iron from clay
Bob
I'm trying to get some iron out of the local earth (Washington, D.C.)
to make a little memento from my property.
I have lots of red clay from which I've extracted about 50 grams of
black iron oxide (or hydroxide) by using a rare-earth magnet.
Now I have to reduce the iron, either electrolytically or with carbon
and heat. I have an oxyacetylene torch and an arc welder.
Here are some of my questions:
If I try this electrolytically, is HCl a good way to put the oxide in
solution, or is there something better?
What kind of electrodes can the iron be stripped from?
Once I get the iron reduced, what ways are there to melt
small amounts of it? Are small induction furnaces available
for iron or steel?
Thanks for any help in the effort.
Bob
Uncle Al
In principle if you got the oxide really hot, charcoal would reduce it
handily and lime(stone) would float gangue to remove impurites and
prevent surface oxidation. Blow oxygen through at the end to adjust
carbon level. The iron/steel would be obtained directly as a liquid
as in the Bessemer process - an incredible mess downwind.
If you went way heavy on the charcoal and started with clean iron
oxide, no limestone, you might get wootz. Add maybe 50 ppm vanadium
at the start (ashes from sea cucumber/sea squirt or tunicates in
general - blood colored from tunichrome), heavily work the metal at
barely dull red heat, and get Damascus steel. Borate flux would ease
surface oxidation.
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf
Lefty
I'm very impressed that someone posted this - exactly what I was about to
suggest.
If the iron content was high enough, you could just mix up some thermit and
reduce it with aluminum pwd. But there is probably so much Si and Ca in the
clay that this might not work very well is you used stright clay. However,
you say you have some good oxide, so thermit would certainly work. Might be
able to get it going with the arc welder. Could probably use aluminum foil
instead of pwd if need be.
Or you could grind up the whole mess about 1/2 oxide and 1/2 coke(or coal),
and add it to a nice hot coal/coke fire. Typically you would need to perform
this combustion insulated by some type of refractory material. Your cheapest
route is to make a paste from silica sand and sodium silicate, or if you can
get your hands on some alumina rich clay !
If you are really game for something new, get yourself a huge lens and melt
the oxide. Then turn on your fuel gas with >no< oxygen. Blow the fuel-gas on
the hot oxide, and the carbon from the acetylene will reduce the oxygen from
the Fe2O3 and you'll have pure Fe. Pretty sure carbon has a higher affinity
for O2 than Fe does. Should work. Whatever the case - you need some
refractories.
Brian Whatcott
People who've tried electrolytic derusting, uniformly enthuse about
the process.
You would too, I expect.
Take a battery charger - preferably with a 6 volt switch.
Connect a stainless plate to the negative terminal, and place the
oxide ore on it.
Connect a stainless plate or a lead one to the positive terminal
and check that the oxide bubbles when the solution is made conductive
with baking soda. Leave the thing to bubble for 12 hours or so.
As you can see, it is the mirror image of anodizing aluminum - where
the oxide forms on the anode (+) plate.
But for small particles of oxide, there is a much, much faster
process: Thermite.
Powder the iron oxide. Mix with as much aluminum powder in a ceramic
vessel.
Light the mixture with a 'sparkler" It has to be glowing white
hot to light the powder. The molten iron will run out after the
fireworks subside.
Brian Whatcott Altus OK
ms
news:B4Kdnco9w8Y...@comcast.com...
Maybe an adobe memento would be more feasible than an iron one ;-)
Lefty
Take a big chunk of graphite and carve out a bowl shaped concave trough on
the top side.
Connect the arc welder leads securely on opposite ends of the graphite
block, and put your oxide in the bowl.
Put this thing under a vacuum, argon, or reducing gas, and hit it with 500
amps for 35 minutes, or just cook to taste.
Graphite reduces Fe2O3, and you get relatively pure iron. Might even wind up
with steel if you do it this way.
Bob Eldred
"Bob" <e...@nowhere.com> wrote in message
news:TNKdnVuHT9S...@comcast.com...
You have pulled out some of the black oxide, Fe3O4. This stuff is heavy so
50gr ain't much. If the clay is red, you've left most of the iron in it.
Maybe as much as 10% of the clay is Fe2O3, the stuff that makes the clay
red. I think you can extract this with hot sulfuric acid to make ferrous
sulphate. That you can purify to green crystals by by evaporating then
re-disolving in clean water. Do several times. Once the crystals are clean,
heat them to about 800 degC (red heat) to convert them to nearly pure Fe2O3.
