[alt-photo] Re: Don't take the brown FAC!

[Loris Medici]

Peter, this is very interesting. Can you please elaborate? It would be
nice to have a home recipe for making green FAC... How much of each do
you use?

TIA,
Loris.


2010/5/4 Peter Friedrichsen <pfriedrichsen at sympatico.ca>:
> Trevor,
>
> As far as altering it to change it to the green variety, I had no success
> with this by adding additional ammonia and citric acid. It appears that
> above and beyond the ratios of iron, ammonia, and citrate, the way in which
> it is made also affects its final properties. I know this because I make my
> own green variety from scratch.
>
> Essentially it is made by adding ammonia (or use ammonium bicarbonate) and
> citric acid to iron hydroxide ( a messy red mud)  If you add the citric acid
> first,  to make ferric citrate, then add ammonium citrate to make FAC, it
> will make the brown variety. Now, if you add ammonium citrate + citric acid,
> both together to this mud, then the green variety forms. So it seems that as
> the ferric hydroxide dissolves, it must have the ammonia component
> available, or else you will just get the brown variety, and it will stay
> brown even if you attempt to re-balance the ratios.
>
> At least this is my experience.
>
> Peter Friedrichsen