Sciencemadness Discussion Board

Preparation of elemental phosphorus

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watson.fawkes - 24-9-2010 at 14:02

Quote: Originally posted by blogfast25  
Silicates, like glass, tend to have lower melting points than actual silica...
Silica around alkali and alkali earth oxides is going to form a glass and lower the melting point. It's entirely possible the the main benefit of introducing silica is to get the reaction into liquid phase much more readily. If that's so, an easy way to get a glass going to throw in some waste glass. It's standard procedure when doing custom melts of glass to start with some melted glass whose proportion can be modified; it gets the melt going much quicker and saves energy cost. Seems plausible that the same principle would apply if indeed molten glass is in fact the reaction medium here.

Rogeryermaw - 24-9-2010 at 16:03

after another run with the addition of NaCl i am completely convinced that it helps reduce the viscosity of the melt. i only used about 6-7% the weight of the reactants and i would say all P4 had finished bubbling out in about half the time as usual. as usual blogfast, your science is strong! i did take video and several snaps which i will make available after editing.

ok the video is available for those of you i sent the link to. i'm not sure who all should get it since you tube said i can only send it to 25 people.

i need your youtube screen name to give access to the videos.
[Edited on 25-9-2010 by Rogeryermaw]

[Edited on 25-9-2010 by Rogeryermaw]

blogfast25 - 26-9-2010 at 08:29

Quote: Originally posted by Rogeryermaw  
as usual blogfast, your science is strong!

i need your youtube screen name to give access to the videos.
[Edited on 25-9-2010 by Rogeryermaw]

[Edited on 25-9-2010 by Rogeryermaw]


Thanks, Roger, but far too much praise: people like me that have messed around with thermites and other metallurgical reactions understand the importance of melt viscosity reducers, usually CaF2. In those, 'fluxing' is usually the difference between failure and success...

But for your, lower temperature, reactions the lower melting, more readily available NaCl may just have been the ticket... Just getting a bit of melt going may lead to the reaction starting earlier and thus also finishing earlier...

And as Watson noted earlier, the silica may also contribute...

Re. your earlier comment:

Quote: Originally posted by Rogeryermaw  
this thought just occurred to me. when word gets out that P4 can be produced this way (mostly applicable to u.s. experimenters) NaPO3 may be as hard to get as P4.

[Edited on 24-9-2010 by Rogeryermaw]


If the worst came to the worst, sodium metaphoshate is easily synthesised. As long as we have access to phoshate, we have access to metaphosphate and as long as we have access to good old bones, we have access to phosphate. No worries, really!

[Edited on 26-9-2010 by blogfast25]

[Edited on 26-9-2010 by blogfast25]

Magpie - 26-9-2010 at 09:07

Quote: Originally posted by blogfast25  


As long as we have access to phoshate, we have access to metaphosphate and as long as we have access to good old bones, we have access to phosphate. No worries, really!


This brings to mind a rare but brilliant satire by garage chemist:

"Another material worth banning: Bones. Everyone who reads up on phosphorus production will find out that animal bones once were the principal raw material for it.
No more chicken wings at burger king, only boneless steaks and chicken filet, no whole turkey, etc...
Possession of a dead animal containing bones is only legal for registered and licensed butchers, every other person will be charged with unlawful possession of a drug precursor."

blogfast25 - 26-9-2010 at 09:48

@Magpie:

All this could end up increasing the murder rate. I'd start an illegal 'bone export business' now, get in from the ground up, you know? Early bird catches the bone? ;-)

Magpie - 26-9-2010 at 14:59

I'm not sure if Roger agrees with this but I have the impression that using the NaCl flux is an important breakthrough in P production home technology. When I did my limited experimentation using Al/NaPO3/SiO2 the voluminous foam generated looked like it could be a real problem. Also, any method for getting the reactants into a liquid state at the lowest possible temperature sounds highly advantageous.

We should remember that the key to Charles Hall's breakthrough discovery of how to electrolytically produce aluminum was his use of cryolite (Na3AlF6), a liquid producing flux for the Al2O3 ore.

Possibly use of other fluxes in Roger's technology could prove advantageous. Specifically I'm thining of CaF2 and cryolite. CaF2 is readily available from pottery supplies distributors. Cryolite may be available there too. Also there are other fluxes, as any good book on pottery will show.

I would experiment with CaF2 in my ceramic tubes if I wasn't concerned that it would eat a hole right through them.

Rogeryermaw - 26-9-2010 at 15:05

what i have noticed about the use of NaCl as a flux is that it seems to reduce the viscosity of the melt and therefore allows the P4 vapor to escape more easily thus reducing the necessary burn time in the furnace. cut my time in half at least.

Magpie - 26-9-2010 at 16:39

Quote: Originally posted by Rogeryermaw  
what i have noticed about the use of NaCl as a flux is that it seems to reduce the viscosity of the melt and therefore allows the P4 vapor to escape more easily thus reducing the necessary burn time in the furnace. cut my time in half at least.


Yes! A viscosity reducer. That makes perfect sense. By reducing the viscosity the formation of foam is reduced, or eliminated. As, you say it also allows the P4 to escape easier.

By eliminating the foam it should be possible for me to increase the charge size without plugging the outlet of the retort.

blogfast25 - 27-9-2010 at 08:20

Quote: Originally posted by Magpie  


We should remember that the key to Charles Hall's breakthrough discovery of how to electrolytically produce aluminum was his use of cryolite (Na3AlF6), a liquid producing flux for the Al2O3 ore.

Possibly use of other fluxes in Roger's technology could prove advantageous. Specifically I'm thining of CaF2 and cryolite. CaF2 is readily available from pottery supplies distributors. Cryolite may be available there too. Also there are other fluxes, as any good book on pottery will show.

I would experiment with CaF2 in my ceramic tubes if I wasn't concerned that it would eat a hole right through them.


The cryolite in Al production has a slightlly different function: the electrolyte bath is a eutectic mix of Al2O3 and Na3AlF3 with a much lower melting point than Al2O3 (2054 C !!). Without the cryolite the Hall-Heroult process would basically have to run at above 2054 C. Now it runs at about 700 C (off the top of my head).

CaF2 (fluorite) would be no use in the phosphate reaction because it's MP is too high (about 1500 C) and it would either not really melt or not be very low in viscosity. NaCl is probably ideal...

But it is widely used in aluminothermy ('thermite' in common language) where to allow separation between the slag (contaminated alumina) and the molten metal you need to reach the melting point of both the metal and the slag (whichever is the highest). Adding CaF2 which melts well below the 2054 C MP of alumina much reduces the viscosity of the melt and so promotes the metal (which is insoluble in the alumina) to coalesce out and collect in a molten puddle at the bottom of the melt. There isn't a metal that I have produced using aluminothermy (Cu, Fe, Cr, V, Mn, Ti, Nb, Si, FeTi, FeV, FeSi) that didn't need a good dollop of CaF2 in the formulation to actually obtain valuable lump metal and not just fireworks...


[Edited on 27-9-2010 by blogfast25]

blogfast25 - 27-9-2010 at 08:35

Roger, I watched the vids with great interest, thanks for putting them up.

One possible improvement, re the air flow regulation. 'On - off' works fine of course but here's a little trick I use for a very small lump charcoal furnace which is aired with an inverted Hoover. That too blows far too much air, so I cut it down to a continuous regulator as follows. The tuyere (as it is known in the lingo of the furnacistos) is the pipe running into the furnace, connected to the blower. I cut it about three feet away from the entry into the furnace and fitted a funnel onto it at the end facing away from the furnace. Now I simply direct the blower onto the funnel and by adjusting the distance between the blower outlet and the tuyere funnel I can regulate the airflow like the best up there. Simple but effective!

Finally, I'm not sure why you want to keep the vids private. P4 has no major uses in bomb making or drug making. Why not make your design available commercially, either as blueprints or as actual pre-a-porter reactors? Land of the Free, no?

Rogeryermaw - 27-9-2010 at 08:49

as for the blower, one of these days i was planning on putting a dimmer switch in line to control the motor voltage. since it is a straight wired motor i don't think the changes in voltage will hurt it. or i have also considered using the engines from one of my ducted fan model airplanes. i do like your funnel idea...would be cheaper and i already have the parts to make that happen!

as to making the vids public, here in the states methamphetamine production is out of hand and one of the ways they make it is by reduction of ephedrine by hydriotic acid produced in situ by reacting iodine with red phosphorus. that's whats holding me back from releasing this to the the world. i do agree with you that withholding useful info is a sickening practice but i'll be damned before i will give those stinkin' meth punks another way to ruin chemistry for the rest of us.

[Edited on 27-9-2010 by Rogeryermaw]

Magpie - 27-9-2010 at 09:32

@blogfast
I do not doubt your expertise and experience in the area of using fluxes, etc, and do realize that these minor additives may very well serve different functions depending on the situation at hand. But I was under the impression that many fluxes used for ceramic work are successful because they lower the melting point of both the substrate and the flux, the ultimate being a eutectic composition.

I have been reading some about glass making. One problem they have to deal with is the inclusion of gas bubbles. To eliminate this they use fining agents to reduce the melt viscosity. This facilitates the release of the gas bubbles. Among the fining agents mentioned the most user friendly appeared to be sodium chloride and sodium sulfate. Although I believe the sulfate could release SO2 gas in a reducing environment.

So, as you say, NaCl may be optimum for the case at hand.

@Roger
I wanted to add my twist on air flow regulation: Place a tee in your airline, using the straight section for the airflow to the furnace. On the branch leg place a valve, ideally a globe type for finer regulation, but a ball valve would likely suffice. The airflow then is easily controlled by how much you spill through the valve on the tee.





[Edited on 27-9-2010 by Magpie]

blogfast25 - 27-9-2010 at 09:39

Quote: Originally posted by Magpie  
But I was under the impression that many fluxes used for ceramic work are successful because they lower the melting point of both the substrate and the flux, the ultimate being a eutectic composition.




Yes, that's correct. Even cryolite is occasionally used in glazes and some potters stock it.

blogfast25 - 27-9-2010 at 09:41

@Roger:

That's fair dos I guess. Here in Europe we can buy powdered red P but I guess we don't have crystal meth problem, or at least not as large...

