Summation of the
Sciencemadness Phosphorous Thread
May 6, 2012
Historical and modern preparations of elemental
phosphorus from phosphates are straightforward yet inconvenient for
an amateur chemist because they require very high temperatures,
provided by charcoal/coal fired furnaces in old methods and by
electric arcs in newer ones.
The phosphorous thread is long overdue for
summation. Beginning on page 15(2) replies to
the thread began including a disclaimer from individuals that they "didn't have
time to read" the thread before posting. In many cases even if this
disclaimer was not applied it was apparent that the ideas individuals presented
were simply rehashes of old material that would have been obvious if they had
just taken the time to read the thread. This summation covers all replies
in the thread to May 6, 2012 and covers 36 pages of posts totaling 897
individual posts. It is being compiled for the 10th anniversary of
Sciencemadness as I feel this thread is particularly significant in the amount
of effort put fourth by fellow forum members.
Now for my own disclaimer. I am
somewhat well versed in the literature preparation of phosphorous and have read
this thread beginning to end several times. I also have my own literature
references that I will add in parts to backup information already presented.
However all of this is being done through my own lens so to speak and some
spelling/grammar has been corrected. This
summation does not substitute for actually going through and reading the thread.
Some information that did not seem important to me may be important to someone
else. Point being I tried to include what I felt was of value, weather
this holds true for all instances however remains to be seen. Pictures
from the thread are not included in this summary however all references are
hyperlinked to their actual thread where the pictures can be viewed.
Please, I hope you enjoy this and hopefully it will provide guidance to any
reader in the future and spare them some headache in the process.
Table of Contents:
Section 1 - Production of
phosphorous from organic phosphate sources
Section 2 - Production of
phosphorous from inorganic phosphate sources
- Carbon as a reducing agent
- Aluminum / magnesium as a
- Other reducing
Section 3 - Production of
phosphorous from phosphides/phosphine
- Making phosphides
Section 4 - Production of
phosphorous from phosphoric acid
- From carbon using
Section 5 - Miscellaneous
methods to produce phosphorous
Production of phosphorous
from organic phosphate sources
Organic phosphate sources include bones,
urine, excrement, plant matter, anything that once was living or came from a
living being. The earliest isolation of phosphorus was indeed from organic
phosphate sources and it was only later that phosphorus was obtained from
inorganic phosphates such as calcium phosphate. Organic phosphate sources
are of advantage due to their availability although the downside can be low
phosphate recovery and always when working with organic material, stench.
Bone meal is available from many lawn and
garden centers as an organic phosphate source but it must be ashed before use.
Bone ash itself is also available from artists supplies where it is used for
pottery as well as for some other specialty uses. After which the phosphate is usually extracted by reaction with sulfuric acid followed by
filtering. This is known as the wet method of producing phosphoric acid. However after that point
the phosphate is removed enough from an organic source that I would
categorize it under one of the other headings.
In the opening post of the thread,
Polverone gives an excellent summary of the standard process of phosphorus
production using organic materials(1):
In the 1800s and earlier, phosphorus was prepared
by a number of processes. The earliest was that of Brandt, who
prepared it from human urine and charcoal. Later methods were
variations on the theme of "heat bone ash with charcoal at high
heat." The ashes of bones contain considerable phosphorus, combined
with calcium and oxygen, that can be reduced to the elemental state
with enough heat and a suitable reducing agent (carbon).
I will summarize the method given in Muspratt:
Animal bones are strongly heated in air until all organic matter has
been destroyed. The bones are powdered and to every 3 parts of
powder are added 2 parts concentrated sulfuric acid and 16 to 18
parts water. This causes some of the calcium in the bones to be
converted to calcium sulfate, which can then be removed by
The liquid thus obtained is evaporated to a thick, syrupy
consistency. It is mixed with one-fourth its weight of charcoal
powder, and then it is raised to near-red heat to make it perfectly
dry. The mass is transferred into a stoneware or iron retort in a
furnace. The retort has a copper tube connected to a heated
underwater receiver where the phosphorus can condense without
oxidation (and without solidifying and blocking the tube); the gases
that bubble to the surface are sent back to the chimney of the
furnace by a second, smaller copper tube. The furnace temperature is
gradually increased to white heat.
First comes off steam, then hydrogen and carbon monoxide and
dioxide, and finally, at bright red heat, phosphorus begins to come
over, accompanied by phosphine and CO/CO2 (it is difficult to be
sure about some of the exact products because of the archaic and
sometimes inaccurate terms used in the text).
Muspratt does not say precisely how long all of this takes, but
Wagner's Chemical Technology (1872) indicates that heat was
maintained for a long time, up to 48 hours.