Do this until you have several pounds of pure oxide. That you can reduce to
iron in a small furnace or forge with charcoal or coke. Use Borax as a flux
and make the fire white hot with an air blow. You should be able to get a
hunk of impure iron that you can pound out to a nice half pound slug. Do not
expect to melt the iron. The furnace will not produce a hot enough fire but
it will be hot enough to reduce the oxide and pound the metal. Good luck.
Bob
big...@meeow.co.uk
> Hi
>
> I'm trying to get some iron out of the local earth (Washington, D.C.)
> to make a little memento from my property.
only one thing to add: a microwave oven makes a good furnace for small
work, and can can be used to both reduce and melt the metal. Google
microwave foundry.
NT
Brian Whatcott
wrote:
Nice post!
Brian W Altus, OK
Bob
Bob
"Uncle Al" <Uncl...@hate.spam.net> wrote in message
news:42530915...@hate.spam.net...
Puppet_Sock
[snip]
> as in the Bessemer process - an incredible mess downwind.
Indeed, this is not something to be tried indoors.
Also, you want to think fairly carefully about how to
contain this sucker. It gets foolishly hot.
Socks
Bob
just by using a magnet to separate it from silica etc in a thin plastic
dish of water. (It's amazing how easy it is, with a magnet, to get the
iron out of the local clay.)
I'll try the thermite route, and, separately (of course), the reduction in
charcoal, as per Uncle Al's suggestion.
Yesterday, I put some of the (presumed) oxide on a piece of wood
an irradiated it with an arc between to carbon electrodes. Afterwards
I dug around in the burned wood and found some small pieces of
iron, which I verified as metallic by hammering them out.
Thanks for the suggestions.
Bob
"Lefty" <Y...@h.Right> wrote in message
news:B4Kdnco9w8Y...@comcast.com...
> >
Bob
I like your electrolytic method. Gonna try that. Thanks.
Bob
"Brian Whatcott" <bet...@sbcglobal.net> wrote in message
news:t8f651djjo4bof3dd...@4ax.com...
Bob
graphite rod. The crucible might be too deep (about 10 cm), and
I've 'flooded' the crucible with CO2, of which I have a cylinder. The
arc, inside the crucible, fans out to all sides of the crucible, which
is interesting in itself. I will try again, with inert gas. I would like
to
end up with steel.
Bob
"Lefty" <Y...@h.Right> wrote in message
news:zOidndO2sNw...@comcast.com...
Bob
I previously used HCl, which I neutralized with NaOH to produce
a brown cake which was unmagnetic till after I heated it to red
heat for a while. The resultant black stuff (which was magnetic)
didn't however work well in the thermite method; i.e., I got nothing
except magnetic chunks of alumina and god knows what else.
Neat suggestion, though. Gonna try this method too.
Thanks, Bob
Bob
"Bob Eldred" <nsmon...@yahoo.com> wrote in message
news:0OJ4e.1944$qD2...@newssvr14.news.prodigy.com...
Bob
Jeez, the woman will scream if I wreck the microwave,
but I guess that's the price of knowledge . . .
Bob
<big...@meeow.co.uk> wrote in message
news:1112766315.9...@z14g2000cwz.googlegroups.com...
Michael
a traditional way. One of your local institutions (e.g. the library at
Colonial Williamsburg) can probably tell you what the historical method
would have been
"Bob" <e...@nowhere.com> wrote in message
news:TNKdnVuHT9S...@comcast.com...
Uncle Al
>
> This sounds real good. Thanks Al.
I'd go the thermite route to recover clean metal with minimum hassle,
then maybe play with Damascus steel after reading up on it. The need
for about 50 ppm vanadium in true Damascus steel to segregate
dendritic phases is a fairly recent discovery. Pattern welding per se
is very old. If you wish to do good job with high carbon and low
carbon steel preforms you must interpose a thin shim barrier of
silicon steel (e.g., jackammer bit) to stop carbon diffusion at the
interface.
Doing it takes a lot of work. Doing it well requires a lot of
knowledge and experience, too. Measure twice, cut once.
big...@meeow.co.uk
> You're kidding! A home microwave oven can do that?
> Jeez, the woman will scream if I wreck the microwave,
> but I guess that's the price of knowledge . . .
No need to wreck it, its only if you spill the stuff there will be
trouble. It may melt the glass turntable, the steel floor, the table
the microwave stands on, the floor, ceiling, carpet and floor below,
and cool down in the soil below the house. So try and take care :)
NT
> <big...@meeow.co.uk> wrote in message
> news:1112766315.9...@z14g2000cwz.googlegroups.com.
