Sulphuric Acid Resistance for Concrete Walls
An ongoing discussion from 2006 through 2014 and counting . . .(2006)
Q. I want to know what type of coating can be used to protect concrete walls from sulphuric acid. This walls are the containment walls for the sulphuric acid (98%) storage tank. Want to find an alternative to acid resistant brick.Young Kwan
Refinery - Dominican Republic
A. Hi Young,
You didn't mention the tank size nor the temperature.
I don't know of any 'lining' that would do the job.
The alternative is expensive. Use a fluorocarbon ... but how to bond it to the brick? Maybe use, say, PVDF with a fibre backing might, using epoxy, bond to the brick.
But then I ask you about your brick. There are Dolomite type bricks which would be, I think, nbg due to their limestone content.... but aren't there, too, acid resistant bricks?
We, back in the 60's, use to make up Chlorate tanks using PVC which was then fibreglassed ... what one now calls dual laminates. And there is a PVC, a 'red' grade of the German Trovidur which is said to be OK at 96% or was it 98% sulphuric ... at R.T. ! Was it Trovidur NL? I forget.
White Rock, British Columbia, Canada
(It is our sad duty to
advise that Freeman passed away
April 21, 2012. R.I.P. old friend).
A. Hello Young,
I can't see the drama here. My guess is the Sulphuric Acid is at ambient temperature and the storage tank is in a tank farm or similar. The tank is most likely to be made of mild steel and the vent is pointing downwards toward the ground and away from water vapour such as steam or a cooling tower outlet. The reason for the containment is in case of a spill when filling the tank or a leaking connection to the tank.
Generally if there is a leak it is not a catastrophic one, just some drips from a gasket or a couple of liters from a filling hose. In either case it will be noticed at the time of tank filling, or at a routine daily inspection. So I believe you should just stay with the untreated concrete containment and keep a supply of sodium carbonate (soda ash) or sodium bicarbonate (bicarb) close at hand to neutralise any acid spill.
If this is not what you want to do, then make the containment out of mild steel and coat it with some rust preventative paint. If there is an acid spill, clean it up and repaint the affected area.
If that is not on the agenda then make a liner for the containment out of CPVC with suitable pads to support the storage tank.
Basically the containment area is not to store the acid, it is the prevent the spread of the acid in case of a spill. The tank will never burst, just dribble from a pin hole where the acid and water have been in contact. So as long as the leakage is stopped and the lost acid is treated then you are in a win win situation. BUT PLEASE have the tank wall thickness tested at least every 2 years if not sooner, particularly around the inlet, outlet, and vent connections.
Safe acid storage.
- Doncaster East, Victoria, Australia
A. There is not enough information about the operating conditions that the container needs to withstand and speculation about what may or may not be the situation. Furthermore, there is a lot of confusion as to what is meant by epoxy resins - there is a myriad of such materials, all of which have different properties. I know that hot concentrated sulphuric acid has been used to "unpack" integrated circuits that have been sealed in epoxy resins, as discussed by Bruce Hamilton back in 1999. There are also numerous manufacturers of epoxy resin floor products that claim to offer short term protection from 25% sulphuric acid at 20 C. You may want to ask your resin suppliers what they would recommend, so if it goes wrong, you can sue them! However, make sure you get everything in writing with no caveats.
There are other alternatives that MAY do the job, such as PVDF, Teflon or Tefzel. My preferred one would be Teflon (PTFE) but it is expensive and not the easiest of polymers to work with. Not knowing the size, volume and temperature, it is difficult to suggest anything, but you may want to consider glass. There could be problems is applying it however....
R&D practical scientist
Chesham, Bucks, UK
A. Hello all;
I'm not a lining expert but one thing I do know is that the only acid that works amazingly well to strip off rejects from my Epoxy CED painted parts is Sulphuric Acid.
I have used Epoxy based Paints sold as Acid proof paint perform miserably; Marine paints actually work much better for corrosion protection.
Bangalore, Karnataka, India
A. After review of Ashland Chemicals Corrosion resistance guide for their Epoxy Vinyl Ester Resins they do not recommend or have data above 75% concentration of Sulfuric Acid. I would recommend an ECTFE liner to protect the brick that would be mechanically attached then the seams would be welded to assure a leak proof system.Brad Warning
Maple Ridge, British Columbia, Canada
A. We are next month carrying out the coating / dress of a SULFUR pit covering about 1,000 M^2. the pit is used to melt SULFUR grains, process results are SULFUR ACID 100%, warming up to 165 °C, pH from 2 up to 13, 7 Atm. pressure.
We recommend you NOT to use any EP or PU resins for your purposes as the coatings are NOT good for use of SULFURIC acid, you SHOULD use CHEMICAL RESISTANCE REFRACTORIES.