Although the process starting from bones has been rendered
obsolete in industry a recent example(3) of it's use as a demonstration has been
found. The translation of that text(4) is provided below as the original
text is in German.
Cleaned, boiled and dried chicken bones are
burned with a bunsen burner on a fireproof surface and directly
heated with the flame until they have turned into white ash.
2g of this bone ash are mixed with 0,5g magnesium powder and 0,5g
The mix is heated in a test tube which is plugged with a glasswool
plug. After the reaction has finished, it is left to cool and the
glasswool plug is removed in a darkened room and observed closely.
A glow is visible on the glasswool.
When the residue in the test tube is mixed with water, gas bubbles
are evolved which self-ignite on contact with air. They are
In both of these cases it is the unrefined
calcium phosphate found in bones that acts as the phosphate source
although they differ greatly in the selection of reducing agent.
phosphorous from inorganic phosphate sources
Although the emphasis of this section is on
different reducing agents for inorganic phosphates, the reducing agent is only
one half of the equation (I'm not using that term literally). The
phosphate is just as important as the reducing agent when it comes to making the
reduction work as some phosphates are considerably more easy to reduce than
others. Still, in the spirit of categorizing things I am sorting these by
reducing agents used. And there are almost as many different reducing
agents as there are phosphates that people have tried. Please just keep in
mind however that one phosphate cannot be swapped directly for another, the
reaction might not work at all or it might go much too fast (think
Carbon as a reducing agent
Carbon is one of the most time
tested reducing agents of phosphates. The original alchemical
preparation relying on urine and other detritus succeeded in making
phosphorous due to all of the organic material present which broke
down to the carbon needed to carry out the reduction. On the whole
carbon reduction requires more intense and sustained heat than other
methods of phosphorus production although carbon has the advantage
of being as widely available as phosphates themselves.
The reaction between carbon,
silicon dioxide, and tricalcium phosphate (the standard phosphate
ore) at temperatures of up to 1500°C in an arc furnace(1)
is still the standard method to prepare phosphorous. Although
the problem posed to the at home chemist with this operation is
great and succinctly addressed in this quote from Polverone(1)
"Building a suitably airtight, nonconducting, refractory vessel for
an arc furnace is something well beyond my current engineering
skills/resources..." The reactions occurring in this method of
preparation can be shown as:
+ 3SiO2 + 5C ---> 3CaSiO3 + 5CO + 2P(gas)
Successful attempts to prepare
phosphorous using carbon as a reducing agent usually employ the
highest of temperatures in the field of phosphorous production.
One of the earliest successes detailed in the thread came from
Phosphorous1, his exploits are below(5):
I used a mixture of KH2PO4 and homemade willow
charcoal with no sand. The retort was made by 'encapsulating' a 10
ml lab glass vial with 'fire' cement and cooking this in the kitchen
oven at 250 C for 1 h. The spout was a piece of copper tubing sealed
on the retort with the same fire cement, (this comes as a ready-made
putty in my local hardware store). The furnace design is very simple
indeed: I have made a refractory kiln with a blowing pipe attached
to a 'cold-shot' powerful hair-drier. The furnace was fired with BBQ
charcoal. I have successfully melted iron in this, so I guess the
temperature at full regime, must have been in excess of 1300 C (it
looked so bright it would hurt my eyes to stare at it).
I have tried with thicker glass jars, without success. I guess the
glass, which replaces the silica, melts inside the fire cement
'mold' and acts as a flux aiding the melting of the phosphate. The
usual reduction reaction then occurs. It took 30 min or so at bright
white heat for the first spontaneously flammable bubbles to break
the surface of the water in the condenser. They produced
white-bright little flames, so I guess some phosphorus got lost in
that way. I am now thinking of repeating the experiment with ground
glass powder in a slightly bigger retort.
I still have my pellet of P4 in a small jar or water. It now sits
proudly on my desk.
Remember to keep the retort size as SMALL as possible so that it
will be easier to achieve and sustain internal high temperatures,
and do NOT use metal retorts. Too much heat is simply transferred
away to the spout and then to the water in the condenser.
Do not use gas torches unless you have an acetylene/oxygen source.
Go for a nice charcoal/air furnace which you can make with an old
bucket and refractory mix (and a nice hair-drier from your
Although many people have
used metal retorts for this process the point made above is valid,
unless the whole retort is placed inside of a kiln or the like it
does do well to conduct heat away and the heat from a torch is
feeble at best to get the reaction going. The following quote
is much more illustrative of attempts on in this thread to make
I have, a couple of times, tried straightforward
phosphate reduction with charcoal and heat. The vessel is a steel
pipe with a screwed-on cap at one end and a screwed-on nipple at the
other. The nipple has a section of copper pipe inserted in it and
sealed with furnace cement. I filled the pipe with a mixture of
diammonium phosphate and charcoal on the (admittedly dubious)
premise that the ammonium salt would have a lower decomposition
temperature and might help the reaction along. Plus it was the only
pure phosphate I could find on short notice.
