Making Ferric Chloride

[ozfish]

I have a water filtration plant with the primary purpose of removing 50ppm of Fe2+ from ground water. We utiliswe approx
10000-200000 litres per day

I am looking for a use of the waste product and was considering Ferric chloride, and was curious as to how it is made - as maybe we could alter the process to achieve both the removal from the ground water and produce a by product for other purposes.

Regards

 

[moltenmetal]

Presume you're oxidizing the Fe+2, preciptitating, thickening and filtering. Your cake will be loaded with other stuff (manganese, flocculant polymer etc.) which will probably render the product unsuitable for other uses.

Does your facility have a use for the ferric chloride, or are you intending to sell it? If it's the latter, forget about it. It's too easy to make ferric chloride from old Camaros and hydrochloric acid to bother using your filter cake...

Is the 10k-200k litres the amount of water you're processing? If so, your 50 ppm Fe+2 doesn't amount to much.

 

[ozfish]

Thanks for the reply moltenmetal!
The 100k to 200k litres should equal 5-10kg of per day

We are purely oxidising and filtering - not other chems going in.

I would like to use the FeCl it in our waste water stream.

 

[moltenmetal]

Is diverting 5-10 kg/day of a low-value, non-hazardous waste really enough for you to be thinking about this? The material you're replacing, FeCl3, is as cheap as dirt. Unless you've got people lazing around looking for things to do... Then, you'll be looking for a plastic tank, a plastic- or FRP-coated agitator, and a drum of hydrochloric acid. You should be able to redissolve the Fe(O)OH by taking the pH below 3 with HCl, but again I doubt it's worth the labour and hazard. Test on a small quantity in the lab first- you may need excess acid, or to heat the solution. Excess acid will probably wipe away any savings in your wastewater plant by requiring more base addition for neutralization.

 

[ozfish]

Hi Moltenmetal
To disolve with HCL would be a waste of time, however I was thinking that I might use Chlorine to precipitate the iron out of solution in the treatment plant rather than using oxygen.

The use of chlorine may assist the quality of our treated water.

Do you believe that may work

 

[moltenmetal]

Use chlorine if you like, but that won't precipitate ferric chloride. If the pH is above 3, you'll still precipitate the ferric oxyhydroxide "floc", regardless what oxidant you use. As to chlorine improving the quality of your treated water, that depends entirely on what else is in it. You said before it was pretty much just water with 50 ppm of Fe+2 in it...