Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
Author: Subject: White Phosphorus Synthesis
FireFly
Harmless
*




Posts: 8
Registered: 2-2-2003
Location: WV
Member Is Offline

Mood: No Mood

[*] posted on 19-2-2003 at 21:14
White Phosphorus Synthesis


Does anyone know of a synthesis for White Phosphorus?
Thanks,
N.P.
View user's profile View All Posts By User
Polverone
Now celebrating 21 years of madness
*********




Posts: 3186
Registered: 19-5-2002
Location: The Sunny Pacific Northwest
Member Is Offline

Mood: Waiting for spring

[*] posted on 19-2-2003 at 23:42


There is already a long thread "preparation of elemental phosphorus" that you could have found with the search function.

http://www.sciencemadness.org/talk/viewthread.php?tid=65

Here's the executive summary: preparing white phosphorus is straightforward, at least in theory, if you can achieve and sustain high temperatures (> 1000 C) for several hours. There are other methods that promise to work at somewhat lower temperatures. The most promising of these methods use aluminum to reduce various phosphorus compounds. Nobody who visits this forum has yet procured useful (greater than a few centigrams) quantities of phosphorus by any of these methods, though there have been some promising preliminary experiments with aluminum. I have never seen anyone on Usenet or other web forums claim to produce usable quantities of phosphorus by any of these methods either.

As I said, the chemistry is straightforward, but most people who have attempted have been using carbon as the reducing agent, a la historical methods (ordinary furnace) or modern industrial methods (arc furnace). These methods require too much engineering and/or Open Space Without Neighbors to be practical for most amateurs. I think the aluminum route will eventually be made practical. The Great White Phosphorus Bear is in our sights. He's so close I can hear him breathing sometimes. If I had more spare time I might be taking more shots at him, and eventually bag him like I did the Cyanide Panther. Certainly great prestige within the hobby chemist community (whatever that's worth) awaits the first person who can show they've made phosphorus and give a writeup for others to follow. In certain circles accompanying instructions for conversion of the white allotrope to red would also be joyfully received, but that is a fairly minor challenge compared to getting the elemental P to begin with.
View user's profile Visit user's homepage View All Posts By User
PoDuck
Harmless
*




Posts: 8
Registered: 17-2-2003
Member Is Offline

Mood: No Mood

[*] posted on 20-2-2003 at 03:15


So, it looks to me that the biggest inhibitor of getting phosphorus using the old method is the heat. I don't understand why it wouldn't be possible to get temperatures high enough to produce the right effect. In actuality, I don't understand why the furnace itself has to be air tight at all.

Would it not be possible to use the design of the home built foundry and then create a ceramic crucible that has the ability to direct the gas put out by it through the chimney of the furnace. Then you could get extremely high tempuratures without worrying about the furnace being air tight, and you could build it for less than $50.

Something like this:



The crucible and it's upside down funnel top need to be made of some sort of ceramic. Steel may also work if you could be sure you don't get the temperature too high, the ceramic would be easier to get a decent seal on though. There would be some thermal resistant cord placed around the circumference of both the top and bottom sections of the crucible section. It won't be air tight, but it should create enough pressure to force the air to go through the copper tubing instead. You would put some copper tubing in the end of the funnel and run it to a container filled with water.

I have built a foundry before, and I know that with the right design for the burner, you can get propane to tempuratures near this. If you were to use a different type of gas, or be able to insert oxygen into the process, you should have no problems melting a steel crucible, much less heating phosphorus to the right tempurature.
View user's profile View All Posts By User

  Go To Top