I heated the apparatus with a large gas laboratory burner and had a
vessel of warm water to dip the copper pipe into. On my first
attempt, I got a lot of strange/unpleasant smelling gases and water
condensation at first (I wasn't going to submerge the tube until I
was sure something interesting would come out). I also saw some gas
leakage around the threads on the pipe. When it looked like the
reaction wasn't going anywhere, I removed the nipple/copper tube
assembly. I then heated the tube some more just for curiosity's
sake. Toward the end I started to see something interesting. The
mixture was melting and bubbling out of the tube a bit. I could heat
this portion directly with the gas burner, and when I got it red hot
I started to see a rather distinctive flame come out of voids in the
material. It looked like the flames I'd gotten by igniting red
phosphorus (obtained from match box strike strips) and it had the
After that minor encouragement I figured I'd clean things out and
try again, more patiently this time. However, it turns out that
whatever hot diammonium phosphate and charcoal turn into, it is
hard, insoluble, and tenacious. I had to painstakingly chip/smash
slag out of the pipe with a metal rod.
On my second attempt, much later, I kept the copper tube underwater
the whole time and tried to be patient with the heating. The gas
burner took a while (15 minutes?) to heat the tube up to red heat,
and even then could maintain that heat only where the tube directly
contacted the flame. It never got hotter than a medium-red. There
was a considerable amount of junk deposited in the water - mostly
copper salts created by hot/moist exit gases - but no phosphorus
that I could see.
As mentioned previously, the selection of
phosphate is just as important as the selection of reducing agent.
Supposedly phosphorite can be reduced with carbon at 500 to 600°C(59),
Strepta performed experiments using aluminum phosphate which has a
lower temperature necessary for reduction, 1100°C according to the
literature(6). Strepta's apparatus
consisted of a quartz tube heated by ni-chrome wire with a helium
sweep though it was later suggested that his helium, being balloon
grade, contained sufficient oxygen to decimate his yield(7).
Although a portion of the thread describing the experiment is quoted
below(8) I highly recommend reading
Strepta's detailed experimental description complete with photos to
which the figures listed below point to:
The reaction to be tried was: 2AlPO4 + C ==>
2Al2O3 + CO2 + 2P. The authors used equal weights of AlPO4 and C
although this results in a large excess of C by stoichiometry,
possibly to ensure that all of the AlPO4 is reduced.
I added 4.5 g of dried AlPO4 to 4.5 g of carbon black and mixed this
in a coffee grinder for two minutes. I was only able to get 4.7 g
(of the 9g total) of this mix into the reaction tube as I wanted it
no more than half full. More could have been added by reducing the
headspace above the mix and/or by tightly packing the mix.
4.7 g of reactants would represent .6g available P at 100% yield.
With a yield of 70% this amount would be reduced to about .4g.
When finally assembled and ready, I started the gas flow and let it
run about 10 minutes before ramping the temperature to 650 C. After
allowing the initial transient to settle, I continued to ramp the
temperature in 100 deg increments every 5 minutes. As the temp
transitioned from 1050 to 1150 C, the exit portion of the tube
darkened and the exhaust gas bubbles burst into flame as they
surfaced in the beaker. I continued the temp ramp to 1250 C. After a
few minutes at this temp, the probe readings (monitored at the 595
output) became erratic, dropping to as low as 600 and to as high as
1400. I suspected a poor connection in the circuitry or a failure of
the 595. After a few minutes, I shut the power off to the controller
but left the gas flowing and allowed the tube to cool. As it cooled
the readings became steady again and at 250 C I removed the
insulation and quartz tube from the galvanized pipe section and
unwrapped the kaowool. As I unwrapped the tube it broke into two
pieces. (Fig 7) The area under the heating element was extensively
cracked, and through handling, another section broke off. I removed
the tc probe and found that the Ni-Chrome sheathing had melted and
the melt had largely gathered into three globules. One of these had
a vitreous solid adhering to it –this appeared to be a piece of
Some phosphorus was evident in the exit section of the tube (Fig 9)
but this was not recovered. About 2.7 g of the original 4.7 g of
reactants was recovered (Fig 8) and this had not fused but was still
a loose powder as described in the article.
It appears that AlPO4 is reduced by carbon in the vicinity of
1100-1150 C as described, although I was not able to confirm the %
released (claimed as 72-83% after 1 hr) as the apparatus itself was
also reduced to junk. It also appears that a carbon reaction,
presumably with O2, is responsible for the extreme temperature
Another interesting variation (though adding additional
layers of unnecessary complexity) of the process(27)
(28) involved concurrently passing hydrogen chloride
through the mixture of bone ash and carbon. Of interest is that the
reaction appears to take place at red heat.
