What ferrous material is fully resistant to hydrochloric acid?

A. Hi, Mazhar. You can probably rule out all of the common grades of stainless steel. But I think you will have to describe the concentration, the trace contaminants like copper, and the temperature and exposure conditions before an actual material selection can be made. Good luck.

A. Hi Mazhar Ahmed,

The best metal would be Hastelloy-B, having a corrosion rate of <0.02 inches/year according to Chemical Engineers Handbook [adv: suggestions on Amazon, AbeBooks, or eBay] ; Properties of Materials, Table:23-4.

Your next best material would be a polyester or polyethylene tank supported externally with a steel structure which you would coat with a thick epoxy paint.

Good luck,

Thanks Bob. Mazhar should note, however, that Hastelloy-B has only 2% Fe so it's not really a ferrous alloy. He may be looking for a construction material for a tank, but might not be.

Luck & Regards,

A. Hi Amit.
Hastelloy-B might work but probably costs more than a glass-lined vessel. Unfortunately, HCl at 90°C is both very corrosive to all relatively affordable metals, and too hot for most inexpensive plastic construction materials.

Luck & Regards,

A. Hugh !

Well, there are not many metals that will stand HCl over a short or a long time including 316 ss. Maybe Hastelloy C, Carpenter 20 and Titanium ... that's if you've got lots of $$$ ... which you must have if you don't want an alternative.

There is a simpler solution, a very low cost idea. That is to use plastics ... and most plastics should take that low temperature HCl till the cows come home.

Use PVC, ABS, PP, PE ... and for more $$$, use CPVC, PVDF and the weldable fluorocarbons... even fiberglass (but don't use boat resins!).

The other side of the coin is that I'd assume your 'gas' will contain some moisture ... and if you exhausting that to atmosphere you'll not only have a corrosion problem, but ah, you may have to 'scrub' the fumes! And if that is necessary, oh dear, you'll need a fan and some sort of scrubbing arrangement. And even if your HCl gas doesn't contain any moisture, it sure WILL when it hits the outside air.

Cheers !

A. Hi Hugh,
For your HCl fume resistant material, you can choose Hastelloy with PTFE coating. Since operating temperature is 65 °C this coating may resist long. You can also try fiberglass lining, but porosity is to be controlled.
Teflon is also a good solution but rigidity is to be seen.
Best may be the first option.
Sundar

Thanks, readers. Some good answers are doubtless being offered on this page, but I think there is room for somewhat less abstract questions.

When the proposed answers range from dirt cheap polyethylene to outrageously expensive teflon-coated Hastelloy-B the questions are probably a bit too vague :-)

Luck & Regards,

A. Hi Anthony,

A conductive plastic? Well, I guess that they might exist and recall the 'tanker' companies back in ye olden days oxidizing some plastic cladding to make it conductive in order to safely ground a load.

I've got but one idea. That's to use Carbon Fibre ... I've never used the stuff, nor seen it, for that matter. You will know that a matrix of that and an epoxy or polyester gives an enormously strong structure (satellite components, racing car bodies, hi tech hockey sticks, golf clubs, fishing rods, etc.).

But it's CARBON fibre ... and surely carbon must be conductive.

Hence, if you had your tank made out of (FRP) fiberglass and could line the 'inside' with some exposed carbon fibre, that should work but would not if the C.F. were fully resin coated,

Solution: Get a FRP tank made with a coarse and unfinished interior (in order to get a good bond to which you won't get if it's a good and shiny resin rich surface). Obtain the coarsest carbon fibre you can buy, ideally woven roving. 'Glue' that carefully to the inside using resin BUT don't fully coat that material, leave the 'outside', so-to-speak, uncoated so that exposed C.F. is showing. Now you should have a 100% conductive surface.

That's the best I can do to help you. I hope it works.

Cheers !

A. Hi Ikram.
UHMWPE is often specified for good abrasion and chemical resistance, and tanks can be built from it (although you'll need to look into the fabrication methods & details). The agitator blades might be made of Hastelloy-B or tantalum. The agitator shaft can probably remain rubber-lined, or be teflon lined.

Luck & Regards,

A. Hi, Franswa.

I have seen teflon "pan liners" that might serve your needs, and they're quite cheap :-)

Regards,

A. Hi Tauseef. Why not Teflon or similar lining material?

If PTFE linings won't do, please investigate Tantaline or a similar coating/cladding process, as only tantalum and the precious metals are more resistant to HCl than Hastelloy to my knowledge. Tantalum coated stainless steel is reportedly significantly less expensive than Hastelloy.

Regards,

A. Gold.

A. Gold, Platinum and other precious metals meet your requirement.

A. As one should always assume, responses here should not be assumed to be consulting responses that assume any responsibility for outcomes.

Virtually all metals and alloys of metals conduct electricity. The next question is, How well do you need it to conduct?

As far as being resistant to hydrochloric, up to 200 °C, I don't have any references that cover metals in HCl beyond its boiling point. The boiling point varies with concentration but peaks at ~230 °F or ~110 °C. If the boiling point is satisfactory, then an older volume of "Corrosion Engineering" by Fontana and Greene ⇨
shows that Chlorimet 2, Tantalum, Hastelloy B (if the solution is free of chlorine), Zirconium, Silver, Platinum, and a grade of material called Impervious graphite, will all contain this acid from room temperature and low concentration up to 40% and boiling. Out of these, silver is by far the best electrical conductor.

Pfaudler 53 glass (presumably non-conductive) is shown as resistant at higher temperatures, where it would need to be under pressure.

Impurities, or aeration of the acid, may affect the resistance of its container to attack.

I would recommend retaining an expert in your locality to deal with this hazardous material.

A. Tantalum is compatible with concentrated (38%) hydrochloric acid to 200 °C according to compatibility guides. Its conductivity is about 1/5 that of gold but slightly higher than that of Pt.

A. I think that Titanium metal is suitable and cheap& will fulfill your requirement. For which process do you want?, please explain clearly.

For that quantity I would use standard laboratory glassware.
5 Litres is a common size
A quick web search of laboratory suppliers Equador offered several options

A. If you can buy sulfuric acid, why not buy HCl. It would probably end up cheaper and would not be the problem with the Haz wastes.
HCl is available in glass up to 2.5 L and in plastic from 5 gal to 55 gal.
Pool acid is weaker but should be more readily available.

A. Hi Camila,

One of the high corrosion resistant alloys, such as Inconel will probably be your best choice over a typical stainless alloy. Having anything fabricated from Inconel will be the difficult and expensive part.

A. You might want to evaluate Hastelloy C, or possibly monel.

A. Glass and enameled steel can withstand the hydrochloric acid.
Good luck

A. Hi Ahmad
There are usually many other factors in selecting a material but we do not know your detailed application.
If you must use metal, I would consider Monel, Hastelloy or Incolloy. All are expensive and may be difficult to obtain.
Have you considered lining the reactor with PTFE?
As an old chemist, my first choice would be glass readily available as components for almost any reactor configuration.

Hi Ahmad
I do not know if you can get them locally but PTFE lined fittings are readily available.
Search on "PTFE valves"
The specialist suppliers can advise on the most suitable lining and probably design the complete reactor for you using standard parts.

A. Manjunath,
I afraid you cannot find a reasonable Metal for such application. Gold, Platinum...?
Try to change the item (and change the item design) to plastic: Polyethylene, Polypropylene, PVDF, Teflon.