration of 92.5%, a volume of 1000 cubic meters, and a storage temperature of 40°C, can it be made of carbon steel? Is internal anti-corrosion treatment necessary? What type of internal anti-corrosion treatment should be used? Those who have experience with such storage tanks, please offer some guidance
I checked the \"Corrosion Data and Material Selection Manual\" (edited by Zuo Jingyi and Zuo Yu – 1995 edition): For carbon steel, at a sulfuric acid concentration of 75–100%, performance is good at 25°C, with an annual corrosion allowance of 0.05–0.5 mm； At 50°C, it is usable but suffers from severe corrosion, with an annual corrosion allowance of 0.5–1.5 mm.
Just a DN3600 acid tank with 93% acidity that had been in use for two years was taken down, with the temperature around 40°C as well. It was originally expected that one year would be sufficient, but two years later it was still in good condition.
Are there any requirements regarding the height and pressure of the storage tank? If the requirements for height and pressure are not high, fiberglass can be used
The storage temperature is 40°C; it can be made of carbon steel, and no internal anti-corrosion treatment is required. Use it with confidence.
No anti-corrosion treatment is needed inside; it’s sufficient to ensure the quality of the welds during welding and to reinforce the pipe ends. The outer surface requires anti-corrosion protection, while the main parts that are subject to wear inside are likely to be located at the liquid level. It generally works fine for 3 to 5 years, provided that the foundation is solid, the design is defect-free, and the construction quality is guaranteed. After 3 to 5 years, with some repairs, it can be used for a few more years.
If it can be ensured that the sulfuric acid concentration remains above 90%, any iron container will do.
For a sulfuric acid tank with a capacity of 1,000 cubic meters, strength is the primary consideration; since sulfuric acid has a high density, carbon steel is an appropriate material. If a container has a lifespan of only two or three years, the storage cost is too high.
Carbon steel is a viable option, but its lifespan is likely only 3 to 5 years; consider the costs before deciding on which type of tank to use!
There’s no problem at all; a passivation film will form. However, the flange joint needs to be lined with plastic