Sciencemadness Discussion Board - Lead Dioxide on Magnetite

Lead Dioxide on Magnetite

dann2 - 14-6-2007 at 13:27

Hello,

I decided to put this into a new thread.

I finally got around to an attempt at plating Lead Dioxide onto Magnetite. It was something I had though about for some time.
I used an ordinary Lead Nitrate bath.
The Lead Dioxide deposited well onto the Magnetite.
I put it into a Perchlorate cell (All Chlorate, about 2% Chloride) and got Perchlorate forming in about an hour using a Methylene blue test. The Lead Dioxide seem to be staying on the Magnetite and not coming off.
I am surprised that this worked at all.
Wonder where is the snag.
It is only the end of the substrate I coated. Some of the substrate is in contact with the electrolyte but does not erode. (Magnetite is very slow to erode.)
It would seem that Magnetite makes a good (perfect??) substrate for a Lead Dioxide anode. :cool:

Dann2

Eclectic - 14-6-2007 at 13:58

Now you'll have Rosco going on again about how all you need is iron (oxide)!

alancj - 16-6-2007 at 17:21

Good work dann2, that's very interesting! What were the specific plating conditions used? (Concentration, control, tank size etc.) How did you make the magnetite substrate? Cast with an oxy/acetylene torch like is described on your site?

Quote:

Originally posted by Eclectic
If anyone wants to actually MAKE an iron substrate lead dioxide anode, you might try soaking the iron in concentrated nitric acid first to passivate it. This effectively forms a coating of magnetite (?), preventing further dissolution. Maybe preventing Fe contamination of the plating bath? Experimentation will tell...

If this works it might make substrate manufacture a lot easier than casting, the only thing is that the magnetite may be too thin and the iron underneath would get eaten away... so you would end up with a temporary substrate... then you basically doing what Rosco has been saying all along! (gasp)

Have you tested it further?

-Alan

[Edited on 16-6-2007 by alancj]

jpsmith123 - 16-6-2007 at 19:32

What about PbO2 over MnO2 over Ti?

Eclectic - 17-6-2007 at 03:36

Alan,

No, I don't really care about PbO2 over magnetite. I like titanium for a substrate. I just remember how resistant powdered iron is to dissolution in nitric acid from long ago experience as a tech in a hydrothermal geochemistry lab. If you want good adhesion of PbO2 to iron though, it probably would help to preform an interface layer of magnetite to prevent the PbO2 and plating bath from directly oxidizing the iron in a less controlled fashion. Just soaking in plain ole nitric acid should do it.

dann2 - 17-6-2007 at 04:52

Quote:

[

quote]Originally posted by alancj
Good work dann2, that's very interesting! What were the specific plating conditions used? (Concentration, control, tank size etc.) How did you make the magnetite substrate? Cast with an oxy/acetylene torch like is described on your site?

If this works it might make substrate manufacture a lot easier than casting, the only thing is that the magnetite may be too thin and the iron underneath would get eaten away... so you would end up with a temporary substrate... then you basically doing what Rosco has been saying all along! (gasp)

Have you tested it further?

-Alan

[Edited on 16-6-2007 by alancj]

Substrate was make as here:
http://www.geocities.com/CapeCanaveral/Campus/5361/chlorate/...

The plating conditions were not really noted. I assumed with would not work so only dunked the substrate into an existing (very small) plating tank and passed some current.
Then had a look at it.
Coating was very thin. I need to make a new substarate and start again.
The substate (Magnetite) was very poorly made (as in the picture in the link) as it was a first attempt.
Magnetite substrate is easy to make but you need a welder.

If Nitric acid will form a non porous Magnetite layer on the element that is between Manganese and Cobalt in the periodic table then it should work.

STOP mentioning THAT element.

