Phosphorus

[klassasin]

This thread will tell you the way phosphorus is produced commercially.

2Ca3(PO4)2 + 6SiO2 + 10C -heat-> 6CaSiO3 + 10CO + P4

Heating of calcium phosphate (phosphate rock) with sand and coke in an electric furnace yields phosphorus, calcium silicate, and carbon monoxide. Phosphorus distills off at high furnace temperatures and is condensed to the solid state.

The only problem is first, I don't know where Calcium Phophate can be found or obtained and second, how high the temperature of the furnace needs to be for it to react properly. I am not sure on the exact way of doing this, this is just how to do it.

[knowledgehungry]

You could make Calcium phosphate by reacting phosphoric acid with a Calcium salt. I think there are some problems with attempting that method, it would require very high temperatures IMHO.

[vulture]

Atleast 1100C IIRC and I wouldn't want to work with gaseous phosphorus at 1100C unless in a 100% inert atmosphere!

[klassasin]

You would only do it if you had a death wish.

[vulture]

Polverone has covered the subject of phosphorous preparation quite nicely on sciencemadness and this board too.

There's also a thread somewhere about building furnaces that will achieve high enough temperatures.

[klassasin]

I have no problem with a furnace. I already built one which can get hot enough. Calcium Phosphate rock is the problem

[kingspaz]

could calcium phosphate not be made with phosphoric acid and CaO?

[klassasin]

It probably could, I am just wondering if there there is a way to get Calcium Phosphate besides that way.

[vulture]

Because phosphoric acid is a tribasic acid, the second and last proton do not dissociate very well. This means that when using concentrated H3PO4 you will mainly get Ca(H2PO4)2 and CaHPO4.
So a fairly diluted solution is the way to go.

[zeocrash]

i dont believe that you specifically need calcium phosphate. won't any phosphate do.
Bone ash is a good source of calcium IIRC
so get your ass down to your local KFC and get yourself some chicken bones to immolate

[klassasin]

Hmmm, chicken bones...

[knowledgehungry]

could calcium phosphate not be made with phosphoric acid and CaO? I already suggested that but i never get any credit :( .

[klassasin]

I am sorry. I credit you for that then.

[jfk]

you can buy (or steal) calcium phosphate from any fertiliser supplier in NZ........a few days ago i saw 500kg bags of it when i was there.
\

you could try it in a nitrogen atmosphere, if you were insane

or you could find an company that does this, find their site and raid it.

[Hang-Man]

Phosphorus was first isolated by Henning Brandt at Hamburg in 1669 when he evaporated urine and heated the residue until it was re hot, this released phosphorus vapor, which he collected by condensing in water. (He tried to keep it a secret thinking he discovered the "philosophers stone") It was not until it was realized that bone was made of calcium phosphate, and that it too could be used to make phosphorus, that it became widely available. Most was manufactured by heating phosphoric acid (produced by dissolving bone in H2SO4) with charcoal. By the end of the century phosphorus was being extracted from mineral phosphates by heating it with coke in an electric furnace.

(Coke= a form of carbon made by the destructive distillation of coal. Coke is used for blast-furnaces and other metallurgical and chemical process requiring a source of carbon. Low grade cokes, made by heating the coal at a lower temp, are used as smokeless flues for domestic heating.)

source: “Natures Building Blocks”- John Emsley
“Oxford Dictionary of Chemistry”

[Bert]

You can buy rock phosphate as fertilizer here (http://www.gardeniq.com/product.cfm?Category=GP&ItemId=39&CFID=89801&CFTOKEN=99433704) The technology to safely produce elemental phosphorous from it would be a bit complex for most 15 year olds to assemble and too large to hide under their beds- Phosphorous is nasty stuff to handle, it's been banned in US commercial fireworks for many years with good reason. The one accepted use is in sensitizing chlorate compositions in matches and igniters for flares and such. Of course, it's very popular with meth manufacturers...

[Marvin]

Anyone attempting to make P will not want rock phosphate unless they have an industrial size arc furnace. The most likley method to work well at home would be the calcium dihydrogen phosphate method using a rhetort of clay/iron/steel etc in a decent furnace, maybe charcol or coke fired. The fertliser needed is 'triple superphosphate', though I dont know where its sold. Double superphosphate, sold commonly, would produce huge problems if attempted.

In fact the Brandt method of making it was much much more involved, using a series of putrifactions and distillations where only a very small fraction of the combined phosphorous in urine ended up in the final oil that was destructivly distilled to produce phosphorous itself.

[megalomania]

Triple superphosphate is sold as a fertilizer just about everywhere garden fertilizer is sold. The method using carbon requires higher temperatures, even though it is more efficient. This may be good for industry, but bad for those of us who have a hard time getting high heat.