Improved method of extracting- Phosphorus from
—LeGenie Industrial describes a process
recently patented by II. Cari Mantrand, of Paris, for extracting
phosphorus from bones more economically than by the processes
heretofore employed. The calcined bones, reduced to a fine powder,
are mingled with a sufficient quantity of pulverized charcoal to
combine, as carbonic oxide, with all the oxygen of the phosphate.
The mixture is placed in an earthenware cylinder varnished on the
inside, filling the cylinder to three-fourths of its capacity. The
cylinder is then heated red hot, and a current of hydrochloric acid
gas is blown into it. The phosphate of lime is immediately
decomposed, forming chloride of calcium and carbonic oxide, while
the liberated phosphorus is evaporated and driven through a copper
tube, which leads into a vessel of cold water, where the phosphorus
is condensed. The chloride of calcium, disembarrassed of the
charcoal, in contact with sulphuric acid, regenerates hydrochloric
acid for a new operation. The labour of pulverizing the bones may be
saved by digesting them with a solution of hydrochloric acid; using
for this purpose the water of the condenser from the preceding
Aluminium / magnesium as a reducing agent
The allure of using aluminum
for the reaction of phosphates is two fold. First off, the
reaction is exothermic. Initially it was thought through
thermodynamic calculations that the reaction would be
self-sustaining although that seems not to be the case as it has not
been ignited by a thermite boost(23),
still it does overall decrease the energy burden that needs to be
supplied. Secondly the reaction imitates at a lower
temperature. These two boons look great on paper but the
temperatures involves still lie on the extreme end of home chemistry
and the engineering hurdles are still nearly as significant as they
are for the production of phosphorous from the reaction of
phosphates using carbon.
The form of the aluminum has
been simultaneously cited as unimportant (due to it being a liquid
at reaction temperature) to critical, various sources of aluminum
from aluminum cans to german pyro dark have been cited as being used
for these reactions.
In theory each of these
reaction involving aluminum could instead use magnesium.
Magnesium should give higher reaction temperatures (leading to
self-sustaining reaction) and possibly a lower initialization
temperature however work using magnesium has been limited. One
example is cited in the section on organic phosphates above(3)
where the demonstration reduces bone ash to elemental phosphorous
using magnesium powder. One possible complication however is
that formulations often include silicon dioxide to displace a
portion of the phosphorous and under reaction conditions the
magnesium reacting with the silicon dioxide to give magnesium oxide
and elemental silicon is a real possibility.
Still, all told aluminotheric
reduction of phosphate are the only reactions to yield significant
and reproducible amounts of phosphorous. Additionally
throughout the bulk of the thread these reactions also take
advantage of a specific phosphate, sodium hexametaphosphate.
This material is available over the counter for water softening
purposes and contains a high percentage of phosphorous coupled with
a low melting point of ca. 550°C(9).
In a reference(10)
quoted by Polverone(11) the following
details are given in a reference over 100 years old:
Action of Aluminium on Phosphorus
Compounds—Phosphorus vapour when led over powdered aluminium, heated
to a dull red beat in a current of hydrogen, combines with it with
incandescence, forming a dark greyish-black unfused mass, which is
decomposed in contact with moist (normal) air, forming PH3, and
leaving a greyish-white powder. It is decomposed also by water,
aluminium also by water, aluminium hydroxide and a brownish-black
residue being left ; and by acids and alkalis, which dissolve it
almost completely with evolution of PH3. The compound remains
unaltered when heated in air.
At more or less elevated temperatures, all phosphoric, acid
compounds (meta-, pyro-, and ortho-salts alike) are decomposed by
aluminium. Metaphosphates, however, undergo the most complete
change, according to the equation—
6NaPO3 + 15Al = 6NaAl02 + 2Al2O3 + Al5P3 + P3
The addition of silica effects the release of the remaining
phosphorus, thus :—
6NaPO3 + 10Al + 3SiO2 = 3Na2SiO3 + 5Al2O3 + 3P2
Calcium and magnesium salts are as efficacious as those of sodium,
but the superphosphates of commerce are not available for the
production of phosphorus in this manner. If, however, bone ash be
decomposed by hydrochloric acid instead of by sulphuric acid, a
material suitable for the purpose is obtained.
Hence phosphorus may be produced, with almost quantitative
completeness of yield, at relatively low temperatures...
