Compilation of discussions on sulfuric acid at various concentrations
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75–80% waste sulfuric acid, containing impurities such as elemental sulfur, phosphorus, sulfurous acid, phosphoric acid, and dissolved acetylene. It is hoped to concentrate it to over 95% – where can one find such technology, equipment, or operating systems? I would appreciate your advice. This post was last edited by lengyue26 on 2007-7-5 09:28.]
It depends on the volume you need to produce; theoretically, the pot concentration process can achieve a concentration of over 98%； Vacuum concentration can generally achieve a concentration of 93%. For general yields of tens of thousands of tons, vacuum concentration can be used; otherwise, pot concentration is employed.
The production volume will be 15,000 tons at the initial stage, with a target of 40,000 tons in the end. Are there any suppliers of relevant technologies and devices available?
If elemental sulfur and phosphoric acid cannot be separated from sulfuric acid, concentration is impossible; therefore, I would like to ask if there are any separation methods.
The acid used to adjust the pH value in our wastewater treatment system is sulfuric acid with a concentration of around 68%. The pipes currently in use have a diameter of DN15 and are made of 304 material; this material is likely not resistant to the corrosion caused by 68% sulfuric acid. I would like to ask what type of material would be more suitable for such pipes? 316 should also not work; the metering pump manufacturer said that Hastelloy materials would suffice. I don’t have any experience in this area, so I’m seeking advice from everyone! ! ! This post was last edited by lengyue26 on 2007-6-12 19:00]
Polyethylene pipes work well, especially for dilute acids; we use this type of pipe here
PP pipes (polypropylene) can also be used!
Since the concentration of your dilute sulfuric acid is still relatively high, 316 stainless steel pipes will suffice; polytetrafluoroethylene pipes can also be used. They are all relatively safe.
Using GRPP pipes is quite convenient and the cost is relatively low.
Thank you for all your suggestions. Using polyethylene or polypropylene pipes results in thinner pipes; firstly, their strength is lower compared to steel pipes, so whether additional protection is needed in areas where they are prone to being damaged； Secondly, I personally feel that this material tends to age easily; is external anti-corrosion treatment necessary? I appreciate your advice! If 316 really works, it would be much easier! But the pump pre-filter 316 mesh has been almost completely corroded!
Covering the polyethylene pipes with seamless steel pipes can ensure strength. Aging is a problem; the pipes need to be replaced every six months or a year, which is somewhat troublesome, but the cost is relatively low. Titanium alloy could be used for the filters, and that should work.