Rogeryermaw - 27-9-2010 at 10:06

i will say this though. i trust your judgment, blogfast, and you have the info to watch the vids anytime you want. you can share it with whom you see fit. i trust your motives and don't think you will misuse it. same goes for all of you i have shared this with. i would like to see responsible home chemists have access to P4. as Polverone put it, "Phosphorus and its compounds are invaluable reagents for a variety of laboratory procedures, and it's also just plain nifty."

Rogeryermaw - 27-9-2010 at 10:10

Quote: Originally posted by Magpie  




@Roger
I wanted to add my twist on air flow regulation: Place a tee in your airline, using the straight section for the airflow to the furnace. On the branch leg place a valve, ideally a globe type for finer regulation, but a ball valve would likely suffice. The airflow then is easily controlled by how much you spill through the valve on the tee.





[Edited on 27-9-2010 by Magpie]


not bad Magpie! much like the wastegate on a turbocharger!

peach - 27-9-2010 at 16:17

Quote: Originally posted by Rogeryermaw  

one of the ways they make it
[Edited on 27-9-2010 by Rogeryermaw]


One of the ways? It seems to be the ONLY way most of them know. :D That recipe is over a century old.

I don't mind if drugs are Hofmann's problem child, but I do mind when that child cuts the phone off harvesting the copper. If you hear a can of 9% larger fall from about telephone pole height, that's more likely the lesser spotted, reclusive heroin addict out foraging for berries; addict slang for scrap metal.

With all this furnace talk, have you guys read Dave Gingery's "How to build a gas fired furnace"?

I bought it when I was about 14, along with "How to build your own lathe".

The gas fired furnace one, he tells you all about making your own refractory from firebricks, clay and other things. There's a blue print for a working out the book furnace with a removable lid, and instructions on how to make the formers and ram the refractory. As well as details, drawings and measurements for building a centrifugal blower and some rough information on green sand casting.

The blower, you may as well buy one or scrounge one from the tip (modern combi boilers have a £100+ high heat one in the top, and the boilers end up at the metal scrap yards; ask for 'berries' and remember to say 'berry merry munch' when the deal is done).

The furnace dimensions and details are easily changeable. If you google for anything like DIY / Furnace / Gas / Dave Gingery / Gingery you'll find tons of pages. And there's the hobbicast group on yahoo groups.

I just thought the design could be easily manipulated to make a more permanent retort furnace.

I've read the book tons already and it's just been sat on the shelf for aaaaaaages. As a thank you for making the video and letting me watch it, you can have my copies for free if you like Roger.

I just found my refractory bricks and an empty propane can.

Rogeryermaw - 27-9-2010 at 16:29

[rquote=188511&tid=65&author=peach
One of the ways? It seems to be the ONLY way most of them know. :D That recipe is over a century old.

I don't mind if drugs are Hofmann's problem child, but I do mind when that child cuts the phone off harvesting the copper. If you hear a can of 9% larger fall from about telephone pole height, that's more likely the lesser spotted, reclusive heroin addict out foraging for berries; addict slang for scrap metal.

[/rquote]

man that is more real than you know. there was a trolley system in downtown that has been shut down because the wiring has been ripped out twice and on the news(when i was working on the spawar contract building security equpiment for national guard aviation bases) in hawaii about the (i think it was the H3 highway) new highway construction where the ice heads stole the wiring for the new lighting system along the highway...they have no scruples at all!

peach - 27-9-2010 at 16:34

They are funny guys. And truly dedicated to recycling, sometimes before it's ever been used for the intended purpose they're that eager.

I saw two guys in Scotland at one point pulling up all the tiles in an abandoned house. The police turned up and one of them refused to be arrested or get in the car until he'd got his sandwich and can of beer back in his hands. Then he shut up and jumped in the car. Simple folk. All for £40 and a few more hours dribbling in a chair, numb to the world. Poor boys.

"If it's nailed down, they'll probably steal the nails as well"

[Edited on 28-9-2010 by peach]

blogfast25 - 29-9-2010 at 12:53

@Roger:

Any chance of a P4 yield estimation? You know, P out divided P in x 100?

Rogeryermaw - 29-9-2010 at 14:26

well at roughly 5.1 grams of phosphorus in 102 grams of 6(NaPO3) with a return of at least 4 grams per run (since we scaled it up) it's close to 78%. there must be losses to atmosphere etc but the return is fairly high.

on the second attempt with the scaled up design the haul looked physically larger but i did not weigh it.

[Edited on 29-9-2010 by Rogeryermaw]

Strepta - 29-9-2010 at 15:52

@Rogeryermaw:

Roger, what was the the mass (in grams) of the NaPO3 you used in the experiment which yielded 4 g of P? If you used a mole (102 grams) there would be about 31 grams of P available.

peach - 29-9-2010 at 16:31

102 grams is 0.166 moles of the hexa phosphate (611.7g/mol). 6 phosphors in each mole, so it'd yield 0.996 moles of P.

He's yielding P4, making that 0.249 moles of that allotrope. At 123.88g/m for P4, that's 30.8g (matches with above 0.996 of P). And a yield of around 13%. Unless my 1.30am brain has gone dead on me and I've made a mistake.

13% still beats 0%, particularly for such a tricky element. Add to that, he's only just got the thing going! Extra roasting may yield more.

Quote:
In 1669, German alchemist Hennig Brand attempted to create the philosopher's stone from his urine, and in the process he produced a white material that glowed in the dark.

^^^^^^^^^^:D^^^^^^^^^^^^

That reminds me of when we made yogurt in Chemistry and someone astutely asked, "Why was he eating the white curd on a cow's tits in the first place?"

[Edited on 30-9-2010 by peach]

Rogeryermaw - 29-9-2010 at 16:56

wow. you are correct sir. thank you for making me check my math! i guess that actually works out to about 13%. now i have to run it again and see what the yield turns out to be. if you look you'll see where i goofed up. i calculated for 1/6th mole of HEXA metaphosphate and translated that to 1/6th mole of phosphorus. 1 sixth hexa is the same as 1 mole meta in this case so at 1 sixth mole times 6 atoms phosphorus per mole = 1 mole phosphorus. so thank you for catching that! and at 4+ grams out per 31 grams in yield is roughly 13%. again as i said on the most recent attempt the yield looked to have larger physical volume but i did not weigh since i was working on the video. so yield is not spectacular but since it yields something we can't buy in the states any at all is better than what i started with.

Strepta - 29-9-2010 at 17:00

@Rogeryermaw:

Roger, you stated earlier that the NaCl reduced the "burn time" in your furnace by about half. How did you determine that the reaction was complete? Are you listening for the gas bubbles in the receiver?

Rogeryermaw - 29-9-2010 at 17:37

Quote: Originally posted by Strepta  
@Rogeryermaw:

Roger, you stated earlier that the NaCl reduced the "burn time" in your furnace by about half. How did you determine that the reaction was complete? Are you listening for the gas bubbles in the receiver?


yes that and the escape of vapors from the collector. you know, i haven't show this yet but i have run the reaction at night as well and, as far as using the vapor as a guide, as i mentioned in the video about the lid notched to fit the pipe coming out of the furnace, if you don't bury it completely, you can see the bluish, greenish, you know i'm not sure how i would describe the color, glow of a small amount of P4 vapor escaping around the pipe...perhaps if i can devise a way to control this it will increase yield.

peach - 29-9-2010 at 21:09

Don't stress it roger, it's VERY easy to make mistakes with the numbers.

I wouldn't feel down about the yield either, I'm sure it'll pick up with a bit more R&D. I'll try to get involved.

Rogeryermaw - 29-9-2010 at 21:34

aww hell i'm not down at all! the fact that it works at all is worth a lot as far as i'm concerned. i've been watching your videos quite a bit and your work is impressive to say the least!

blogfast25 - 30-9-2010 at 05:52

Forget the hexas for a minute, take 101.961 as the MW for NaPO3 and 30.97 as the atomic weight of P.

Yield = Pout / Pin x 100%

Pout = weight P (g)

Pin = weight NaPO3 (g) / 101.961 x 30.97

Yield = 101.961 / 30.97 x (weight P / weight NaPO3) x 100
= 329 x (weight P / weight NaPO3) (in %)

... which works out as 13%.

That's quite disappointing of course. I wonder why the yield is so low...

Rogeryermaw - 30-9-2010 at 08:33

it was the whole hexa thing that brought about my miscalculation. if you take that 13% and multiply it by 6 you get my original estimate of 78%. ya the yield is low i agree. the process, i'm sure, needs streamlining. perhaps there is a better flux i can use or a tweaking of the amounts of this or that reactant. the process is in its infancy and i'm sure if we put our collective experience and innovation into it we can get it better. even still, with how cheap the reactants in this synthesis are, i'm thrilled to get phosphorus at all! may not be ideal but it's better than the P4 i had before(none).

a few things that come to mind are the reactor for one...how much may still be trapped inside? the collection method is losing quite a bit to atmosphere as i stated already since i am counting on vapors condensing in such a short distance and with minimal exposure to the water since we feared the possibility of a steam explosion. there are certainly many factors to be improved. given time and trials the numbers can certainly be improved upon.

i should have weighed the product from the last run. it is my belief that my percentage of theoretical would be closer to 19-20%

blogfast25 - 30-9-2010 at 12:20

Quote: Originally posted by Rogeryermaw  


a few things that come to mind are the reactor for one...how much may still be trapped inside? the collection method is losing quite a bit to atmosphere as i stated already since i am counting on vapors condensing in such a short distance and with minimal exposure to the water since we feared the possibility of a steam explosion. there are certainly many factors to be improved. given time and trials the numbers can certainly be improved upon.

i should have weighed the product from the last run. it is my belief that my percentage of theoretical would be closer to 19-20%


I think there must be considerable amounts of reaction product phosphorus still locked into the slag. Not sure how one would would go about proving that though...

If there's unreacted NaPO3 in the slag, grinding and leaching with water should show that up...

Of course it's impossible to gauge how much P you're losing at the collection point...

peach - 30-9-2010 at 13:23

I agree with bloggerman, and was about to suggest that before reading his reply. If the bubbling stops, it signals the end; theoretically. But there's a good chance some of it is still hiding in the actual melt it's self. Quite a lot from those numbers.

On the next run, I'd look for phosphorus trying to escape the collector; test for it, don't sniff :D. If any significant amount is found, you could try cooling the collector, like in the metalresearcher sodium thread.

