How to remove excess iron in PAA tank

[KirbyWan]

Howdy all,

Over the weekend we had a heater line burst in our phosphoric acid anodize (PAA) tank which dumped iron rich water from our hot water system into our PAA tank. Is anyone familiar with a method to remove the iron so we can avoid recharging the tank from scratch? Any suggestions pointing me to more information is welcome. I think this may be more appropriate for one of the chemical engineering/chemistry forums, but since this process is for aircraft structures (BAC5555) I thought I should throw it out here first. the tank has phosphoric acid with sodium dichromate.

Thanks,

-Kirby

Kirby Wilkerson

Remember, first define the problem, then solve it.

 

[berkshire]

Depending on the percentage of dissolved iron in the water, it should convert, to iron phosphate, when it meets the phosphoric acid, and precipitate out of solution. It should therefore end up as sludge on the bottom of your tank.
B.E.

 

[rb1957]

how about the dilution due to the added water ? i guess you just add conc. phosphoric acid to adjust the pH ?

 

[KirbyWan]

*sigh*, Sorry folks, but I gave bad information. I confused a couple of tanks. It is the sulfuric acid/sodium dichromate tank that had the leak this weekend. Sulfuric acid 38.5 to 41.5 ounces/gallon with sodium dichromate 4.1 to 12 ounces/gallon. We have 3500 ppm iron. BAC5555 indicates a maximum of 180 ppm. Each tank is about 3800 gallons.

Sorry for asking the wrong question.

-Kirby

Kirby Wilkerson

Remember, first define the problem, then solve it.

 

[berkshire]

Kirby,
Try talking to these people
:

http://www.dow.com/liquidseps/prod/sp_acid.htm

They make resin beads for removing contamination from acid tanks.
B.E.