What material is better for soda ash dissolving tank and pipeline transportation?

It depends on the temperature. It’s okay if the temperature is not too high

Material selection for lye equipment pipelines: • When the liquid alkali concentration is ≤32wt% and the working temperature is ≤40℃, Q235-B should be selected. • If the liquid alkali concentration is >32~≤50wt% and the working temperature is ≤40℃, 304 or 304/16MnR (composite board) or 316 should be used. • If the liquid alkali concentration is >32~≤50wt% and the working temperature is >40~≤87℃, 316 or 316L should be selected. • For liquid alkali concentration >50wt% and working temperature >87~≤200℃, Ni/20R or Q235-B (composite board) should be used ； For operating temperatures >200°C, Ni or nickel-based alloy should be used. In addition to the above, there are also carbon steel enamel or fiberglass. You can also refer to "6. 1. 2 2 Na OH solution stress corrosion steel" in "SH3059-2001 General Rules for Selection of Petrochemical Pipeline Design Equipment" should be selected according to Appendix D. ”

We have two kinds of lye here, 40% ionic alkali, the temperature is around 40 degrees, the other is 20% lye, the temperature is normal temperature, all pipelines and equipment are made of 316 stainless steel

I would like to ask: In the reactor, liquid alkali (NaOH) reacts with aluminum hydroxide. The concentration of liquid alkali is 30--35%, and the reaction temperature is 120 degrees. What material is used for the reactor? Thank you!

Boss, what people are asking about is soda ash, not caustic soda. Since soda ash contains a small amount of Cl-, the alkalinity of the alkali solution is also strengthened at high temperatures, which intensifies the corrosion of equipment and pipelines. It is of course best to use stainless steel, but the added value of soda ash downstream products is not high (of course, it can also be used for other purposes). All stainless steel tofu has become the price of meat. The key is what the quality requirements are for the product. If the vulcanization is done well, it is not impossible to use carbon steel equipment and pipelines. Our company has a baking soda device attached to a soda ash plant. It uses high temperature (95~99℃) to dissolve soda ash as the raw material for baking soda. All the baking soda devices use carbon steel equipment, and only a few pipes use stainless steel pipes. There is no problem with product quality, and it is also * * The only Silver Award for Baking Soda. Of course, if you produce soda ash downstream products with higher quality requirements (such as pharmaceutical grade baking soda), it is best to use stainless steel.

Those people didn't distinguish between soda ash and caustic soda. What LZ said was soda ash, and they answered caustic soda. The soda ash industry uses very few stainless steel equipment and pipes. Large equipment such as carbonization towers and ammonia steaming towers are generally made of cast iron, and calcining furnaces are made of steel. Anti-corrosion mainly uses alkali sulfide. 7#lfbxsd

Soda ash is far less sensitive to temperature than caustic soda, and the steel used does not need to be too high-end.

Please refer to "Alkaline Corrosion and Protection Technology" Chen Hesheng (China Shenma Group Nylon 66 Salt Co., Ltd., Pingdingshan 467013, Henan)

Just use Q235 for soda ash.