jpsmith123 - 25-1-2008 at 19:29
I happened to come across this Anotec sales brochure, and it looks like they make some relatively small silicon-iron anodes that might be worth evaluating as substrate
material.
From what I've read, these anodes form a conductive SiO2 layer which makes them fairly robust.
I wonder how well SnO2/Bi2O3, PbO2, etc., would work over one of these things?
bio2 - 25-1-2008 at 19:40
Transformer core laminations are made from sheets of high silicon steel.
Having just dismantled of couple of them I was also thinking of trying
this alloy as an anode. Mild steel itself is not iron of course, but is quite stable as
anode in water electrolysis using NaOH or KOH as electrolyte.
The steel surface passivates giving a rather lustrous oxide coating rendering the
surface relatively impervious after some hours of conditioning.
I intend to try the silicon steel soon to observe it's properties and performance.
edit: found this
High silicon cast iron anodes
Composition (Weight%)
ASTM A518 Grade 3
Silicon 14.20 - 14.75%
Chromium 3.25 - 5.00%
Carbon 0.70 - 1.10%
Manganese 1.50% max
Copper 0.50% max
Molybdenum 0.20% max
Non-oriented electrical steel usually has a silicon level of 2 to 3.5%
[Edited on by bio2]
12AX7 - 25-1-2008 at 19:48
I have both transformer iron and lump ferrosilicon (75%, IIRC).
Transformers rust every day, I don't think you'll get much use from them. The silicon content is around 3%.
Tim
chemrox - 25-1-2008 at 23:15
substrate for what? it helps to know where you're heading ... generic media for solvent free reax include clays that have iron in them but the iron
is in a sheet silicate matrix and generally isn't a reax participant if you're thinking green chem and microwave... what are you thinking?
jpsmith123 - 26-1-2008 at 05:23
Sorry if I wasn't clear. I meant as an anode substrate - to be used in lieu of titanium or graphite - thus with a catalytic coating of something like
SnO2/Bi2O3, PbO2, etc.
dann2 - 26-1-2008 at 10:45
Hello,
I have been trying now for months to convice you all that all you need is IRON. 
Moving swiftly along.........................
The high Silicon Iron anode used to be actually used for making Chlorate(I think) . They were called Duriron. (I used to think Duriron was Manganese
Dioxide, silly me).
They may work, who knows. I have me doubts.
Duriron is mentioned in this artical which was posted on this board some time in the past.
http://www.springerlink.com/content/u52729t3821wn641/
The high Si Iron may be no easier to come by than Ti nowadays and it would be far too much bother to attempt to make your own.
The transformer laminations (as pointed out) rust very very easily.
You will definitely need a precoat to stop LD and Substrate from reacting together IMHO.
Dann2
jpsmith123 - 26-1-2008 at 11:17
Hi Dann2,
I was thinking that the oxide layer of the anode, i.e., the conductive SiO2 layer or whatever it is, would be the precoat.
BTW, the reason I started thinking about these is because I am looking for substrates for my DLC experiments. Silicon is supposed to be a good
substrate for a DLC, so maybe there's enough silicon in this alloy to do the job.
I sent some emails out asking for prices. I'm thinking that the 2 lb. anodes shouldn't be too expensive, but they may surprise me.
[Edited on by jpsmith123]
skippy - 26-1-2008 at 16:02
There's a kind of plumbing pipe called acid resistant cast iron that matches the composition given by you, Bio2. I don't know how common it is but
it might be possible to get a scrap piece somewhere. It's supposed to be brittle, like earthenware and pots of the same composition were formerly
used to concentrate sulfuric acid.
[Edited on by skippy]
jpsmith123 - 26-1-2008 at 18:28
I think that would be the so-called "duriron" pipe made by a company called "Flowserve", although there may also be other manufacturers too.
dann2 - 5-2-2008 at 16:10
Hello,
Checked conductivity of Diamond Loaded Coating on Si. Totally non conducting.
(I said earlier in another thread that I had worked in a place that put DLC onto Silicon and I had some samples, can't keep track of threads.)
Cheers,
Dann2