A similar quote from Gmelin
provided by garage chemist(16) states:
"NaPO3 produced by melting NH4NaHPO4 is mixed with Al powder and
heated. Already at red heat, the mass begins to glow and emit P
vapors. Other phosphate salts can also be used, even the Ca and Mg
salts." Yet another reference(12)
given by pROcon(13) from the same era
gives a better indication of what is meant by 'low temperatures' in
the above quotation:
The applications of aluminum in the arts multiply
with much the same rapidity as do those of electricity. The
Berichte describes a new method of preparing phosphorus by its
use as a reducing agent. The process is so simple that it can easily
be illustrated on the lecture table. Hydrogen ammonium sodium
phosphate is fused in a porcelain crucible until it is changed into
sodium metaphosphate; aluminum turnings are then dropped into the
liquid, and the freed phosphorus bursts into flame. Now, if the
experiment is tried with a glass tube, instead of a crucible, a slow
current of hydrogen being passed over the mixture of the salt and
aluminum, the phosphorus distills into the cooler part of the tube
without the formation of any phosphoretted hydrogen. The residue
consists of alumina, sodium aluminate, and a phosphide of alumina -
By these steps in the process only 30 per cent of the phosphorus in
the mineral used can be obtained; but the phosphide is decomposed
entirely by heating it with silica, and this may be added at the
beginning of the experiment and the reaction proceeds without
difficulty and without loss.
It is advised that for the lecture table a combustion tube a yard
long be used; two and a half parts of aluminum, six parts of sodium
metaphosphate (obtained from heating previously the hydrogen
ammonium sodium phosphate) and two parts of finely pulverized silica
are placed in the tube, a slow current of hydrogen is passed
through, and heat is applied until the reaction begins. This is
shown by sudden incandescence, and phosphorus is seen to condense in
globules on the cooler part of the tube, at the end where hydrogen
Instead of this phosphate, any ordinary phosphate may be used, but
experimenters are warned not to use the superphosphates containing
calcium sulphate mixed with them, such as are used for fertilizing
purposes, because the sulphate is suddenly decomposed by the
aluminum with an explosion when a certain temperature is reached.
Whereas the form of the
aluminum used in the reaction varies greatly, the forum of the
silicon dioxide is stated explicitly to be finer than sand.
Finer than can be ground. The finest available. The
silicon dioxide will not liquefy at the temperatures that the
reaction initiates at. Although coarser grades have been used,
fumed silica, diatomite, kieselguhr(19)
and other very fines sources are usually recommended. This is
considered one of the hurdles to overcome to get good yields with
this reaction and usually necessitates prolonged heating and also
deters the reaction from being self-sustaining. However boron
trioxide may work in place of silica. The advantage being a
much lower melting point(14). If
too much aluminum is used and no silicon dioxide is used only the
phosphide will be formed and no phosphorous will be released(19).
Boric acid can be used in place of silica
6NaPO3 + 10Al + 3B2O3 = 6NaBO2 + 5Al2O3 + 3P2
the boric acid melts at about the same temperature as the sodium
metaphosphate, the sodium metaborate also has a slightly lower
melting point than the silicates.
I did this as a recreational exercise decades ago, no pressing need
for phosphorus so I didn't go for production data. Using a mix of Ca
and Na metaphosphates with B2O3 and SiO2 resulting in some fairly
low melting glasses and seemed to work OK with carbon as a reducing
agent; I assume because the reaction mix was fairly fluid throughout
the reaction giving better contact between all the reactants. On the
other hand it is not self-heating.
This bit of information was
successfully applied by Strepta(15) on
a future run:
I tried boron trioxide (from boric acid by
heating) in place of silica according to:
6NaPO3 + 10AI + 3B2O3 = 6NaBO2 + 5Al203 + 3P2 and had better yield
in terms of less solid residue (ash) after the reaction.
Stoichiometry of the above equation calls for a ratio of calgon/Al/silica
of 2.93/1.29/1. I mixed it accordingly and ground it thoroughly in a
mortar. The B2O3 is quite hard after it cools and a bit of work is
required to pulverize it. The end result is a mix which acts as a
fluid, rocking back and forth if swayed and spurting to the top of
the tube if the bottom is rapped sharply on a hard surface. Again I
took 3 grams of this mix and heated it at the bottom of a pyrex test
tube, the other end of which was wrapped with a damp piece of paper
towel. CO2 was used a a protective atmosphere and the exhaust was
routed through a half full 100 ml cylinder of H2O.
Heating of the tt was via a meker burner. The first noticeable
difference in using B2O3 was that the edges of the mix began to
shrink and curl before the reaction started, a result of the B2O3
starting to flow.
Once initiated the reaction was, again, self-sustaining, but
noticeably slower -12 to 15 seconds- than the 3-4 seconds previously
observed with silica.
Yield of P was .265 g from .512 available (identical result from 2
tries). The ash, however, was smaller and almost identical mass in
both tries. The residual was .500 g less the initial mass (2.500 vs
3.000). If all the difference is attributed to released P, the
efficiency of the reaction is ~98%. the missing 50% P could possibly
be lost as P2O5 (quite a bit of gas escapes from the 100 ml cyl.
during the reaction.