Dann2

dann2 - 6-7-2007 at 10:30

Hello,

Still did not get around to plating Lead Dioxide onto Magnetite but I came accross two pieces of Lead Dioxide from an old anode. They measure about 2 x 3 x 0.3 and 2 x 2 x 0.3 cm.
I attached the two pieces to a Magnetite piece using an elastic band (first thing that came to hand) and dunked into a Chlorate cell. (All Chlorate bar about 2% Chloride). The anode appears to function ok.
The LD is gassing so there is current going out through its surface. Current density is not really measurable as there is gassing on Magnetite as well. It is early days but we will see how it goes in the long term.
There is no reaction between the Magnetite and the LD where they are in contact.
This would make a good reliable anode if it works. No need for good adherent coats of LD. Just obtain some LD pieces + a Magnetite stick and work away.

Dann2

hashashan - 6-7-2007 at 13:26

Don't you think that as soon as the chloride falls below 10% your magnetite will get eroded away? why just not attach the magnetite above the liquid?

dann2 - 7-7-2007 at 10:34

Quote:

Originally posted by hashashan
Don't you think that as soon as the chloride falls below 10% your magnetite will get eroded away? why just not attach the magnetite above the liquid?

Hello Hashashan,

I attempted to make Perchlorate (from Chlorate) using Magnetite some time ago and it failed to make any. The anode was in the Chlorate solution for ages, it did not erode.

If the LD pieces on the Magnetite work with just the two small bits I have it will work if you had a larger quantity of LD pieces and put them on a large piece of Magnetite in the solution. The Magnetite just being used to carry the current to each piece.

Dann2

dann2 - 12-7-2007 at 06:37

Hello,

My 'composite' Magnetite + Lead Dioxide anode has been running for about 3 days now. It is in a tiny cell (about 130ml) and about one amp of current.
No Perchlorate is forming. The first two days I used Magnetite cathodes (just because they were there). I though it may have been bacause of the Mag. cathodes and changes to SS but still no Perchlorate. Most of the current I suppose is going into the solution via the (anode) Magnetite. Some current is going into the solution via the LD as it is gassing.
Perhaps the current density on the LD is just too low.
Magnetite wont make Perchlorate BTW.

There is no wear or reaction between the LD and Mag. where they are in contact.
Perhaps this will just not work or perhaps if I had much more LD in order to cover all of the Mag. with an actual 'depth' of pieces.

I have no more LD pieces. Will now actually NEED some failed anodes

Dann2

dann2 - 15-7-2007 at 05:36

Hello,

I increased the current on the anode and got lots of Perchlorate forming. I have no idea of current efficiency or density etc but it would seem that this concept is definitely workable.
As I will repeat (like a parrot) it free's one from needing good high quality coatings of Lead Dioxide, (which are not so easy to achieve).

Dann2

Magnetite

chloric1 - 15-7-2007 at 16:17

WOW Dan! That is most spectacular! I hav been throwing a ideas around in my skull on how to produce a perchlorate making anode. Not to keen on plating lead dioxide on graphite because imperfections in plating would lead to anode failure. I remember back in 2002 or 2003 when I playing around with patinas for copper and brass. One of my books instructed me to spray a ferric nitrate solution on a moderately hot(200-300 Celsius) piece of copper to build a black background. I bet if you do this several times you could build up a decent amount of oxide to cover what base metal you have. When the base is covered you might need to add a proportionate amount of ferrous salt since there would be little metal to reduce the ferric ion.

Anyone want to comment on this? I will try as soon as I get home whcih is like 7 or 10 days.

Magnetite on Ti

dann2 - 15-7-2007 at 18:30

Hello Chloric1,

I cannot coment on the Copper substrate anode. Don't like Cu being so near the Chlorate cell.

Take a look at US Patent No. 3,850,701 . It sounds a bit complicated but I like example four where they casually state that 'A solution was electrolyzed at 60C for 11 months......'. Now thats what I call a test!
_____________________________________________
US 3,850,701
____________
EXAMPLE 1