If no real value is escaping, it's got to be in the melt still. Have you tried roasting for any period of time after the bubbling stops? That's a bit of a weak suggestion.

It may need more heat for a higher temperature, or something to push it to the collector, the same way a Dean-Stark needs the water gone to drive it through to the right side of the equation; this may need more heat to drive it out of the melt and to the collector (?it's absorbing in the melt? Hydrogen chloride absorbs nicely in water to hydrochloric, but then comes back out at room temperature for strong acid and all of it is out once the water is gone or the temperature is raised).

From all the gas work I've done, I do know that you have to massively bias the amount of gas you're using over the theoretical for it to absorb properly. They just don't function like liquid / liquid reactions in terms of the theory, unless they're run INCREDIBLY slow and gently, with frits and such. Maybe you could add a frit of metal sponge to the end of the pipe. I know where you can get some aluminium sponge for free. But, as I've learnt with all my gas wash bottles, that's not always a good thing. As they tend to clog. And clogging, mid anhydrous, pressure producing work involving the reactive gases is not good in anyway!

Before even trying the flame method, I'm already wondering about using electrodes and arc welders.

Again, forget worrying about 13%. A total organic synthesis can yield 1% and below after a huge amount of work by genuinely the best chemists around. It doesn't matter when the things going in and process are cheaper than some beer. And when it's only the first few tries.

{EDIT} I just had A THOUGHT! When I'm trying to truly capture a nasty gas from a reaction, like hydrogen chloride, I don't just use water. I use a base in the wash to salt the gas out; as the acidic gas will neutralize with the base. It works so well I can't smell / feel anything, even with my nose against the exhaust. If absorption was a problem at the collector, maybe you could use something similar. Make it faaaar more favourable, energetically, for it to stay in that collector, but in a form that can be easily extracted afterwards. This same trick works for horrendously toxic materials, and it's how they do things industrially where fume hoods don't mean anything. {that EDIT tag seriously annoys me, yeah one, fine. But having to constantly edit an edit tag for missed spaces and spellings....}

To liven things up, here's a funny video for all you welding and fire fans (me included);
<object width="660" height="525"><param name="movie" value="http://www.youtube.com/v/G6Uxh-xtU-g?fs=1&amp;hl=en_GB&amp;color1=0x5d1719&amp;color2=0xcd311b&amp;border=1"></param>& lt;param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/G6Uxh-xtU-g?fs=1&amp;hl=en_GB&amp;color1=0x5d1719&amp;color2=0xcd311b&amp;border=1" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="660" height="525"></embed></object>

You think that's enough juice? It's enough that they have to talk with the grid before building and starting one of these up. It's a good 1% of what the fission stations can actually output, flickering on and off as the arc makes and breaks. Can't get enough of the sparks, fire and grid hum. I like the way they've got some pop music on in the quiet control room, watching it.
<object width="660" height="525"><param name="movie" value="http://www.youtube.com/v/ijWwfcw0FOo?fs=1&amp;hl=en_GB&amp;color1=0x5d1719&amp;color2=0xcd311b&amp;border=1"></param>& lt;param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/ijWwfcw0FOo?fs=1&amp;hl=en_GB&amp;color1=0x5d1719&amp;color2=0xcd311b&amp;border=1" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="660" height="525"></embed></object>

[Edited on 30-9-2010 by peach]

Rogeryermaw - 30-9-2010 at 13:47

Quote: Originally posted by peach  

On the next run, I'd look for phosphorus trying to escape the collector. If any significant amount is found, you could try cooling the collector, like in the metalresearcher sodium thread.
[Edited on 30-9-2010 by peach]


my thought was to eliminate things one by one. as i said before, there is definitely some loss to atmosphere. visualize this: at the end of the pipe the P(g) is at least 280 Celsius(b.p. of P)when it has to condense to liquid in less than an inch depth of water(as deep as i have submerged the pipe yet. will try deeper and with cooler water). to cool such hot gas to 44Celcius(m.p. of P) is going to be quite less than 100% efficient at this depth.

my thinking is to dig the collector deeper and use a longer down pipe with cooler water. i'll give this a try and we can go from there. when i do run it i will be sure to weigh my product and post the analysis of any improvement in yield.

peach - 30-9-2010 at 13:57

Yep, dead on, longer, taller collector and cool it some way if you can, keeping the condenser cold and the pipe warm.

The step from 280 to 44 is a big one to make to achieve a gas -> liquid / solid theoretical yield! Before it ever collects, it has to loose a lot of heat, quickly. If the collector is hot (warm), it'll try to get through. Same with buchi's. Boiling off a volatile, connect them to a rotary and hey presto! You have solvent in the pump, even with a dry ice finger in the way. Doesn't have long enough or a big enough gradient to cool through.

Heat capacities are something worth wiki'ing here. Some things at 1000C cool to 0C with next to no effort. Others, like water, need to dump a huge amount of energy in the process.

Those state changes soak up / release energy, orders of magnitude more than liquid / liquid chemistry.

Theoretically, I should be able to condense numerous volatiles under vacuum with ice in my condenser loop. In practice, it's a harder than that.

[Edited on 30-9-2010 by peach]

aax - 30-9-2010 at 15:01

The bad guys don't need your phosphorus... I don't need you to post a video. A video would make it easier but it is not nessesary.

Rogeryermaw - 30-9-2010 at 15:14

good then slag off ya smart anus

produce a better attitude and make some contributions here and i will be much more willing to share. phosphorus is poisonous and lethal in less than 50 milligram quantities. it could kill you with the tiny bit stuck under your fingernail from handling it without protection. you haven't shown anyone here that you have the equipment or safety consciousness to handle chemicals with high toxicity.

and no one said the "bad guys" need it. they have their own means but you are obviously fishing for something...

[Edited on 30-9-2010 by Rogeryermaw]

Strepta - 30-9-2010 at 15:45

Roger-- an important first step is to determine the mass of the post reaction residuals and compare this with the mass of your initial charge. This difference vs what you actually collect will give you an indication of your collection efficiency. This is most easily done by weighing the entire apparatus pre and post-reaction. You need to do this with sufficient resolution to be able to "see" differences of a gram or two at the levels you are experimenting with. Can you do that with your reactor and pipe or will it be too massive for your scale? If it is too massive, you will need to carefully clean out and weigh all post reaction slag and unreacted chems and compare with the initial charge-- this is more of a PITA but ultimately helpful in determining loss mechanisms.

Rogeryermaw - 30-9-2010 at 16:01

ya my scale only does 600 grams unfortunately but (and you aint kiddin' pain i.t.a.) weighing the reaction mass is possible with the can type i used. it can be cut and peeled off the mass of slag without too much hassle. when a heavier vessel is used it may prove more challenging. i think another run in more controlled circumstances is called for with more stringent data records.

blogfast25 - 1-10-2010 at 08:48

Quote: Originally posted by Rogeryermaw  
it can be cut and peeled off the mass of slag without too much hassle. when a heavier vessel is used it may prove more challenging. i think another run in more controlled circumstances is called for with more stringent data records.


Have you actually had a close look at the slag inside the can? You might actually find quite some P near the exhaust... Just a thought...

Rogeryermaw - 1-10-2010 at 10:51

yes sir i have. i reuse the 3/4 and 1/2 inch piping on each reactor. there is little if anything to get from it. however under the conditions i've been using it would likely burn away trying to recover it. from my observations the bulk of the P is still in a gaseous state until it hits the water at which point some is recovered and some is lost, the ratio of which is still a mystery to me. it is my (quite unconfirmed) opinion that there may still be some in the melt, some of the chemicals are not reacting and there are losses to atmosphere. keep those thoughts coming though because they are what have been pushing me in the right direction.

it also occurs to me that some of the reaction may not be as straightforward as i have been assuming. there may be significant losses to the formation of metal-phosphides as part of the slag. that, to me, would be an acceptable loss since it is the use of a reactive metal that has brought the whole concept of phosphorus production within the reach of home experimenters. i wonder if using the excess aluminum is contributing to this...

upon further study this seems very likely since AlP is sold as rodenticide under trade names: Celphos, Fumitoxin, Phostoxin, and Quick Phos which are produced by igniting a mixture of phosphorus and aluminum.

[Edited on 1-10-2010 by Rogeryermaw]

[Edited on 1-10-2010 by Rogeryermaw]

[Edited on 1-10-2010 by Rogeryermaw]

blogfast25 - 1-10-2010 at 11:53

Quote: Originally posted by Rogeryermaw  

it also occurs to me that some of the reaction may not be as straightforward as i have been assuming. there may be significant losses to the formation of metal-phosphides as part of the slag. that, to me, would be an acceptable loss since it is the use of a reactive metal that has brought the whole concept of phosphorus production within the reach of home experimenters. i wonder if using the excess aluminum is contributing to this...

upon further study this seems very likely since AlP is sold as rodenticide under trade names: Celphos, Fumitoxin, Phostoxin, and Quick Phos which are produced by igniting a mixture of phosphorus and aluminum.



It's possible than AlP is formed, I didn't think of that. Whether or not AlP is formed in those conditions depends largely on the Heat of Formation of the AlP, because that's what affects the equilibria that I briefly described above.

But using an excess of Al would certainly favour it's formation. P is well known for its propensity to form compounds by direct union with other elements. So perhaps it's better to 'starve' the mixture of Al, i.e. 90% of stoichio, rather than 110%.

I doubt that even 100 % conversion of the excess Al to AlP would account for all the 'missing' P...

[Edited on 1-10-2010 by blogfast25]

Rogeryermaw - 1-10-2010 at 12:12

it also depends on how the reaction proceeds too. does all the P evolve then react with excess Al or do these reactions proceed simultaneously. in the first instance a stoich amount or less would be favorable. in the second instance it seems that both P and AlP would be formed regardless of quantity of Al. would be nice to have a way to analyze the slag but i don't think i want to toss it in water and see if it kills me(since metal phosphides release phosphine when wet). any other ideas for analysis? perhaps i could catch a mouse and put it in an aquarium then powder some of the slag, place it in the aquarium and wet it then cover the top(outside of course). homemade pesticide anyone? :D

you animal rights guys can piss off before posting. i live in the country and mice are a problem as it is.

