Pyrophoric Metal Preparation

[Swany]

This is not about milling your Al or Mg, or even MgAl until it blows up in your face when you open your mill.

 

This would be about decomposing organic acid salts of transitional metals (Cu, Fe, Pb..) in a closed, oxygen free, atmosphere such that you are left with extremely divided metal that ignites when you toss it in the air, or whatever you want to do with it.

 

Lead tartate, iron oxalate, and copper oxalate are the compounds which will be utulized. Potassium tartate is cream of tartar, IIRC, and a double replacement should ppt. lead tartate. Oxalic acid is avalible OTC for bleaching and cleaning, and Mumbles quotes reacting this with a sulfate of either Fe or Cu to get your happy oxalate. Boiling with the hydroxides would work as well, I should assume. Or any other readily avalible soluable salt, in a double replacement reaction.

 

Thankfully, these salts are rather insoluable, I gather.

 

I need to get some dH2O, and then I shall try the preperation of some Fe or Cu oxalate.

 

Or I may try it with a FeCl2 or Cl3 solution and some oxalic acid soln.

 

Happy days shall be ahead.

 

EDIT: little bit of test tube chemistry. Filled a test tube 3/4 way with warm water, added some CuSO4, shook stoppered (with finger) to dissolve. Added oxalic acid, and lo and behold, instant ppt! It is a light blue suspension, so it shall sit overnight.

[Skinflint]

I would assume that whatever the metal used it would have to be in its highest stable oxidation number before you percipitated the organic salt. If Iron(II)Chloride was added to oxalic acid it would make Iron(II)Oxalate which would then react with air while drying until iron was oxidized to +3. I don't think this oxide/oxalate salt would decompose very well when it was heated. Once I tried making Fe oxalate and I think I ran into this problem because the salt looked a lot different after I dried it. It seamed very rusty. Yet, I'm not sure if it was Iron(III)Chloride or not that I used. What oxidation number do you get when Fe is dissolved in HCl?

[Swany]

+2. WHEN PURE, it is a pale yellow/green, but with Cr impurites and such, it is usually a darker green. The rust color is characteristic of +3. If you loosely stopper the flask you dissolve it in, it will be +2. When its exposed to air, it is sensitive to oxidation. Chances are, you used a mix.

 

Nothing happened when I added oxalic acid to the mix of FeCl3/HCl. I suspect mine was contaminated with HCl, as I did not dissolve the steel wool to saturation, but rather I just topped it off a few times.

 

I am going to go test the Cu complex, right now. It is contaminated, chances are, but it should at least decompose happily. I need a suitable container as well. I am thinking a test tube loosely stoppered with a plug of Al foil shall do. I am so exited I have to go to the bathroom... could be hot sauce though.

 

EDIT: and it's nice to see you around, Skinflint! Been a while, need to catch up.

[Mumbles]

Pyrophoric Iron

Author: Maty

Materials: oxalic acid dihydrate 20g, iron sulfate heptahydrate 44g, distilled water

Equipment: a larger heat resistant test tube, 250ml and 500ml beaker, glass rod, heat source

Procedure: Place 20g of oxalic acid and 200ml distilled water into the 500ml beaker. Distilled water is necessary, tapwater contains cations that combine with the oxalic acid to form unsoluble precipitates. Boil the solution with stirring until the oxalic acid dissolves. In another 250ml beaker dissolve 44g of iron sulfate in 200ml boiling water. Pour the iron sulfate solution into the oxalic acid solution, with stirring. A fine yellow precipitate of iron oxalate should form. Filter out the precipitate and thoroughly wash with water on the filter (sulfuric acid will have formed in the precipitate and needs to be removed). Dry the powder in a warm place, avoid too much heat. Crush the dried powder to flour consistency. Place the powder in the heat resistant tube and gently heat the tube, continue the heating until all the powder turns black. If necessary, carefully stir the powder. Warning: The black powder that has formed is pyrophoric, which means it will spontaneously ignite in air, if hot. It gives off nice yellow sparks.

Properties: You can use this powder in pyrotechny to create yellow sparks, in self-igniting mixes as well as in the production of iron sulfide. A similar procedure can be used to produce powdered copper (colours flame green).

 

Pyrophoric Lead

Author: Oktogen

Prepare a solution of 2g lead acetate in water and acidify it with a few drops of acetic acid. To this solution add a stoichiometric amount of tartaric acid or primary potassium tartrate (in the form of a 5% solution) in several portions, with stirring. Filter the white precipitate at reduced pressure and wash on the filter with water. Dry at 110°C. Spread out the dry material in the lower section of a specially modified test tube.

(Hold an ordinary test tube with a metal clamp and heat in a burner flame about 3cm below its mouth. Keep rotating the tube along its axis. After the glass had softened, stretch out the tube so that the neck shrinks to about 3mm diameter. After cooling make a dent in the narrow section with a file and break it apart.)

 

Fix the tube in a stand in a tilted position. Heat the tube evenly. After the decomposition of the lead tartrate had ceased and all the water vapour and other decomposition products had escaped, take away the tube and pour out the pyrophoric lead onto a fireproof surface. Alternatively, you could carefully fuse the tapered neck of the tube to preserve the material for later use.

[healthypt]

Thanks for the prep info.Just bought 1.5 lbs. of oxalic acid from

Ron's Rocks on eBay for $5 plus $4.50 S&H;best deal found for my

activities