In practice the reaction
mixture expands after liquefaction to an estimated 3-4 times the
original volume(18) by the end of the
reaction. The slag solidifies at a very high temperature and
as such if it reaches the outlet it will plug the outlet.
Making sure the reactants are dry also reduces lost yield to
phosphine. It is also noted that phosphorous comes over last
and that the best yields are obtained on prolonged heating.
Another discovery in the thread was that adding a small amount (6-7
wt%) of sodium chloride to the reaction mixture may help 'cut the
reaction time in half'(20). This
was postulated to be caused by lowering the viscosity of the melt
although it was also noted that the final product obtained from runs
using sodium chloride as a flux looked to be of a lower purity(21).
This and many of the other practical notes were documented by
Rogeryermaw during his series of reactions following this process.
It should be noted that these
reactions all leave behind gross or at least a minimum of phosphide
contamination. As such the presence of phosphine/diphosphine
(spontaneously flammable and highly toxic) during the cleanup is a
distinct possibility(17) this is
complicated by the amount of manipulation needed to clean out the
reaction vessel where the slag leftover solidifies to a glass-like
In terms of application of
these teachings here are some selected successful attempts, first
Today I made a small amount of P according to the
6NaPO3 + 10Al + 3SiO2 --> 3Na2SiO3 + 5Al2O3 + 6P
Stoichiometric ratios of the reactants were mixed in a mortar. The
Al was 100-200 mesh, the SiO2 200 mesh pottery grade, and the NaPO3
was technical grade. My basis was 5g of P.
I have been wanting to try this for some time but have not been able
to find a suitable luting compound to join a ceramic retort to a
glass adaptor. I finally settled upon the best candidate that would
give me a truly positive seal, yet was releasable following the
experiment. This is Permatex high temperature RTV silicone. Previous
testing with a ceramic tile/glass slide showed that an RTV seal can
be destroyed in about 2 hours with con sulfuric acid at 125C,
thereby allowing recovery of the glass piece.
After loading the retort the 24/40 glass adapter was attached using
the RTV and allowed to cure overnight. Today the retort was
backfilled with argon, placed in a tube furnace, and a 400 mL beaker
of water located to provide a water seal for the adaptor outlet.
Over a period of 3 hours the temperature of the furnace was brought
up to a maximum of 1300C. Most of the time there was just a periodic
large bubble evolved indicating expansion of the gas in the retort.
However, at times the bubbling would stop, be erratic, or even form
a vacuum of about 1/2" water. During the last 100C or so it seemed
like no gas was formed, or any vacuum either.
P never did drop into the receiver as I had intended. When I removed
the insulation from the adaptor I found a small pool of solidified
P, tainted red from the RTV. Using a bunsen burner I melted the P,
picked up the furnace and drained the 4 or 5 drops of waxy, heavy P
into the receiver.
Next from Gurson who was able to perform this
project at school for a special assignment. Please check out
the original post(25) for a beautiful
12NaPO3 + 20Al + 6SiO2 =
6Na2SiO3 + 10Al2O3 + 3P4
The products reacting were 40 grams in total. NaPO3 was obtained
from heating NaNH4HPO4. The remaining glassy stuff was crushed (damn
hard it was) and dried in a drier at 80°C. SiO2 were not especially
small particles, just made it with HCl and NaSiO3. Al was 100 um.
The reaction vessel looks a lot like BromicAcids's second one. But
where he goes for a 'gass ball valve' (or something like that) I
used a overpressure of nitrogen of 1.1-1.2 bar.
The reaction vessel is 20 cm long, throughcut 5cm. The steel is 5mm
thick. A small pipe for the nitrogenflow is welded on the reaction
vessel. That pipe is 6mm through, and 10 cm long. The bottom of the
reaction vessel is welded airtight. (It's just closed, don't know
how to say that in english.)
The drainpipe for the gasses and P4 was screwed on the top of the
reaction vessel. The drain is 20mm through. It is has a 90° bow.
From the end of the vessel to the bow is the drain 15 cm, after that
40 cm long. Less heat was transferred to the water then we expected.
I used a acetlylene burner for
the heating. It melted the outside of the reaction vessel, so you
had to be careful not to burn a hole in your reaction vessel.
We put the end of the drain
under boiled distilled water. In patent 2,050,796 it stated that
dissolved oxygen in the water would oxidise the P4, so I boiled it
and put in a PE bottle for usage.
The vessel was first heated 15 mins to 400°C to get rid of the H2O
which would form PH3/P2H4. (Comprehensive Treatise on Inorganic and
Theoretical Chemistry, vol 8) We also added some carbon (tip from
Gmelins' to prevent phosfine forming)
After we heated it for about 2 hours the P4 started to came over.