Bob Eldred
> I hadn't thought of using hot sulphuric acid on the clay directly.
> I previously used HCl, which I neutralized with NaOH to produce
> a brown cake which was unmagnetic till after I heated it to red
> heat for a while. The resultant black stuff (which was magnetic)
> didn't however work well in the thermite method; i.e., I got nothing
> except magnetic chunks of alumina and god knows what else.
>
> Neat suggestion, though. Gonna try this method too.
>
> Thanks, Bob
>
> Bob
Well give it a try. Unfortunately hot acid may remove other substances from
the clay that could interfere with the process or require more sophisticated
separation of the solutes.
A simpler idea is to give up on iron and make a vessel, coffee cup or
somthing from the clay and fire it into a ceramic momento. It's much easier
to do and more likely to be successful, plus you can make something useful.
The problem with the thermite method is that it requires relatively pure
oxide plus it is a bitch to get going. Oxide made from ferrous sulphate can
be very pure if done right. It should work in the thermite method.
If your HCl results were magnetic they had iron in them or one or more of
its oxides. Alumina is not magnetic.
My above suggestion, reducing with carbon in a forge then pounding the metal
removes much of the slag and inclusions that will always be in iron made
that way. That's the way iron was made before the 19th century and the blast
furnace. Fires were not hot enough to melt it but the pounding and working
squeezed out the non-metalic crud and welded the resultant metal to a
cohesive hunk. They called it "wrought" iron and was a common product before
the age of steel.
Bob
Bob
I had an encouraging initial result yesterday. I weighed out
my black oxide (37 gms, which I suspect might actually be
FE3O4) then mixed in what seemed the right amount of
aluminum dust. It burned fast and hot. The iron came out
in about 5 chunks chunks, which I fused together with an arc
between to carbon electrodes. You can see the result at:
http://www.comfortlight.com/iron_040705.jpg
This is enough iron to forge into a ring or a coin, but now
I'm getting turned on to this whole project: I want to forge, if
not a sword of Damascus-type steel, at least a small knife.
I guess the next part of this project will be to build a proper
furnace for use in heating and forging my iron.
I should have photographed the black oxide particles under
my microscope. The particles appear to me to be sized
at about 100 microns, max, and typically about half that size.
I'm wondering how it formed in that way. I'm also wondering
what portion of it might be relatively recent, i.e., having fallen
from the sky. I'd appreciate any thoughts on this.
Bob
"Uncle Al" <Uncl...@hate.spam.net> wrote in message
news:425590E7...@hate.spam.net...
Bob
>
> "Bob" <e...@nowhere.com> wrote in message
> news:YYCdnVIRuLk...@comcast.com...
> > I hadn't thought of using hot sulphuric acid on the clay directly.
> > except magnetic chunks of alumina and god knows what else.
> >
> > Neat suggestion, though. Gonna try this method too.
> >
> > Thanks, Bob
> >
> > Bob
>
> Well give it a try. Unfortunately hot acid may remove other substances
from
> the clay that could interfere with the process or require more
sophisticated
> separation of the solutes.
That seems to have happened with the HCl.
> A simpler idea is to give up on iron and make a vessel, coffee cup or
> somthing from the clay and fire it into a ceramic momento. It's much
easier
> to do and more likely to be successful, plus you can make something
useful.
Right. Bu then I wouldn't get the knowledge of how to get iron
out of the ground. This is sort of a philosophical project, one
related to materials, or to materials science.
> The problem with the thermite method is that it requires relatively pure
> oxide plus it is a bitch to get going. Oxide made from ferrous sulphate
can
> be very pure if done right. It should work in the thermite method.
You can see the chunk of iron I got yesterday, using the thermite method,
at:
http://www.comfortlight.com/iron_040705.jpg It's enough to make some
small thing, but what you wrote earlier about getting several pounds
or iron is interesting to me.
> If your HCl results were magnetic they had iron in them or one or more of
> its oxides. Alumina is not magnetic.
I wrote that wrong: 'magnetic chunks of alumina.'
> My above suggestion, reducing with carbon in a forge then pounding the
metal
> removes much of the slag and inclusions that will always be in iron made
> that way. That's the way iron was made before the 19th century and the
blast
> furnace. Fires were not hot enough to melt it but the pounding and working
> squeezed out the non-metalic crud and welded the resultant metal to a
> cohesive hunk. They called it "wrought" iron and was a common product
before
> the age of steel.
