Vicente-M. Vizcay Castro (mapa@bitmailer.net)
Tue, 05 Oct 1999 08:43:46 +0200
Dear Judy:
A comments:
1: I suggest to you that you read slowly and with more attention the
procedure.
2: Not criticize, suggest improvements.
>The process requires the evaporation and absorption
3: (first: pouring of; second: absortion; third: evaporation,
fourth: drying by agent)
>of 116.9 gms of nitric acid.
4: Specific gravity of 54% (w) nitric acid solution: 1,34 g/ml
116.9 g (HNO3) + 100,3 g (H2O) = 162 ml
a) Pouring of ......... 17 ml
b) Absortion ......... 100 ml
c) Evaporation ......... 25 ml => 18g of HNO3
d) Drying .......... 20 ml
>This must be dried in the dark. There is no safe way to accomplish
>this for the typical alt photo practitioner.
4: You don't have any place in which you could put a closed hermetic
container ?
I'm sorry.
> The same issues as making aqua regia, except that the fumes are
encouraged.
5: I supose that in making Aqua Regia (because it has HCl, HNO3, Cl2, NOCl,
NO2, NO,
N2O4)
Nitric acid has HNO3, but less
NO2, NO and N2O4.
All these free.
> Also, soaking up the acid in paper towels is not a great idea.
6: That another compatible option so cheap or more than the previous one
proposes you?
>Read section 7 - this decanting takes 340 hours (with acid fumes present),
>but maybe 10-100 times longer.
DON'T FORGET THAT THE BEAKER IS ALWAYS, EXCEPT FOR BRIEF MINUTES, COVERED
(hermetic covered) BY A PIECE OF PLASTIC PLASTIC.
> A centrifuge can help.
7: A centrifuge,...., a vacuum filtration system, ......, a chemical
hood, ...a....
A well equiped chemical laborathory ... IS BETTER.
> I can just imagine this beaker of nitric acid being flung around in a
darkroom.
8: Very good imagination.
>This procedure is referenced in Dick Stevens book.
9: In Dick Stevens book:
"Method 7.: Ferric nitrate plus oxalic acid dissolved in nitric
acid produces ferric oxalate."
The procedure isn't in Dick Stevens book because the procedure does not
dissolve the oxalic acid in nitric acid.
> It's one of the procedures he does *not* recommend - the others are safer
and easier.
10: Mr. Stevens words are:
" These three methods (Oxidation of the FeC2O4 (2 methods) and
fresh
Fe(OH)3 plus oxalic acid) have more advantages and fewer
drawbacks than
the other four. They are simpler, safer, cheaper, and quicker,
and they
produce a cleaner, less contaminated product"
It's Mr. Stevens opinion (opinion that I don't share).
I suggest you that:
- YOU follows to the letter the procedure,
- YOU obtains your own powder oxalate,
- YOU test it
AND YOU forge your own opinion at that moment.
>It also will not produce as good of a grade of FO as the other Stevens
>process. Even the RS procedure (free, on the B&S website, no password) is
>safer, easier, and will produce a more pure FO. Much more pure.
When you said "more pure", have you analysis of both products?
If not, you can not say that that it has not demonstrated
READ HE PROCEDURE WITH ATTENTION:
The grade of FO obtained is similar to the grade of reagents
used.
PLEASE, FOR ALL: there is to be moderated in comments, constructive
and to try not to hurt the semsibility of others people.
Jeffrey and me alone we want to contribute to the knowledge of
other people and this always without any type of hidden interest.
Regards,
V. Vizcay
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