[Edited on 1-10-2010 by Rogeryermaw]

peach - 1-10-2010 at 13:55

React it with water under a lid, pipe off any evolving gas, run it through a blow torch flame in another lid capable vessel and weigh for solid P.pentoxide? Not super safe, but seems the easiest. And you get some free garden fertilizer out of it.

Danger Roger, Danger!

Given the amount of what could be hiding in that melt, I would HIGHLY recommend you chip off a sample lump, weigh that, then do the test on a small chunk of it. As opposed to doing the whole melt. If the melt isn't homogeneous (e.g. if there's a distinct layer or clumping of something that looks different to the rest), you need to account for that.

A possible embodiment based on what you have / suggested. Smash up the melt lump sample, do the reaction in a pipe nipple etc, tube it off to said aquarium with a piece of glass over the top and the light blowtorch inside (you want the tube exiting right into the flame if possible, peak of the blue cone). The p.pent should coat the glass. Scrape it back off with a razor blade when you're sure it's finished, resist urge to do whole melt so you can measure it on the kitchen scales, buy $10, 0.01g, Made In China, pocket scale from eBay (checked 'em, they're less than 1% off a £3k, 0.1mg balance), weigh.

This is where googlemapping our rough locations and meeting up would be kick ass. If we were near by each other, I have all the gas handling glass and the balance. And I could find a use for some of that phosphine for doping my at home semiconductor attempts.

As if chemists didn't have enough problems, now PETA's gonna start bricking our windows and then running away (if they can get the energy together) to kill some more mycoprotein producers and vegetables.

PETA wrote to Timothy McVeigh whilst he was on death row, appealing for him to be fed a vegan diet to end the killing. Here's his reply (already posted it once, but love it), which I've not heard many others suggest and I couldn't put it any better myself;

Quote:
Truth is, I understand your cause - I've seen slaughter houses myself - but I still believe in reasonable taking and eating of game (as an outdoorsman and hunter)... I cannot sustain a prolonged intellectual debate on the subject as my time is short, but I'd suggest hitting Ted Kaczynski up for his opinions on the subject. [...] Where do you draw the line and what standard is used to define that line? Those that are in it for the health benefits accept poultry and fish as edible. Where do those opposed to suffering stand? (Ever see a fish struggling out of water?) What about grubs/worms/etc.? And finally, plants are alive too, they react to stimuli (including pain); have circulation systems, etc. So how about them?


[Edited on 1-10-2010 by peach]

Rogeryermaw - 1-10-2010 at 18:10

as unpopular as it may be, i will grub the hell out of a steak. i will eat any meat just about(except tube steak)and veggies are fair game too. the activists piss me off. when i was working in colorado (the aforementioned job i had doing security and networking installations in military facilities took me all over the country from florida to montana, from michigan to hawaii and several points in between. mentioned this to you peach as the time i was in colorado was the last time i actually visited with that good friend of mine) the guys that liked to ride the trails always told us horror stories about the "green gangs". they hated the guys who rode the trails saying they were hurting the environment so they would "spike" the trails to disable the 4 wheelers. however what they accomplished was attempted murder. people would fall off their machines and be badly injured. said machines would fall off cliff sides being destroyed leaking fuel and oil into the environment they were "saving". mindless freaks! i'm not saying i support wrecking the environment, i dispose of anything dangerous in legal manner but the green activists go too far. i'm american so let them try to put a brick in my window. i got something for 'em! if my dogs haven't killed them before they get close, here where i live, trespassers get shot.

i think this is a fine idea about weighing the P2O5 as a combustion product. weigh the mass i'm testing, weigh the water used, weigh the mass after testing and and P2O5 that may form should give us an idea where all the rest of the P is going.

got a link for the seller of that scale? love the mcveigh quote...guess were going to have to live on fungus!

blogfast25 - 2-10-2010 at 08:32

When I ran my 10 g (or so) NaPO3/Al/SiO2 reaction (stoichiometric ratio) in a 1 fl. oz steel tumbler (simply by heating it to red heat in open air), I obtained a typically black, foamy mass of slag with a slightly odd smell but definitely no phosphines developed. But during the reaction I clearly saw very visible green-yellow phosphorescence from liquid P, until the P caught fire and nice little yellow jets of burning P left white P2O5 smoke behind. I remember switching the heat off but it just kept going for a while... Strepta with his ceramic tube reaction didn't report any problems with phosphine from the slag either. I think we may be worrying a tad too much about AlP and phosphines...

Edit: similar reactions with quartz tubes were conducted both by Strepta and Magpie...

The reactions probably do run 'simultaneously' here, and the dissociation of P2O5 ---> 1/ P4 + 5/2 O2 is probably the rate-determining step, as it takes a lot of heat to get some dissociation going and thus that reaction is probably the slowest of them all.


The formed O2 would be scavenged by 2 Al + 3O2 ---> Al2O3 superfast because of the massive Heat of Formation of Al2O3.


[Edited on 2-10-2010 by blogfast25]

peach - 2-10-2010 at 08:50

These are the exact ones I have;

ONE!
TWO!
THREE!

HA, AH, AH, AH!



If you go on eBay and search for "0.01g" / "jewellery" / "jewelery" / "scales" a whole ton of them will turn up. A lot of them are probably from the same factory with the same circuit and weigh bridge in them. Those ones I bought are some of the cheapest on there.

You'll need to get a set to weigh the 10g results and definitely the oxide from a sample of the melt. It's not the RESOLUTION that matters, you don't need to know the 10g numbers to 0.00000001g, but the ACCURACY. Those digital kitchen scales could easily be off by a gram or two at 10g (see the graphs at the end).

Maybe I should buy a whole bunch of these things, produce curves for them on the 0.1mg balance and resell them so people can get cheap, accurate balances with known errors.

You shouldn't need to weigh the water, just the sample from the melt and the resulting oxide. I'm off to watch the UK fireworks championship, day two, so I can't find the numbers right now, but it could really do with working out a safe / measurable sample to use from the melt, assuming it's all hiding as AlP and will go to phosphine. E.g. not the entire melt, but enough that the oxide will show up as a solid number on one of those cheap scales.

I remembering reading, quite randomly whilst wandering around the library in my teens, a book on military warfare. Where they discuss how chemical weapons need their lethal doses multiply up by tens of thousands of times, or more, when dispersed into the air, because they'll dilute down so much before they ever touch someone. The way to test for the AlP safely would be to use a smaller sample and do it outside, downwind, as you're aware.

Graphs I will post up with more explanations at some point; click to get the full version (don't want to make the forum look all spazzed out posting them full size here)

This is my Made In China 0.01g scale (in red) and the digital 1g kitchen scale. The scales on the left and right are not the same. Notice that the;

a.) 'drug dealer' scale is almost always permanently biased to a give a positive result, don't tell them that :P
b.) error doesn't massively grow or shrink
c.) pattern of error isn't very predictable
d.) 1g kitchen scale is HORRIBLY inaccurate at low numbers
e.) error DOES shrink for the kitchen scales, considerably, and conveniently, as the 0.01g scale cuts off (you can get 100g versions of these 0.01g things, perfect combination according to this graph)
f.) there is quite clearly a periodic swing from positive to negative for the kitchen scales once the mass being weighed goes over 50 - 100g

Scale comparison

Here I'm measuring the mass of all the 20p's, I think, from a big jar of change. I've done it for 1, 2, 10, and 5s as well. Notice that the;

a.) mass of the coins 'on the street' seems biased towards being more than their minted mass. Meaning gunk is building up on their surface quicker than they're wearing down (oxides, salts, greases etc)
b.) it's swinging in a periodic way, up and down, every few years and the coins that are decades old have about the same error as those that are new. So the main error in mass is controlled by the minting accuracy, not handling. The sine wave is the mint tweaking the presses and changing the dies for the coins. Importantly, it's periodic and swinging by roughly the same amplitude, positive and negative.

Errors in coins mass

If I take a stack of ten or twenty coins, randomly out of the jar, the errors begin canceling each other. When I sum up all the errors, this happens...

The % to which I can predict the mass of the stack of coins drops waaaaay down; multiple readings and error canceling.

Some of the cells on here look a bit wonky, hence me not posting it as a final thing yet, I need to finish it off really.

Important numbers

If anyone in the US would like to send me a jar full of low value coins, I can do the same for the US. I'll need 10 - 30 of each value for it to give a good result. I also don't know if they'd vary much from state to state, or if it's all coming from roughly the same mint or at least others controlled to the same standards as each other. I expect it is, or coin operated machines wouldn't work.

What's good about using low value coins is the mint controls the main error, tightly. Everyone has access to it, even tramps. Best of all, the canceling works better the less effort you put into sorting the coins, it works best with an entirely random selection of dirty / shiny, uncleaned coins and from various, random dates.

[Edited on 2-10-2010 by peach]

Rogeryermaw - 2-10-2010 at 11:30

i will get to the more important numbers and testing soon but here is some preliminary data.



1.JPG - 68kB
the initial weight of the reactants was about 217g and post reaction almost 200g give or take (scale accuracy)


2.JPG - 71kB


3.JPG - 74kB
mass as removed from can (minor losses due to the brittle nature of the slag)


4.JPG - 75kB
appearance of the inside. note the gas pockets. smelled terribly of phosphorus when broken open(wasn't trying to sniff it but couldn't help catching small whiff as it was very strong.



5.JPG - 64kB 6.JPG - 64kB
prepping a small piece to test for formation of PH3.
sorry i did not snap the process as i was nervous enough about TRYING to produce something deadly. was hard to tell for sure but i wet the ground mass in a pickle jar and placed a propane torch over the top. the water appeared to cloud during this but i'm not sure if that indicates absorption of P2O5. i did, however note greenish yellow deposits that fit the physical description of AlP.

based on the weights the reaction mass lost 17(ish) grams leaving 10-12 grams to account for after subtracting the estimated weight of phosphorus collected.

[Edited on 2-10-2010 by Rogeryermaw]

blogfast25 - 2-10-2010 at 12:43

Good work!

You could repeat that small test by means of some muriatic acid (HCl) instead of water, that would be definite proof... (AlP +3 HCl ---> AlCl3 + PH3). AlP may be more resistant to H2O than we might think...