This is going to happen in my back yard sometime this summer . . .
thanks.
Bob
Bob
<big...@meeow.co.uk> wrote in message
news:1112914891.8...@l41g2000cwc.googlegroups.com...
> Bob wrote:
> > You're kidding! A home microwave oven can do that?
> > Jeez, the woman will scream if I wreck the microwave,
> > but I guess that's the price of knowledge . . .
>
> No need to wreck it, its only if you spill the stuff there will be
> trouble. It may melt the glass turntable, the steel floor, the table
> the microwave stands on, the floor, ceiling, carpet and floor below,
> and cool down in the soil below the house. So try and take care :)
I googled 'microwave foundry.' I'm going to get a used oven
for this project. Much thanks for this lead. BTW, check out
the little chunk of iron I got yesterday, using the thermite on
37 grams of pretty pure black oxide.
http://www.comfortlight.com/iron_040705.jpg
(I purified the oxide by sliding a rare-earth magnet on the top
side of a horizontal sheet of paper while the 'ore' slid back
and forth on the bottom side; the non-ferrous stuff just dropped
right out.)
Bob
Bob
"Michael" <mb...@light-deletedashtodash-houseoptics.com> wrote in message
news:jxc5e.14821$6a5....@twister.nyroc.rr.com...
> If you're going down the memento path, you might consider trying to do it
in
> a traditional way. One of your local institutions (e.g. the library at
> Colonial Williamsburg) can probably tell you what the historical method
> would have been
Indeed, this was my original plan -- to do it the way our ancestors did
it. It seems, though, that I am going to be working my way backwards
toward the early methods. Thermite is so simple, right now; and
electrolysis might be interesting to try.
Bob
Michael
have fun; as a source of amusement I definitely recommend the microwave
foundry
"Bob" <e...@nowhere.com> wrote in message
news:DIOdnWFh9Ik...@comcast.com...
Gregory L. Hansen
>Uncle Al,
>
>I had an encouraging initial result yesterday. I weighed out
>my black oxide (37 gms, which I suspect might actually be
>FE3O4) then mixed in what seemed the right amount of
>aluminum dust. It burned fast and hot. The iron came out
>in about 5 chunks chunks, which I fused together with an arc
>between to carbon electrodes. You can see the result at:
>http://www.comfortlight.com/iron_040705.jpg
>
>This is enough iron to forge into a ring or a coin, but now
>I'm getting turned on to this whole project: I want to forge, if
>not a sword of Damascus-type steel, at least a small knife.
>
>I guess the next part of this project will be to build a proper
>furnace for use in heating and forging my iron.
A friend of mine has gotten on to knife making. He's made a few firebrick
forges that consist of a firebrick with a hole drilled the long way to put
the metal in, intersecting a hole drilled the short way for the propane
torch. It heats the metal cherry red without a problem.
--
"In any case, don't stress too much--cortisol inhibits muscular
hypertrophy. " -- Eric Dodd
Bob
"Gregory L. Hansen" <glha...@steel.ucs.indiana.edu> wrote in message
news:d3637v$jtr$4...@rainier.uits.indiana.edu...
> >I guess the next part of this project will be to build a proper
> >furnace for use in heating and forging my iron.
>
> A friend of mine has gotten on to knife making. He's made a few firebrick
> forges that consist of a firebrick with a hole drilled the long way to put
> the metal in, intersecting a hole drilled the short way for the propane
> torch. It heats the metal cherry red without a problem.
Worth considering. But I'd worry that propane might not
be sufficiently reducing, as say with charcoal heat.
I will look into the importance of having a reducing atmosphere
in heating the iron/steel for forging. Thanks.
Bob
ji...@specsol.spam.sux.com
> Bob
Same scheme with an acetylene torch running oxygen lean.
--
Jim Pennino
Remove .spam.sux to reply.
big...@meeow.co.uk
> <big...@meeow.co.uk> wrote in message
> news:1112914891.8...@l41g2000cwc.googlegroups.com.
> I googled 'microwave foundry.' I'm going to get a used oven
> for this project. Much thanks for this lead. BTW, check out
> the little chunk of iron I got yesterday, using the thermite on
> 37 grams of pretty pure black oxide.
> http://www.comfortlight.com/iron_040705.jpg
>
> (I purified the oxide by sliding a rare-earth magnet on the top
> side of a horizontal sheet of paper while the 'ore' slid back
> and forth on the bottom side; the non-ferrous stuff just dropped
> right out.)
>
> Bob
nice one. You can build a house with that stuff.
NT