Re: Ferrous to Ferric Oxalate [was Re: patents]

From: Alberto Novo ^lt;alt-list@albertonovo.it>
Date: 02/16/06-04:44:22 AM Z
Message-id: <20060216104423.31267.qmail@webmaild.fe1.aruba.it>

I don't know which is better:
Curtin used a stoichiometric reaction, where you need to know the actual
H2O2 conc.; less H2O2 results in less Fe(III)Ox and some free oxalic acid.
Fe(II) oxalate is virtually insoluble.
Vichy method (direct reaction between ferric nitrate and oxalic acid) leads
to free nitric acid, not easy to handle at home.
A third method is probabily better, but I do not recommend unless you have a
fume hood. From Gmelin (the chemists' Bible): ferric nitrate in conc. nitric
acid plus oxalic acid, filter and leave the solution concentrating over
sulphuric acid. After a day, separate the crystals and wash them with iced
water.

Alberto

> I seem to have tried it an a distant past, and I was not happy with the
> procedure, it took an awfull lot of peroxide to kick the ferrous to the
> ferric (probably because hydrogen peroxide isn't very stable, the conc.
> Goes down with time). You're much better of trying the method by Vichy
> (sp?) as described on Jeff Mathias his excellent web side,
>
> Cor
>
>> -----Original Message-----
>> From: Michael Koch-Schulte [mailto:mkochsch@shaw.ca]
>> Sent: woensdag 15 februari 2006 16:51
>> To: alt-photo-process-l@sask.usask.ca
>> Subject: Ferrous to Ferric Oxalate [was Re: patents]
>>
>> Thanks got it now.
>> It's interesting that the Curtin method doesn't seem to be commonly
>> mentioned as a method for producing Ferric Oxalate for alt.
>>
>> The Curtin method, in a nutshell:
>>
>> 360 parts per weight of ferrous oxalate hexahydrate
>> 126 parts per weight of oxalic acid dihydrate, suspended continuously
> in,
>> 2000 parts per weight of water at 20C. add to this mixture,
>> 140 parts per weight of hydrogen peroxide (25%) stirring continuously
> for
>> 20
>> minutes.
>> Reaction is complete in 30 minutes.
>>
>> It seems to good to be true. Does anyone know if it works
> consistently?
>>
>> ~m
>>
>>
>> ----- Original Message -----
>> From: "Alberto Novo" <alt-list@albertonovo.it>
>> To: <alt-photo-process-L@usask.ca>
>> Sent: Wednesday, February 15, 2006 1:12 AM
>> Subject: Re: patents
>>
>>
>> > Michael Koch-Schulte wrote:
>> >
>> > > I get the first page 1899674 but 334904 gives me something else, a
>> "yarn
>> > > stripper". Could you check the number again. Thank you. It's
>> coincidentally
>> > > something I'm very interested in.
>> >
>> > 334904 is the Canadian patent, so you need to check
>> > http://patents1.ic.gc.ca/intro-e.html
>> >
>> > If you want, I can send you both offlist.
>> >
>> > Alberto
>
 
Received on Thu Feb 16 04:44:45 2006

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