Bear in mind though that although AlP will have a considerable Heat of Reaction (it can indeed be synthesised by direct union of the two elements), the HoF of Al2O3 is likely to be much higher, thus enormously favouring the formation of the Al oxide over formation of the phosphide, at least in near-stoichiometrical conditions. In the presence of large excesses of Al, formation of AlP would almost certainly occur. A formulational error could thus have dire unintended consequences!

We shouldn't exclude unreacted NaPO3 being present in the slag either: in a melt like that, dropping concentrations of one of the reagents may cause reactions speed to drop quickly and thus yield to be very incomplete...




[Edited on 2-10-2010 by blogfast25]

[Edited on 2-10-2010 by blogfast25]

Strepta - 2-10-2010 at 12:48

There will always be some traces of phosphine, evidenced as gas bursting into flame as it surfaces the water in the receiver. This is presumably due to an inability to completely de-hydrate the calgon. I performed my experiments 2-3 years ago (indoors) using my fume hood. Following the reaction I disassembled the apparatus underwater (after careful post-reaction weighing) and don't recall any evidence of a reaction between the slag and the water. An abundance of caution is always advisable, however.

"Incorporation" of the ingredients may be a factor. Have you ever made your own black powder and compared it to a sample of XXX Goex? It's no contest. I used pyrotechnic Al with the calgon and silica flour and whizzed everthing in a coffee grinder for 2-3 minutes.

I averaged about 50% yield (actual recovered vs theoret. available). The weighing indicated that about 70% of the theoret. P was released. Collection efficiency was therefore about 75%, which was good enough for my purposes.

not_important suggested using an equimolar amount of boria (boron trioxide) for silica, which I tried. It actually produced a marginally higher yield (52%) and the slag appeared to be a lesser amount. Boria begins to soften about 450C, considerably lower that pure silica.

Looking forward to your next results!

blogfast25 - 2-10-2010 at 12:57

Considering the cost differential silica - boria and the minor advantage you observed, I'm not sure that test would be worth the expense, at least not w/o some further optimisation to the current set up...

Boria isn't easy to purchase but it can be made quite easily from borax and muriatic acid. It just adds another step to the chain...

peach - 2-10-2010 at 14:04

First of all, nice work checking the slag. Maybe you could post some out to people with more things to test for precisely what's in it.

The boria thing may not be a simple case of the dry reagent costs. If it can be run at a much lower temperature, as strepta suggests, that alone may outweigh the extra cost by simplifying what's needed. For instance, it could be heated with nichrome wire perhaps, on a desktop, as opposed to needing a furnace outside.

I have the things to build a pretty darn funky furnace, but I'd still prefer a cute desktop thing that I can easily pack up, unpack and control without worrying about the fire, blower, exhaust and things like that.

If mixing is an issue, it could always take a whiz in the coffee grinder as he suggests. Or ball mill it. If it's going molten under the heat however, I'm not sure it needs to be so finely divided. Black powder does because it doesn't go through a liquid state, and solid / solid reactions ALWAYS benefit from finer grains and better mixing if increasing the reaction RATE is an issue.

Sometimes, of coarse, bigger grains and poorer mixing help by slowing things down to make them more controllable.

[Edited on 2-10-2010 by peach]

Rogeryermaw - 2-10-2010 at 15:36

thinking back to the first successful run i would say the AlP formation is certain. remember how i said that it popped in my hand as i was trying to clean out the reactor? with audible report and a visible flash? i quenched it after the run thus getting the inside of the reactor wet.

as far as what strepta said about the phosphine self igniting i don't think it does that without a small formation of di-phosphine as well. the di-phosphine ignites and then takes the phosphine with it. and drying the reactants helped to keep the spontaneous formation of phosphine low as on that first run i noted much fire bursting from the reactor and on successive runs it was little to zero since i began pre-drying the reactants.

if anyone wants to test this slag i'd be happy to send a sample. not sure if it should be labeled hazardous and what that would mean for shipping but if i crush it and send it i suppose it could be treated as sand

blogfast25 - 3-10-2010 at 07:24

Quote: Originally posted by Rogeryermaw  
thinking back to the first successful run i would say the AlP formation is certain. remember how i said that it popped in my hand as i was trying to clean out the reactor? with audible report and a visible flash? i quenched it after the run thus getting the inside of the reactor wet.



Hmmm... IIRW we attributed that to moisture in the mix, it doesn't necessarily point to AlP...

As regards analysis of the slag, the more I think about that, the more I think it's pro's job, because you've (and Strepta/Magpie) probably created a new mineral, a sodium silicato-aluminato-phosphato thingy-me-jibs! Grinding it down to extreme fineness (elutriating, even...) would then allow elemental analysis with X-ray Fluorescence (XRF) but that doesn't tell you in what molecular form the P is present...

Bar that, high temperature calcining in air would probably get rid of elemental P and phosphines (to P2O5) and convert any AlP to an aluminium phosphate.

The calcinate could then be treated with concentrated, hot H2SO4: the phosphates would then dissolve as H3PO4. After filtering/decanting/centrifuging/whatever the clear solution obtained would then contain the soluble PO4 (3-), quantity to be determined with various applicable methods...

Few of us here are equipped to pull that off...

In short, since as determining the composition of the slag, as part of an accurate yield determination, is probably outside the realm of our possibilities (I'm just throwing this is in as a teaser for Peach ;-) ), the best way forward would be to improve the collector. Strictly logically speaking...


[Edited on 3-10-2010 by blogfast25]

blogfast25 - 3-10-2010 at 07:26

Quote: Originally posted by peach  

The boria thing may not be a simple case of the dry reagent costs. If it can be run at a much lower temperature, as strepta suggests, that alone may outweigh the extra cost by simplifying what's needed. For instance, it could be heated with nichrome wire perhaps, on a desktop, as opposed to needing a furnace outside.


[Edited on 2-10-2010 by peach]


What makes you think boria would allow to run at lower temps? IMHO the rate determining step is the dissociation of P2O5 and that's VERY temperature dependent...

Rogeryermaw - 3-10-2010 at 09:15

the first things i'm going to try are stoich amounts of reactants and i have a few ideas for improving collector design. i think just by giving the vapor more time to reach the water and allowing it to cool a bit before it gets there will help control loss to air. this could significantly increase yield. my observation after running the experiment at night(the darkness allowed me to see the burning P vapor escaping from the lid) leads me to believe this is one of the areas of the system that can be improved upon the most.

on a positive note i did something for my safety and health today. my wife is bringing me a case of nitrile gloves home from work tonight and i picked up some neoprene gauntlets(almost elbow length). i also picked up a face shield and have a set of z-87.1 goggles.
next i'm going order one of those soviet era gas masks with replaceable cartridges...hopefully i can find cartridges that handle solvent and acid fumes...after that all i need (besides fume cabinet) is a good apron(and a lab coat to look the part;))





[Edited on 3-10-2010 by Rogeryermaw]

peach - 3-10-2010 at 23:10

I should girl it up on the sewing machine and make you an aramid & nomex onepiecey, that'd make a god damn awesome SM picture. :D

Before going to crystallography and such, it'd probably be worth looking for the phosphane again. Although, in terms of waiting for it to get through the post, the potential complaining that may occur if they manage to break the packet and spill the contents (no matter how well packed) and the time it'd take me to check it, it may be worth having a fiddle with the collector and reactants first, then upgrade to international collaboration if that stumbles as well.

If it has gone to some metal phosphorous compound, I wonder if there'd be an easy method for reoxidizing it to elemental phosphorus, without ending up with oxides or a gigantic bill. It's used as a phosphorus source in semiconductor labs, like Silane is for Silicon. I think they get the silicon back out on it's own with high temperatures under inert gas.

The boria thing, I have zero evidence of blogfast, just that Strepta mentioned it. In my rapid reading, I thought he was saying it starts producing at a lower temperature, but he does say it MELTS at 450C (which of coarse, isn't running and you're likely right about the P2O5 disassociation). What temperature did you have to run it up to Strepta?

If it melts and takes the phosphorus source into solution with it at 450C, I wonder if some form of electrolysis could then be used.

Strepta - 4-10-2010 at 08:54

Quote: Originally posted by peach  


The boria thing, I have zero evidence of blogfast, just that Strepta mentioned it. In my rapid reading, I thought he was saying it starts producing at a lower temperature, but he does say it MELTS at 450C (which of coarse, isn't running and you're likely right about the P2O5 disassociation). What temperature did you have to run it up to Strepta?



I mentioned boria as it melts considerably lower than silica yet produced only marginal improvement in yield. Make of that what you will. If sodium metaborate is one of the reaction products as not_important suggested, it does melt a bit lower (966C) than sodium silicate. In a setup like Roger's that may mean the post reaction slag could be kept molten as he is adding considerable heat input both during and after the reaction. I heated the slag with a meker burner before the reaction to initiate and after the reaction to drive the P out of the slag.

I measured the reaction temperature only one time using a thermocouple probe. Reaction onset was about 500C with a subsequent rise in temperature to ~ 700C. This was with silica. The reaction with pyrotechnic Al is self-sustaining once initiated.

watson.fawkes - 4-10-2010 at 09:16

Quote: Originally posted by peach  
If it has gone to some metal phosphorous compound, I wonder if there'd be an easy method for reoxidizing it to elemental phosphorus, without ending up with oxides or a gigantic bill. It's used as a phosphorus source in semiconductor labs, like Silane is for Silicon. I think they get the silicon back out on it's own with high temperatures under inert gas.
Silane spontaneously dissociates at moderately high temperature (420&deg; C according to Wikipedia), unlike phosphine.

metalresearcher - 4-10-2010 at 09:24

@peach: Nice to see that you're using Ubuntu as well....

@Rogermeryaw: How go you heat the stuff ? Propane ? How hot does it get or don't you have a pyrometer / thermocouple ?

[Edited on 2010-10-4 by metalresearcher]

Rogeryermaw - 4-10-2010 at 10:03

no unfortunately i haven't added that bit of equipment to my cache yet. my temps are estimated by the color charts available from metal working sites such as this: http://www.blksmth.com/heat_colors.htm
my furnace is wood fired with forced air. by the charts available i am reaching temps of at least 1150Celsius. note that the reaction and boiling of the melt in my experiments occurs at lower temp than this but that is how high i have pushed it. with less discretion it would certainly get hotter.