A previously polished titanium plate 200 mm by 50 mm and 1 mm thick was defatted in a boiling 10 percent NaOH solution, and was dipped into a 5 percent hydrofluoric acid solution at room temperature for 1 min, and then washed with water. Electro-deposition was carried out for 19 min in an electrolyte at 25C consisting of 130 g/l of ferrous sulfate (heptahydrate), 100 g/l of ammonium sulfate and 6 g/l of formalin by using said titanium plate as a cathode (a cathodic current density = 2.5 A/dm squared) and a low carbon steel as an anode. After the electrodeposion was completed, said iron deposited titanium plate was washed well with water, and then dipped into a solution of 20 g/l of ammonium ferric oxalate at 13C, and was allowed to stand for 20 min under a reduced pressure of 15 mm Hg abs. produced by a vacuum pump and dried under the reduced pressure and was then subjected to heat treatment at 650C for 2.5 hrs. in an atmosphere of a hydrogen/steam gaseous mixture consisting of 20 percent by volume of hydrogen and 80 percent by volume of steam prepared by passing hydrogen into hot water at 94C. On the surface of the product the formation of a magnetite-coated layer was clearly recognized. The thickness of said layer was confirmed to be 20 micron by weighing said product. The appearance of said product was uniformly black and fine-grained and no crack was observed therein.

EXAMPLE 4

An electrolyte consisting of 250 g/l sodium chloride, 70 g/l of sodium chlorate, and 2 g/l of sodium bichromate was electrolyzed at 60C for 11 months with an anodic current density of 10 A/dm squared by using an anode coated with magnetite prepared as described in Example 1 as an anode with the use of a mild steel plate as a cathode. The current efficiency was 85 percent and the average cell voltage was 3.38 V. The required energy per ton sodium chlorate was 6,000 kwh. During this period almost no change was observed on the surface of the anode.
____________________________________________

It is not that hard to make Magnetite anodes using mild steel and an oven at about 900C + Steam.

I need to test the anode I have in a Chlorate cell to see if there is any reaction between the Magnetite and LD in the more severe (IMHO) environment of the Chlorate cell.

The elastic band went west today.
I re-attached the LD pieces using some Teflon cord. You can make Teflon cord real easy by getting some Teflon tape (plumbers use it for putting on pipe threads) from the local hardware store and twiddling it between your thumb and finger. Quite strong and (I hope) long lasting.

I am surprised this anode worked at all. I have never seen in the Journals or elsewhere a mention of Lead Dioxide on Magnetite or with Magnetite etc. There HAS to be some snag......

Dann2

[Edited on 16-7-2007 by dann2]

Copper

chloric1 - 15-7-2007 at 18:47

I should have been more specific. I only mentioned copper because of some of my patina work. I am sure this process would apply to mild steel. That is GREAT news if I can use mild steel. I have already been playing with electrolytic rust reduction and it can be used to create a rough pitted iron if you periodically switched polarity. So I can find the most rusted iron rod(rebar?) in a scrap yard or perhaps lying on a factory floor and clean it up, pit it, and spray on my ferric nitrate about 6 times so it is solid black and plate it with LD! Maybe an alpha LD followed with a coat of beta LD.

12AX7 - 15-7-2007 at 18:47

Maybe PbO2 doesn't plate on magnetite, and any mechanical (hardware) connection on an anode is just silly.

"Aww nuts. Joe, we lost the anode again! Go get the surgical tubing!"

So, they essentially plate titanium with iron (formalin is a leveller??)? What's the oxalate dip for?

It occurs to me that a gas flame is rich in hydrogen, steam and fire. Hydrogen is mentioned; is a reducing atmosphere actually desirable for magnetite?

Tim

mechanical connection

chloric1 - 15-7-2007 at 19:37

Tim,

Before you dismiss the mere mechanical connections, consider US 3454472. The whole premise of this anode is a mere mechanical imbedding of magnetite onto lead and anodizing this in weak NaCl to make LD mixed with the magnetite.

dann2 - 15-7-2007 at 20:06

Quote:

Originally posted by 12AX7
Maybe PbO2 doesn't plate on magnetite, and any mechanical (hardware) connection on an anode is just silly.

"Aww nuts. Joe, we lost the anode again! Go get the surgical tubing!"

So, they essentially plate titanium with iron (formalin is a leveller??)? What's the oxalate dip for?

It occurs to me that a gas flame is rich in hydrogen, steam and fire. Hydrogen is mentioned; is a reducing atmosphere actually desirable for magnetite?