The water was becoming a bit whitey, what was supposed to be
colloidal white P. After a while some solids were formed on the
bottom. The heat was turned off after 3 1/2 hour.” Gurson (207)
The maximum yield of a reaction
mixture of 40 grams was 8 grams White Phosphorous. We were able to
isolate some 5 grams of white P (measured under water, volume is x
ml, should weigh x grams but weighs x+y grams, so y could be white
P), and also 1.6 grams of Red P (from whiteP+UV -> RedP)
So the yield was.. 82,5%
Finally an early attempt by Cyrus(25),
one of the first on the forum that actually isolated phosphorous:
Today I tried to make some elemental phosphorus,
using trisodium phosphate as a fine powder (all ground by hand, my
hand hurt for a while, I must be holding the pestle wrong or
something), fine silica, and aluminum, in the form of snipped up
wires. There was an excess of Al because I figured it was the
reactant that would get mixed and used the most inefficiently.
I heated about 50 g total reactants in the distilling apparatus
described in my furnace thread for about 2 hours on "hellfire" .
(the part of the apparatus in the furnace was glowing reddish
orange. The only difference from the apparatus I used than the one
shown in that thread was that instead of bubbling the exit gasses
through a tin can soldered on, which I tried but wouldn't hold
water, I put another 90 deg elbow on the end of the pipe and a short
section pointing upwards, this part was filled with water.
As the thing was heated, phosphine (so I think) started coming out
of the end as a white mist, so I burned it off with my propane
torch, it made popping sounds and the mist disappeared.
After this, the water started getting milky, so I figured there was
some phosphorus in there, but at the very end of the run, I heated
the water up until it boiled, and then dumped what I supposed would
be a water/phosphorus mix into a tin can filled with water. All that
came out was water. Since the furnace ate a handful of wood or two
every few minutes, I had to stoke the fire a LOT, and the only way
to add more fuel was to take off the lid, set it down on some
bricks, add more fuel, and then put the lid back on. Every time I
did this some of the water spilled out. I don't think phosphorus is
a good grass fertilizer. The
furnace is still cooling down (I also fired some pottery) which
takes about 5-10 HOURS! Thusly, I cannot check for more details.
Although Cyrus didn't initially think he had obtained any
phosphorous the next day he found some hidden below the water in his setup(26)
although most of it had been floating on the water of clinging to the walls.
Hydrogen is able to reduce most
phosphates at temperatures significantly less than the temperatures
required for aluminothermic or carbon reduction. Temperatures
ranges have been quoted from 350-750°C for these types of reactions(29).
As the reducing agent is fixed for this section the selection of a
phosphate is all the more important and the temperatures required
vary widely as referenced below(30).
For the low-temperature production of phosphorus,
the most interesting candidates appear to be phosphates of lead,
bismuth, and antimony. The case of silver phosphate is rather
interesting too, as its reduction first yields finely divided
metallic silver plus phosphoric acid, which appears to be
catalytically reduced in the presence of the silver to give free
Other metals may be reduced at even lower temperatures, but they
give phosphides or phosphites, depending on metal and conditions,
never free phosphorus. I daren't wonder how much harder the
reductions would be with hydrocarbon gases in place of hydrogen...
yet I do wonder, given the difficulties of preparing pure dry
hydrogen from metal and acid as opposed to cracking the valve on a
gas line or cylinder.
Of course the major
complications are getting dry hydrogen and then after that working
with this extremely inflammable gas. There is also the danger
of creating phosphine.
Although the general procedure
for isolating phosphorous from phosphates by reduction with hydrogen
has been around for over a hundred years, most of the
experimentation has focused on a more recent patent designed to
produce isotopically labeled phosphorous from lead phosphate.
Evil_lurker summarized the patent procedure(32)
According to the patent,
lead phosphate or Pb3(PO4)2 is reduced under hydrogen or methane
(natural gas comes to mind) with hydrogen resulting in the highest
yields and methane about 50% of that.
The reaction consists of three stages:
1. The Pb3(PO4)2 is heated up to 300C to drive off any existing
2. Once the temp hits 300C the hydrogen is turned on and the
tempurature slowly raised to 500C. The hydrogen reduces the
Pb3(PO4)2 by ripping off the oxygen molecules and forming Pb3P2, aka
3. Upon the cessation of evolution of water, the furnace is again
slowly raised up to somewhere between 650-800C. According to the
patent, small amounts of PH3 are liberated at around 600C. This
makes sense, the Pb3P2 probably starts to break down somewhere
around 600C and thus liberates PH3, which subsequently start to be
reduced to H2 and elemental P at around 650C, so basically at the
beginning of the reduction temp the phosphine being liberated is not
hot enough to break down.
