Cast Iron in a citric acid environment

Question

Cast Iron in a citric acid environment

jasonreber (Mechanical)

(OP)

10 Jul 03 16:36

I am designing a pump station that includes a cast iron submersible pump. The pumping medium is water that includes pineapple juice. I am concerned about corrosion, and am considering using zinc anodes to help combat the corrosion. Will this work?

Thank you for your replies,
Jason Reber,
Honolulu, Hawaii

negotiator (Electrical) · Answer 1 · 2003-07-15 17:44:50

They will get their zinc for the day (week). I use stainless (medical grade), so the obvious repurcussions do
not occur (chemical-leeching OR legal).
thestocksguy@hotmail.com

jasonreber (Mechanical) · Answer 2 · 2003-07-15 17:59:49

This pump is being placed in wastewater. No need to worry about contamination. Would contamination be slowed if the pump is continually submersed (no exposure to air)? Are the anodes going to dissolve rapidly (how fast compared to seawater)?

Thanks for any help you can provide.

jasonreber (Mechanical) · Answer 3 · 2003-07-15 21:47:34

In the above message I meant to ask if corrosion would be slowed (not contamination).

Sorry for the mistake.

pik199 (Materials) · Answer 4 · 2003-08-07 19:25:57

Hi,

Your corrosion will be slow down.
Your wastewater will be contaminated by zinc, and you need clean it.
What do you need more?

Aleksandr

JimMetalsCeramics (Materials) · Answer 5 · 2003-08-07 20:11:14

RE: Cast Iron in a citric acid environment

JimMetalsCeramics (Materials) 7 Aug 03 20:11

What is the pH of the wastewater?

jasonreber (Mechanical) · Answer 6 · 2003-08-07 20:14:21

I am estimating a minimum of 4.5, this water is only washing off the pineapples

JimMetalsCeramics (Materials) · Answer 7 · 2003-08-07 20:36:22

I would not expect the cast iron to appreciably etch at that pH. You can use sacrificial coatings (e. g., Zn) but they might only slowly etch preferentially.

Charh (Materials) · Answer 8 · 2003-08-11 19:39:57

We have had really good luck with using a high chome white iron ASTM A 532. It has good corrosion resistance and wears much longer than the regular ductile or grey iron.
Let me know if you need any additional info.

rmasline (Chemical) · Answer 9 · 2003-09-08 13:35:53

Just out of curiosity, why don't you consider using a different media for your pump? There are many economical choices for pumps that could probably suit your needs and would be resistant to the specific corrosion problem you are trying to combat.

Does the pump have to be submerged or totally surrounded by the fluid? By using a non-submerged pump you could control what parts where wetted and insure that the seals and gaskets (contact points) were non-reactive with your solution.

Just my two cents.. good luck with your project!

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Cast Iron in a citric acid environment