[Edited on 4-10-2010 by Rogeryermaw]

aax - 4-10-2010 at 10:38

Quote: Originally posted by Rogeryermaw  
the first things i'm going to try are stoich amounts of reactants and i have a few ideas for improving collector design. i think just by giving the vapor more time to reach the water and allowing it to cool a bit before it gets there will help control loss to air. this could significantly increase yield. my observation after running the experiment at night(the darkness allowed me to see the burning P vapor escaping from the lid) leads me to believe this is one of the areas of the system that can be improved upon the most.
[Edited on 3-10-2010 by Rogeryermaw]


You could add a spray nozzle to the top of the can that would spray the vapors. Might prevent some losses. The way I imagined it the spay nozzel is hooked up to an aqquarium pump and submerged into an ice bath next to the receiving vessle. A small hole or tube is placed into the side of the vessle to allow for drainage/circulation. Glass wool or something else could be used to prevent solids escaping from the receiving vessel. I havent been able to decide if the tube releasing the P vapor should be submerged, bearly submerged, or unsubmerged since I decided to use an ice bath. Maybe the tube releasing the P vapor should be inserted at an angle so the spray will not directly hit the tube and will instead be directed towards the spot where the bubbles will surface. Inert gas could prevent the vapers from igniting and could be used to pass the vapors through another colder collection vessle increasing yeilds.

Rogeryermaw - 4-10-2010 at 10:51

if delivery of vaporized phosphorus is not submerged you will certainly have to use inert gas or it will all be lost to atmosphere. there is no delay time to the ignition of phosphorus in vapor or even liquid form. if it is warm enough to be in a liquid state it will ignite instantaneously. as far as a spray nozzle i would fear pressurization creating an unsafe condition though i won't discount its possible value without trying it. beware the ignition of liquid phosphorus. you don't want to be close to it. it snaps and pops throwing flaming globs of phosphorus a good distance and the burns it can cause will turn necrotic. they are very slow healing. also cooling your collector may be advantageous but i would refrain from using ice. if your product solidifies in a closed system it will greatly frustrate your attempts to recover it. remember that phosphorus is deadly toxic and the less handling the better. i look forward to your experimentation results.

metalresearcher - 4-10-2010 at 11:21

Quote: Originally posted by Rogeryermaw  
no unfortunately i haven't added that bit of equipment to my cache yet. my temps are estimated by the color charts available from metal working sites such as this: http://www.blksmth.com/heat_colors.htm


True, temp colors depend on the ambient lighting. I did this with melting copper in bright sunlight, it looked like melting tin:

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thereelstory - 4-10-2010 at 11:24

So roger you are saying if you run this open system reactor vessel on the left and collector in water on the right, there will be enough remaining o2 in the tube to cause the liquid phase to self ignite? Ok so perhaps it does. At some point the 92 will be consumed and then things will be jolly good no?

Rogeryermaw - 4-10-2010 at 11:41

@metalresearcher. based on that my furnace may be significantly hotter. most of my work has been done in full sunlight.

@thereelstory mainly i was referring to his idea about using ice in the collector. if the output of the tube is exposed to air at all you can kiss the bulk of you phosphorus goodbye.

peach - 6-10-2010 at 08:06

Stick a bit of copper in there roger and you'll be able to see if it passes the melting point, without having to buy a thermocouple for a rough idea.

You must have a bit of copper lying around.

If not, I know where you can get some... :P:D

Rogeryermaw - 6-10-2010 at 08:14

already done that. i had a copper bottomed pot i set over the furnace to see what color the steel would get to...it's not copper bottomed anymore...;)

Rogeryermaw - 6-10-2010 at 08:16

Quote: Originally posted by peach  
I should girl it up on the sewing machine and make you an aramid & nomex onepiecey, that'd make a god damn awesome SM picture. :D



don't you mean S&M picture?:P

aax - 6-10-2010 at 09:34

After a few experiments I have decided that silicon dioxides main purpous in the reaction is to give the mix a thicker consistancy which slows down the reaction.

blogfast25 - 6-10-2010 at 12:30

Quote: Originally posted by aax  
After a few experiments I have decided that silicon dioxides main purpous in the reaction is to give the mix a thicker consistancy which slows down the reaction.


Are you possibly a troll, aax? If you've actually carried out any experiments and have drawn some conclusions based on them, then please report. Otherwise, please kindly eff off.

Panache - 6-10-2010 at 19:10

what are you melting the copper with in that video metalresearcher?

aax - 8-10-2010 at 13:01

Quote: Originally posted by blogfast25  
Quote: Originally posted by aax  
After a few experiments I have decided that silicon dioxides main purpous in the reaction is to give the mix a thicker consistancy which slows down the reaction.


Are you possibly a troll, aax? If you've actually carried out any experiments and have drawn some conclusions based on them, then please report. Otherwise, please kindly eff off.


Your weird...


aax - 8-10-2010 at 13:38

I read that P4 is soluble in benzene at high tempature. I also found out that if you were to boil the phosphorus in benzene at 200 degrees celcius under increased pressure the P4 would change to red phosphorus. UV rays speed up the transformation. The alternative to boiling it in solvent under increased pressure is to leave it out in the sun or under a tanning lamp. If your using UV rays alone you would want to increase the surface area. I'm sure the best way to increase surface area is to dissolve it into benzene.... That sounds like the most surface area possible to me.... Put it in benzene then leave it in the sun or under a tanning lamp for a month and then boil off the benzene... I haven't been able to find any information on the solubility of RED P4 in benzene. If Red P4 is insoluble then it should precipitate right out but thats only if it will even convert to red p while in solvent.


[Edited on 8-10-2010 by aax]

aax - 8-10-2010 at 13:54

Quote: Originally posted by Rogeryermaw  
if delivery of vaporized phosphorus is not submerged you will certainly have to use inert gas or it will all be lost to atmosphere. there is no delay time to the ignition of phosphorus in vapor or even liquid form. if it is warm enough to be in a liquid state it will ignite instantaneously. as far as a spray nozzle i would fear pressurization creating an unsafe condition though i won't discount its possible value without trying it. beware the ignition of liquid phosphorus. you don't want to be close to it. it snaps and pops throwing flaming globs of phosphorus a good distance and the burns it can cause will turn necrotic. they are very slow healing. also cooling your collector may be advantageous but i would refrain from using ice. if your product solidifies in a closed system it will greatly frustrate your attempts to recover it. remember that phosphorus is deadly toxic and the less handling the better. i look forward to your experimentation results.


Hey I had an idea... What if you coated the inside of the piping with mineral oil? The P should slide right down into the water. Another idea I had is to increase the diameter of the tube going into the water and coat the inside with mineral oil then submerg it into ice water which is in an ice salt bath... This should cool the tube up to a high enough point that the P4 will condence into a solid mass before it reaches the water.

peach - 9-10-2010 at 06:35

Not sure about the red P stuff, but with the pipe idea, a serious problem with that may be it trying to condense inside the pipe too readily, blocking it.

Even if the inside is coated with oil, there's a good chance the oil won't be enough, it will run off, heat will get to it or the P will simply catch on the none mirror smooth insides. Then all the blockage problems start.

A safer method, that'd probably yield even better, would be to submerge the pipe as normal, but then have metal wool or something similar (broken glass?) over the surface of the oil. The vapours will be more likely to catch on it, but the chances of it entirely blocking would be lower.

You would then have to wash the P back off with a suitable solvent though.

However, I doubt much of this specularizing is worth a pinch of silica until the main problem causer has been found in the first place. And I expect Roger is off having a break for a bit.

[Edited on 9-10-2010 by peach]

Rogeryermaw - 9-10-2010 at 07:32

minor break but i'm getting low on aluminum. i just ordered a huge cache of chems and gear (though i didnt get aluminum, i'll melt some down and attempt to atomize it myself in the next couple of days). mostly, though, my folks asked me to replace a large section of flooring in their home so i get to tear down some walls, pull a toilet and shower, install new subflooring, float and linoleum, then put all that back plus a new tub. i've been hijacked but i was actually planning a run this weekend with a couple of alterations in place. will report soon.

Eclectic - 11-10-2010 at 04:43

Does anyone know if phosphorus is heated by microwaves? If not, a carbon/phosphoric acid reactor and phosphorus condenser totally internal to a microwave oven might be possible...

[Edited on 10-11-2010 by Eclectic]

blogfast25 - 11-10-2010 at 08:37

Quote: Originally posted by Rogeryermaw  
minor break but i'm getting low on aluminum. i just ordered a huge cache of chems and gear (though i didnt get aluminum, i'll melt some down and attempt to atomize it myself in the next couple of days).


Melting and 'atomising' aluminium sounds like at project in itself. Why not attempt to use foil shredded in a food processor? Even pieces of about 1 - 2 mm should react well in your conditions...

blogfast25 - 11-10-2010 at 08:39

Quote: Originally posted by Eclectic  
Does anyone know if phosphorus is heated by microwaves? If not, a carbon/phosphoric acid reactor and phosphorus condenser totally internal to a microwave oven might be possible...



I accept this isn't much by way of criticism but that sounds like thoroughly naff idea to me... You need to get to red heat at least: domestic MW are definitely not designed for that...

Rogeryermaw - 11-10-2010 at 08:53

http://www.freepatentsonline.com/6207024.html is what you are talking about i believe. there are some scattered reports about this on the web but i have yet to see documented cases where someone has actually made it work on a lab scale. there is one forum that keeps coming up where a user claims success but is then unabe to reproduce the effect and is declared a crackpot. i'm looking for that entry but am unable to find it. will keep looking though.

Eclectic - 11-10-2010 at 14:06

Blogfast, havn't you seen the threads on microwave furnaces? The carbon in the reaction mix is a microwave susceptor and will get up to white heat. Of course it would need to be insulated. The question is, would the resulting phosphorus be heated by the microwaves as well.

peach - 11-10-2010 at 15:15

It is possible to produce crucibles that will absorb microwaves and melt metal.

I can't find the link to the guys site, but I remembering seeing it a couple of years ago, so it may have moved on more from there.

blogfast25 - 12-10-2010 at 08:48

Quote: Originally posted by Eclectic  
Blogfast, havn't you seen the threads on microwave furnaces? The carbon in the reaction mix is a microwave susceptor and will get up to white heat. Of course it would need to be insulated. The question is, would the resulting phosphorus be heated by the microwaves as well.