Tim

Surgical tubing is no good. You need Chlorine resistant elastic bands... big ones

I attempted to make a Magnetite anode using a bar of steel and an oxygen rich oxy propane torch. I put a coating of Magneite on the steel bar as best I could using the flame. The whole lot failed soon after it went into a cell. You need to convert all the steel to Mangnetite.

Regarding the mechanical connection.
Why do you say its silly. HOW DARE YOU

The Lead Dioxide pieces (many of them) are simply placed on a Magnetite bar all along its length. The whole lot is placed into the cell. The connection goes to the top of the Mag. (using a copper plated connection say).
This seems to work as far as I can see.
It seem a bit desperate I admit but it does seem to be feasible. Time will tell.

LD will also plate onto Magnetite. Don't know how reliably it will stay there though.

Dann2

Chloride to Perchlorate with MSLDA

dann2 - 19-7-2007 at 18:22

Hello,

I put a picture of my Lead Dioxide on Magnetite anode here.

http://www.geocities.com/CapeCanaveral/Campus/5361/chlorate/...

It would appear that this type of anode may be successful.
I make both Chlorate and Perchlorate with it.
If Magnetite proves easy to make using hot over (kiln) + steam and steel the subatrate would not be too hard to manufacture. It is all 'easy, back yard stuff'.

Dann2

dann2 - 22-7-2007 at 16:23

Quote:

Hello,

According to an artical 'The preparation and behaviour of Magnetite anodes' the Oxalate dip is to give the Magnetie better adhesion to the Ti.
The artical has been posted on this site. Cannot find it though.

Dann2

maybe it was in a patent ?

Rosco Bodine - 22-7-2007 at 16:44

I was reading this US3850701 yesterday ....
so the oxalic acid sounded familiar

Attachment: US3850701 Titanium_ANODE_COATED_WITH_MAGNETITE.pdf (167kB)
This file has been downloaded 679 times

dann2 - 23-7-2007 at 08:35

Hello,

Artical is here:

http://www.pyrobin.com/files/the%20preparation%20and%20behav...

This was posted on this board before.

It would seem quite simple to make Magnetite anodes using heat and steam. I am currently putting together a small furnace to heat the Steel in and feed in steam using a kettle attached to a variac. The Hydrogen is not needed for this. Another patent simply used Steam. At least the Steam is OTC.

Since it would appear that you can use LD on Magnetite (coated onto it or simply held against it) I am thinking of jacking in the DTO thing.
The DTO on Ti with LD on top is starting to piss me off

Dann2

chloric1 - 24-7-2007 at 02:20

Dann2

That is right K.I.S.S. Keep It Simple Stupid. There are more ingenious ways to spend your time and energy. Let all the hightech stuff be with big industry.

dann2 - 24-7-2007 at 10:47

Quote:

Originally posted by chloric1
Dann2

That is right K.I.S.S. Keep It Simple Stupid. There are more ingenious ways to spend your time and energy. Let all the hightech stuff be with big industry.

Hello,
I guess if the DTO via solder works it is not too complicated.
I started my 'Magnetite with LD pieces held against it with Teflon cord' anode today in a KCl cell but the power supply exploded. A PC power supply. No fault of the anode. I got another old pc from the dumpster only to discover that it is a Pentium Pro pc.
I don't want to take it apart!

Will soldier on....

Dann2

chloric1 - 24-7-2007 at 13:56

What happened to your power supply. I have heard of other people blowing computer power supplies.

dann2 - 24-7-2007 at 17:10

Quote:

Originally posted by chloric1
What happened to your power supply. I have heard of other people blowing computer power supplies.

Hello,

I had been using this computer supply for quite a while usually the 5 volt output. When I used the 5 volts output all other outputs were not in use.
When I wanted to use the 12 volt output I had to put a load on the 5 volt output or the supply would not work. I used a bulb on the 5 volt output for this job.
I was using the 12 volt output for my LD on Magnetite anode (with a resistor) for about 8 days.
I started up a new cell, connected up supply, pluged in and it let a bang with a flashover between two tracks on the board.
There was no short circuit or anything wrong with my connections to the anode or the bulb. It just simply went west of its own accord.
Perhaps it is good to have a small load on ALL the outputs when using this type of supply. This is a wild assed guess.