- Beit Hananya, Israel
A. I think you can use a lining of limestone. Not very sure though. Read in some journal. Actually I think it's used as an admixture rather than as an external agent.Ajit Agranayak
- Calicut, Kerala, India
A. Potassium silicate concrete made in the UK has been used successfully for lining sulphur pits in Europe and overseas.Dr JOHN HANCOCK
- workshop nottinghamshire UK
May 13, 2010
A. In our experience , lining a 98% sulphuric acid storage area requires an acid resistant brick / tile lining consisting of a Rhepanol ORG membrane followed by the tile / bricks fully embedded in a phenolic furfural resin mortar. We have been installing these linings for the last 30 years and they have proven to be the best.Scott Sneddon
- Jhb, South Africa
May 17, 2010
Hi. I have to agree with Tony Johnston that there may be too much drama here :-)
Young wants a less expensive coating for the concrete secondary containment walls around his tank, not an acid storage tank, and much of the advice seems centered around exotic and expensive technologies for sulphuric acid storage tanks. Am I reading an implication that some people feel containment areas must be just as capable as the tank itself? Or are they misreading the question?
Further, my understanding of the purpose of acid-proof brick is to reduce the temperature that the liner is exposed to. I would not expect there to be a temperature issue in this case.
Ted Mooney, P.E. RET
Pine Beach, New Jersey
August 24, 2010
A. For this specific application, I suggest acid resistant tile fixed with potassium silicate type acid resistant mortar. The most suitable and economical acid resistant lining. No epoxy/PU resin base system will give you good acid resistance.Raju Joshi
- Ahmedabad, Gujarat, India
October 20, 2014
Recently I have come across a similar requirement and have found BASF has a competent product.
BASF Mastertop 1822 : Phenol Novolac Epoxy Resin coating
(The MSDS / TDS certifies for 98% H2SO4)
Considering the requirement is for Containment tank (NOT storage tank), this system is expected to be compatible.
Another option would be GRP : Vinyl Ester Epoxy Lining
- Kingdom of Bahrain
December 11, 2014
A. Hello Young
Many Chemical Waste Treatment Plants I visit have lined their containment tanks with fibreglass to protect against acid leaks and spills.
This seems to work, and is safe to walk on when the need arises -- I think that resins may also work well but may provide a slippery floor especially in winter weather which is not good if workers have to access the bund for any reason.
Good luck with your quest for a solution.
- CHESTER, Cheshire UK
March 22, 2015
A. We have several tanks in our facility which are 98% sulfuric acid holding tanks used in our processing. We had Sulfulox 765 tank linings from EMP Inc in Syosset NY linings installed in 2005.
We have 7 tanks, 6 at ambient temperatures, one is 150 °F.
Upon inspection in January, the coating is still holding up very well with no signs of wear.
- New York, New York
Ed. note-- Readers: to the extent possible, please suggest types of products rather than offering testimonials to proprietaries -- because experience proves that the minute a sales manager sees their competitor recommended, the race to the bottom is on :-)
September 27, 2016
I need a paint to protect my surface from spray of sulfuric acid.
Please guide me.
- Isfahan, Iran
A. Hi Samaneh. There are supposedly "acid resistant" paints, but I doubt that they will help much. You'll probably need a "coating" (something 30 mils thick) rather than a "paint" (2 mils thick).
You haven't told us what your "surface" is made of, or the strength or temperature of the sulfuric acid. If it's metal, a sprayed or dipped vinyl plastisol coating is probably a possibility. If it's concrete, an epoxy or polyester troweled-on coating would probably be good. Good luck.
Ted Mooney, P.E. RET
Pine Beach, New Jersey
October 5, 2016
A. The best coating for concrete is a multi-layer troweled coating (usually a filled acrylic) that includes a PVDF surfacing veil embedded between coats. This is expensive, but the most durable.Lyle Kirman
Consultant - Cleveland Heights
Are there quality guidelines for tank construction and lining?October 19, 2016
API = American Petroleum Institute
I'm sorry for my terrible English.
I would like to share with you a problem: distortion/ waviness in the bottom of new tanks:
1 - The API 650 [link by ed. to spec at TechStreet] does not specify a tolerance for distortion of the bottom of tanks.
2 - The contractor takes advantage of this situation to not repair the deformity.
3 - The API 653 [link by ed. to spec at TechStreet] specifies the tolerance but for the old tanks and not new tanks.
4 - The bottom of tanks is lined with acid resistant tiles. The lining degrades (cracks, lifting, ...). The cause is distortion of the bottom.
Question : are there API standards for new tanks who specify these tolerances? Can I use to ask contractor to repair or change the bottom?
- Casablanca MAROC