What I was saying was that domestic microwaves aren't suited for this purpose. I've used industrial MWs for various purposes but they're quite a different kettle of fish to domestic ones.

As regards the P, as it is undoubtedly contaminated, it will probably heat up.

Without a specific, tailor-made set-up, this is a recipe for disaster...

peach - 12-10-2010 at 14:03

This guy I was talking about was using domestic microwaves. With them being free from the tip, it's not a problem if you break one in the R&D phases. I can't remember what he was doing to make it work though! :mad: What he was using in terms of the absorbent.

Obviously, modifying microwaves at home, almost a kilowatt of invisible radiation emitting death, you better known what you're doing! Or you'll steam your eyes and brains to al dente without even feeling it.

Resonance and diffraction are a good place to start.

I wouldn't be too quick to dismiss domestic microwaves. From what I understand, the main advantage of a laboratory microwave is that they can produce single modes. I'm sure I remember reading published papers that were using domestic microwaves. A fridge pump versus diaphragms style debate.

Anyway, this way beyond where it should be. Something more basic is afoot with the yields than flames versus microwaves. A lot of what I've read about microwaves in the journals hasn't been eye poppingly impressive, as of yet. I've read one paper that is straight out incorrect, and I'm wondering how it even got published. It claims catalytic activity, yet absolutely there is absolutely NOTHING catalytic about it.

Also, if you start using microwaves for the P method, what are you going to use as a crucible? Even if it absorbs the microwaves, what's it going to do around the multiple ingredients, over a thousand C? Then you've got a whole other kettle of nasty fish to think about.

Nah, flames, hot wire elements and arcs until it's producing something over 50%. A simple demonstration is, they use arcs commercially. If it was more efficient to do it with microwaves, the commercial guys would almost certainly be onto it.

[Edited on 12-10-2010 by peach]

Rogeryermaw - 12-10-2010 at 14:32

before i had any successful experimentation, i had the thought to use the microwave method. like peach said, it is easy to get a very cheap or even free microwave. the thought i had was to use a hole saw(about half inch) since the controls and circuitry are normally on the right, cut a half inch hole through the left side panel and use a file to fit the holes to the neck of a glass retort.

retort-microwave.bmp - 315kB

my only concern would be if the heat would destroy the retort or could we find a suitable reducing agent that reacts at lower temp. and, of course, cutting a hole in the microwave might be dangerous...:P any thoughts?

peach - 12-10-2010 at 15:10

My thought is, you seem very good in paint. :P

I particularly enjoy the care put into creating the buttons and display. :D

The file to fit idea is good, the microwaves shouldn't be able to escape through that, unless the retort is made out of something transparent to microwaves. If it is, you'd need a cage around the collector, made from the screens in the windows of some other tip microwaves.

If you're DIY'ing the screens, you also need a microwave meter to check they're working.

One way around that is to surround the collector with the inside cavity of another microwave, then make sure everyone is a very long way away.

No idea about how it'd work, it'd be easier to try it in the real world. But I still think the flame method should be performing better before going microscopic on the heating.

The flame method is performing too poorly based on your results for it to be a matter of heat. It's the melt or the collector.

I'd try arcs before microwaves. Microwave transformers can be rewound to provide pretty much whatever you like at a few kW. And you can harvest carbon electrodes from old Zinc or Alkaline batteries.

I need to stop talking and get busy trying this myself but, at the moment, I'm covered in expanding foam, after a can of it burst mid a seriously DIY event; I now have a mushroom of urethane foam growing out of the back room floor. Not to worry, the floor sander will sort that.

[Edited on 12-10-2010 by peach]

Panache - 12-10-2010 at 18:52

from experience i you're intending to do that to a microwave you need to simply bend up a case for the entire shebang from sheet metal, nothing fancy, just no gaps, that way you're safe.

Rogeryermaw - 12-10-2010 at 21:30

well it's just tossing ideas around right now. nothing i will try right away. i think i would rather expend energy trying to make the equipment i have now more efficient. does aluminum block microwave energy? i wonder because we have all seen the arcing of an aluminum foil ball in the micro. does that not represent the waves bouncing back and forth on the metallic surface? if so then could not the entire neck and collection equipment be wrapped with multiple layers and sealed with aluminum ducting tape? or use a smaller microwave than the reaction machine, remove its door and place it against the side of the one the reaction is running in then just seal the cracks?

nothing i am wanting to try right away...just tossing off...some ideas;)

ok now i have a thought about what may be happening in the reaction with NaPO3+Al+SiO2...i believe bloggy to be correct about the formation of Al2O3 taking precedence due to its HoF driving the reaction but what happens to the rest of the aluminum after the O2 has been scavenged from the other reactants? it has nowhere to go but to combine with P until the aluminum charge has been exhausted...need to do some equilibrium work on this but it may just be an issue of being more precise with stoichiometry. i know we talked about this but i think it's time for another test. that may be why there was an unpleasant stench of phosphorus (possibly AlP or PH3) when breaking open the slag but no smoke as of phosphorus residue oxidizing. the smell of P2O5 is not as unpleasant as that mess was...

honestly fellas i'm not trying to get this crap in my lungs! i have been doing all my work outdoors but phosphorus and its compounds obviously have VERY powerful odors.




[Edited on 13-10-2010 by Rogeryermaw]

peach - 13-10-2010 at 00:34

As Panache says, a folded box would do. Aluminium will reflect it yar. In terms of simplicity, the foil idea is good, but it'd be quite easy to end up with leaks or have them form mid micronuking, so I'd go with getting a second microwave and chopping a hole in the side of it for the collector. As you can weld, and the enclosures are steel, you could weld the two together.

Microwaves from an oven can't escape a metallic enclosure provided the gaps are the same size, or smaller, than the ones on the grill covering the window. They have a long wavelength, so the grill looks like a solid surface to them. That's why phones are shit in terms of signal, they're "line of sight" radios, that really need to be able to see the next station. And the signal is strongly absorbed by all the water in the atmosphere. Hence the phone companies wanting to put masts everywhere, to reboost the signal and resend it to the next one. Saying that, a phone outputs not a lot of energy compared to an actual microwave, so the absorbency thing is not reliable. But the reflection is.

At one point, for reasons unknown, I placed an upside down wine glass in the microwave and then a Smartie sweet on the upside down base. When I returned a minute or two later, the glass had actually melted. :o I wasn't drunk either.

Since you're dealing with something genuinely toxic, you could pick up a respirator from eBay. You will have to out bid the weapons guys who want another one to hang on the wall and the kinky pReverts buying them for sex games, who'll probably strap a massive dildo to the intake on arrival (I have seen this). There is a fun respirator fact at the end.

I will continue filling cracks, in the walls, and have a think about the experiment and if I can easily check that melt (if you still have some lying around).

{respirator shenanigans}
After the twin towers maga fail, people went nuts buying respirators, thinking they were about to be chemo & bio attacked (places were selling out of them they were going so quickly). But a number of people have actually killed themselves putting respirators on and then forgetting to remove the covers on the cartridges, suffocating themselves but thinking they're being gassed. An operation that is as complex as, put it on, remove covers. The irony is quite outstanding, and fits well with my opinions on safety gear often becoming more of hazard than the original problem.

{edit: wavelengths}
The microwaves thing is kind of related to semiconductors. They produce the billionth of a meter transistors by shining a beam through a stencil onto the silicon. They want the beam to pass through the tiniest gaps possible. Even UV has too long a wavelength now, so they use electron beams. In another strange bit of science, solid objects can be treated as waves as well. By accelerating the electrons to very high velocities, the wavelength fits through the stencil. If they move fast enough, they can teleport through the stencil (seriously). That's how the memory in most digital electronics works now. So, theoretically, if you run fast enough at that wall, you'll teleport to the other side without actually breaking through it. Nice.... I have an evil scheme, suggest this to the next meth user you meet. "Just run REALLY fast! You almost did it last time!"

John, out

[Edited on 13-10-2010 by peach]

watson.fawkes - 13-10-2010 at 06:19

Quote: Originally posted by Rogeryermaw  
the thought i had was to use a hole saw(about half inch) since the controls and circuitry are normally on the right, cut a half inch hole through the left side panel and use a file to fit the holes to the neck of a glass retort.
A raw half-inch hole like that is going to leak, at the very least in the near field, and possibly through re-radiation in the far field. If you don't know what the near field is, I would recommend not playing with high-power microwaves.

watson.fawkes - 13-10-2010 at 06:28

Quote: Originally posted by peach  
As Panache says, a folded box would do. Aluminium will reflect it yar. [...]
Microwaves from an oven can't escape a metallic enclosure provided the gaps are the same size, or smaller, than the ones on the grill covering the window. They have a long wavelength, so the grill looks like a solid surface to them.
This only true if the box pieces are conductively bonded along their entire length. The resistance of a simple folded seam is high enough that the seam will leak. Adequate bonding means lots of bolts, to be safe, at a spacing of at most 1/8 &lambda;, or alternately welding or brazing the seam. If you've ever seen commercial waveguides, they have lots and lots of small bolts at all the junctions. These aren't for mechanical strength, but to provide adequate conduction paths transverse across the junction.

watson.fawkes - 13-10-2010 at 06:36

Also, anybody thinking about rebuilding a microwave oven needs to pay particular attention to the standing wave ratio between the magnetron and the cavity. The system just is not going to behave the same way it does with food in it. In that situation, you have a good absorber (think: like a beam dump) from the get-go; not always true for other uses.

At the very least, a thermal cutout on the magnetron is highly desirable. Even better is a field strength transducer near the emitter measure the field strength and to be part of control system to keep it under a known limit.

blogfast25 - 13-10-2010 at 07:09

Quote: Originally posted by peach  

Obviously, modifying microwaves at home, almost a kilowatt of invisible radiation emitting death, you better known what you're doing! Or you'll steam your eyes and brains to al dente without even feeling it.



Not to mention your gonads.

Isn't that what I was saying though, inter alea?

blogfast25 - 13-10-2010 at 07:15

Quote: Originally posted by Rogeryermaw  

ok now i have a thought about what may be happening in the reaction with NaPO3+Al+SiO2...i believe bloggy to be correct about the formation of Al2O3 taking precedence due to its HoF driving the reaction but what happens to the rest of the aluminum after the O2 has been scavenged from the other reactants? it has nowhere to go but to combine with P until the aluminum charge has been exhausted...