Dann2

Rosco Bodine - 25-7-2007 at 11:33

Quote:

Originally posted by dann2
Hello,

I started up a new cell, connected up supply, pluged in and it let a bang with a flashover between two tracks on the board.
There was no short circuit or anything wrong with my connections to the anode or the bulb. It just simply went west of its own accord.

Dann2

That is "went south" .... not west

Is English a second language for you ?

I keep getting the impression that you get a bit off track
with some sentence structure and interpretation ,
context , ect. which indicates English may not be your
native language .

I'll take a wild guess .....maybe you are Danish or Swedish ?

[Edited on 25-7-2007 by Rosco Bodine]

Xenoid - 25-7-2007 at 12:01

Quote:

That is "went south" .... not west

Is English a second language for you ?

[Edited on 25-7-2007 by Rosco Bodine]

Well, I'm from the antipodes, I have only ever heard the term "to go west"!

I guess "to go south" is an American term, not used much by the rest of the English speaking world.

Xenoid

Rosco Bodine - 25-7-2007 at 12:15

http://www.worldwidewords.org/qa/qa-sou1.htm

It is an association in modern times with graphical figures
where "up" is north and "down" is south ...towards the baseline . The term has been around for maybe forty years .

Another similar one is "four paws skyward"

or "bought the farm" or "checked out" .

[Edited on 25-7-2007 by Rosco Bodine]

Xenoid - 25-7-2007 at 12:30

Quote:

Originally posted by Rosco Bodine
http://www.worldwidewords.org/qa/qa-sou1.htm

It is an association in modern times with graphical figures
where "up" is north and "down" is south ...towards the baseline . The term has been around for maybe forty years .

I had always assumed it mean't to go west from Europe to America, or from East Coast US to West Coast, or East Coast Australia to Western Australia!

ie. To imply going from somewhere civilised to less civilised (in the old days), or by connection, somewhere (thing) that works to somewhere that doesn't!

Xenoid

Rosco Bodine - 25-7-2007 at 12:33

typical burgeoise nonsense

Xenoid - 25-7-2007 at 12:43

"to go west"

To die, soldiers' euphemism used during WW1.

That must be what..... 90 years

And thats from an American dictionary!

"to go west"

To die, to disappear, to be lost...

Another dictionary!

Xenoid

Rosco Bodine - 25-7-2007 at 12:51

Well .....if it means to go to the place of the setting sun ,

then what does it mean to go to the place of the rising sun .....

wait don't tell me ......it means to go to .....

Japan ?

American via English eh!

dann2 - 25-7-2007 at 18:02

Hello,

To 'go west' as Xenoid has said is my interpretation. To 'go south' is a distortion.

Down the Swanie,
Ka-buttsed,
A gonner,
Fucked,
Bucked, similar interpretation as 'gone west'.
American is not my first languge, English is

(let's not menton the spelin).

Moving on to less interesting things, my 'Magnetite with LD tied to it' anode has been running in a KCl cell for about half a day and K Chlorate is just starting to ppt at the cell bottom. There is some brown crud at the bottom too so I guess there is some erosion somewhere. There is always some brown crud at cell bottom with LD in my experience.
The Magnetite is make via melting with welder. The bad news is that salts are starting to creep up the the connection at the top and turning the Copper green. This is a nuisance with any anode.
I am hanging my hopes on the Magneite made from Steel, heat and steam. Hopefully it will not conduct salts.
If the welder manufactured anode had been given more heat to melt it more I suppose there would be no salt conduction but it took quite an amount of 'welding' to get this one to point where I though it was melted enough.
You need a 100% duty cycle welder, at 110 or more amps and in my suituation I had to change the 25 amp fuse to a piece of wire.

Dann2

Eclectic - 25-7-2007 at 20:12

Tyburn, west of London, where criminals went to be hanged.

Hence, to "go west" means to die.