Roger, that just doesn't happen when you're in near stoichiometric conditions: there is no Al left to react with any P. Very small amounts of AlP could form but the equilibria of all reactions involved preclude the formation of AlP, unless Al is present in excess (and even then I'm not convinced: moisture is probably a greater danger than some excess Al)...

[Edited on 13-10-2010 by blogfast25]

peach - 13-10-2010 at 08:17

It, it being Roger, can weld, so he should be able to sort the chamber. But welding aluminium is extremely annoying if you don't have a fair bit of money spare. There is an aviation company that does rods for soldering / brazing aluminium, for people building or repairing their own planes. I say, screw all that, just use steel (like the steel chamber from another microwave).

Microwaves usually have a fair few thermostats strapped to the components that will get hot. I've run them many a time with no significant absorber in there and it's been fine. If you're going the microwave route, it's probably an idea to find the guy who was melting metals in a domestic microwave and ask about what he was using to catch the microwaves, then use that as the crucible or as a liner it sits in.

But more to the immediate point. You don't have many reagents in there Roger, three knowns. Given the amount missing, it's not going to be some trace contaminant doing that. If it was the steel, the container would be in a terrible state. So it's either;

- the heat not being enough to drive it all out of the melt (it's too soluble in the SiO2)
- it's not catching in the condenser or
- it's reacting in some unexpected way in the melt

Testing the collector for escape attempts would be the first thing.

- consider using something like a stainless coffee / tea / sugar container from the kitchen that has a tight fitting lid. You can usually get those real cheap from the budget stores. I have a bunch and the seal is about 1" long and requires a firm push to get it on.
- weld the pipe to the lid. You can always de-weld it later with the angle grinder.
- make another opening in the lid and pipe the atmosphere off

If the P is escaping, it will virtually all end up going down the tube. The end of which can go in another, cooler collector or to some form of test for it's presence.

If it's still not working after that, I'd consider the heat, solubility and melt.

Working that out, other than just ramping the temperature up and risking melting the container, will be difficult by eye.

The simplest proof of the pudding I can think of, for a gauranteed answer, is to waste some of your hard acquired yield thus far, and try reacting just the P with Al. oxide. Or add some to the Si. oxide and see if you can drive it back out. That will help tell you if it's getting stuck or reacting in an unknown manner.

You don't need to use it all. Use something like a stainless pipe nipple to make a tiny container, then use small amounts of the P and heat it in the same way as you would the normal melt.

So.... say 1g or a few of P, in with an equilivant amount of Al. oxide from the amount you'd expect it the melt. Heat, see if the P reappears.

Then.... small amount of P in with the Si. oxide, heat, see if the same amount comes back out.

If you're thorough, and there's a significant difference, it's in the melt.

I am beginning to suspect the melt more and more. Those arc furnaces they use industrially are insanely hot at the arcs, way over an atmosphere powered flame.

If it was it reacting with the Si. or Al. oxide, it'd be even worse at those temperatures. Which suggests, it's dissolving and just not efficiently boiling out at the atmospheric flame temperature.

Another tell tale sign would be you saying how the melt stunk of phosphorus. That's kind of to be expected given what's gone on in there, but the smell may also be a clue that it's still in there.

Can anyone think of a smart way to dissolve the melt but not alter the P? Or have it recoverable in a format where it could only have started as P, not an oxide or AlP?

[Edited on 13-10-2010 by peach]

peach - 13-10-2010 at 08:25

This is obviously starting to ask a lot of one guy (he's basically doing all the hard work), so I'm 100% happy to muck in with testing the melt and will commit a fair amount of effort to it if we can devise a solid method for checking it.

Testing it for AlP would be one of the firsts. I have a ton of gas handling stuff, am used to dealing with them and have the super balance and a respirator is in the post with some cartridges (I need one to sand the damn floor for a start :D normal dust masks leak too much over the 6h it takes).

More ideas for practical tests are needed. We may also need to make a group effort with the chemicals.

[Edited on 13-10-2010 by peach]

Rogeryermaw - 13-10-2010 at 12:02

Quote: Originally posted by blogfast25  


Roger, that just doesn't happen when you're in near stoichiometric conditions


that's why i said about reducing the aluminum to stoich amount.

Quote:
what happens to the rest of the aluminum after the O2 has been scavenged from the other reactants? it has nowhere to go but to combine with P until the aluminum charge has been exhausted...need to do some equilibrium work on this but it may just be an issue of being more precise with stoichiometry.


i'll have to look back but we had discussed using an excess of Al and up till this point that's what i have been doing. on the next run i will reduce that to stoich or perhaps 1-2% less. i really don't think there is much elemental P in the slag. if there were it would smoke upon being released through grinding. and since i had been using an excess of Al, that is the main reason i figured it was reacting with the top portion of the P being evolved in the main reaction.

all this talk of microwaves, while intriguing, is only conjecture until i put more work into the methods we are trying now.and i have no fear about escaping radiation. i'll put that bitch in the back corner of the yard and stay a couple hundred feet away while its running. c'mon we've all seen the retarded series "is it a good idead to microwave this?" on you tube. those idiots are still alive!

and microwaving my gonads may just be beneficial...i already have two kids i can barely handle and they won't be out of the house till i'm too old to party properly. definitely don't need more!:o

[Edited on 13-10-2010 by Rogeryermaw]

peach - 13-10-2010 at 16:10

Have you seen the episode of Southpark where Stan's dad discovers he can get weed legally, provided he has cancer. So he takes up smoking, sunbathing, drinking and microwaving his balls, then ends up bouncing around town on a space hopper permanently high, with all the women looking at his now bowling ball sized balls? :D

I was just checking your numbers. Keeping in mind that I've been on my feet for over 12h today painting, wiring plugs and endless other boring, rage inducing shit, and that I'm now getting a bit drunk prior to having a sleep, they seem pretty much okay. There is no huge excess of Al that would explain the lack of P in the result (from what I can see from some very rough calculations; I'll probably try checking them tomorrow depending on how quickly I start working again). The result is off by an order of magnitude, that is a darn big difference. Kitchen scales, after my examination of the anti-fatty Weight Watchers set I have, are not very good at all below 50 - 100g. But I'd be mighty surprised if even they weighed out 0.9g in place of 9g. You could easily see that with your eyes, without even picking it up.

You are in the realms, however, where kitchen scales are probably going to give poor results, 10% inaccuracies. They need about 100g on them before the error drops to a low percentage. 9g, whilst it's not going to weigh out 0.9g, I'd expect it to make about a gram or two of error on that. Anything between 1 - 50g, expect about 10% error from the kitchen scales, and it will decrease as the weight goes up to about 1%-2 or3% at 100g.

I still think there's something more afoot here. The scales aren't great, but they're not THAT far off. And the reactant masses aren't massively off either. Yet the yield is.

Nail the collector if you run it again soon, get that out of the equation. If you reduce the amount of Al and it's still doing it, it has got to be the melt. And I'd vote temperature and it not being driven to completion or fully out of solution. Again, arcs are fearsomely hot. Hot enough to start messing with the special refractories if too close. If it yielded the same amount with flames, they'd probably switch to that, as a gas flame is cheaper than an arc in terms of fuel (the electricity needs the gas / coal to be burnt, then converted and transmitted, then down converted, all involving losses and expensive power plants).

Have your younger Rogers started drawing on the walls yet? Kids are funny. I'd rather they drew on the walls than adults left dirty hand prints all over the place. Adults should know better, and the scribbling on the walls is at least colourful.

Rogeryermaw - 13-10-2010 at 18:31

i did some looking back at my records and it seems that i have been doubling the stoich amount of SiO2. presumably the excess O2 is turning the P into P2O5 yes no?

actually i took a bucket of joint compound and covered an entire wall of the house just for purposes of juvenile creativity. i can just sand it slightly and let em go at it again when they like. the she demon is 5 and the he beast is 2.

i have one of the blade scales from the local head shop. certainly not perfect but it's widely endorsed by dope dealers and you know how finicky they can be (captain, our sarcasm generators are at critical mass!!)

the collection effort is the first place i will start as it is basically a mechanical problem and that's my specialty. jus gonna hafta swallow my balls (may be difficult if they were basketball sized) and submerge the pipe deeper to give the vapor more contact time with the water.

ya i love that episode. would not be my chosen method to score weed since in colorado it seems anyone with a sniffle can get it, but i can't hate em for it. it's a step in the right direction since the govt. uses underground sales of contraband to fund illicit projects. make it legal and that slows their ability to take advantage of it's illegal status for private gain.

blogfast25 - 14-10-2010 at 05:18

Quote: Originally posted by Rogeryermaw  
i did some looking back at my records and it seems that i have been doubling the stoich amount of SiO2. presumably the excess O2 is turning the P into P2O5 yes no?



No, not likely. Al is just about barely capable to reduce SiO2,
because the Heat of Reaction for SiO2 + 2/3 Al ---> Si + 1/2 Al2O3 is just about negative (but for industrial production this reaction has to be heat boosted, with sulfur or K chlorate).

Off the top of my head P is wholly unable to reduce SiO2 to Si following SiO2 + 4/5 P ---> Si + 2/5 P2O5 because that reaction should be endothermic.

But because the reaction P2O5 + 10/3 Al ---> 2 P + 5/3 Al2O3 is vigorously endothermic, this MUST be by far the most preferred route for the Al.

Simply put, in a mixture of SiO2, P2O5 and Al, assuming there is just enough Al to reduce the P2O5, the Al will react only with the P2O5 and not with the SiO2. This is further helped by the fact that the P distills off, while any formed Si would not... If on the other hand there was also an excess of Al, some SiO2 would definitely be reduced too...

The excess SiO2 would help drive the displacement reaction 2 NaPO3 + SiO2 ---> Na2SiO3 + P2O5 further to the right (that's beneficial).

It would also act as a heat sink: the excess can't react and that means that the reaction mix needs more heat to reach the same temperature.

SiO2 also has a very high MP (1,650 C) and so while the sodium silicate acts as a melt viscosity reducer, the excess SiO2 probably doesn't even melt in your conditions...

The bottom line remains that for a good determination of yield you should try a strictly stoichiometric mix (but small weighing errors will not affect results significantly IMHO)...

[Edited on 14-10-2010 by blogfast25]

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