Still, the reduced reaction
temperature makes this extremely tempting for many experimenters
although few have made the attempt. The most focused attempt
to date by Strepta(31) is quoted below:
“I attempted the reduction of
Pb3(PO4)2 according to the method (H2 reduction of Pb3(PO4)2 @ 700C)
in the patent by Rupp, et al. I made a quartz tube furnace from a
section of .8” i.d. quartz tubing overwound with nichrome wire from
a toaster oven. It is shown in the first photo, with 115v volts
The actual color of the
energized nichrome was orange, the violet effect apparently a
combination of the photo flash and the emitted light. A firebrick
has been drilled lengthwise (1 inch dia) through which the quartz
tube is fitted and acts as insulation. The temperature in the tube
is monitored with a Fluke P 80 inconel immersion type probe embedded
in the Pb3(PO4)2 and connected to an ExTech temp meter. The input
and output ends of the tube are fitted with natural cork stoppers
which stand up to the heat far better than rubber. The cork to glass
tube joint is sealed with silicon rubber. To further ensure that the
system remains sealed, the ouput tube is run into a beaker of water
and produces visible/audible bubbles when everything is working
The tube is charged with Pb3(PO4)2 also made according to Rupp
(except for the ultrasonic agitation). The Pb3(PO4)2 was dryed in an
oven and ground to a flour –like consistency using a coffee grinder.
The hydrogen is generated by
electrolysis using sulfuric acid-water at battery acid
concentration, ie, sg =1.275. The anode and cathode are both made
from sheet lead (from Home Depot). The cathode is a 3 inch high
section spiraled inward for max surface area. A 3 inch wide funnel
is mounted over the cathode to capture the H2 and funnel it into a
10 in. long tube which is terminated with a rubber stopper. A glass
tube carries the hydrogen out and another hole in the stopper
permits a piece of #10 Cu wire to complete the circuit to the
cathode. The anode is also sheet Pb and sits immediately above the
Transformer & rectifier/fan
The 10 inch collection tube permits the generator to produce a
sufficient “pressure head” to bubble the H2 through the subsequent
H2SO4 and CaSO4 dryer sections.
The container is a tall glass flower vase. When operated (typically
@ 6 amps) for an hour, the solution becomes too hot to handle. It
also progressively darkens as it produces the brown precipitate,
PbO2, as can be seen in the sequence of photos. A strong odor of
ozone is apparent during operation.
In the experiment shown, about
12 g of the Pb3(PO4)2, prepared as described as above, was placed
into the quartz tube against a wad of fiberglass insulation to hold
it in place.
The hydrogen generator (6.6 amp) is started and run for about 10
minutes before the heating coil is energized. Heating is begun
slowly, keeping the temperature below 400C for the first hour. You
can see the moisture from the drying and later reduction condensing
in the far section at the output of the quartz tube.
After the H2O no longer appears at the end of the tube, the temp is
raised to 700 – 750C.
A red film deposit near the output of the tube appears first. Later
and further away a yellow film appears. There was also a popping
sound and some smoke from bubbles (PH3?) breaking the surface of the
water in the beaker.
Last picture is apparatus being disassembled. Only a film of P was
produced—no quantity of any significance. The viability of this as a
practical technique for producing even laboratory amounts (a few
grams) remains to be demonstrated.
Mellor in the Sciencemadness
library(33) covers many of the older
methods of phosphorus production however the reduction of phosphate
ores with hydrogen is mostly absent. However in one of his
later supplements the following information is supplied(34):
...many phosphates can be reduced by hydrogen at
temperatures between 300° and 750°C. Metals which do not form
phosphides, or give phosphides which are easily dissociated by heat,
are the most susceptible to this reduction. In these reactions
the metals is formed and the oxygen of the phosphate is
quantitatively converted to water. Lead phosphates are
particularly easy to reduce by hydrogen. For example,
pyromorphite, 3Pb3(PO4)2*PbCl2, starts to react at 300°C and is
completely reduced at 850°C.
Also from the
same source the decomposition temperatures of various phosphates
with hydrogen are listed with bismuth phosphate being the lowest
(425°C), silver phosphate being second lowest (425°C), antimony
phosphate (450°C) third lowest and lead phosphate fourth lowest at
Zinc has been proposed by
several posters for various advantages, real or not. Theoretic
runs though the advantages(35) as he
sees them in the thread: "zinc can be a gob instead of a powder,
it's a much less vigorous reducer than Al and so the reaction can't
get out of hand, there are two components instead of three
(phosphate and zinc as opposed to phosphate, Al and SiO2), the
reaction isn't stopped by a tough oxide layer, is faster and goes
much nearer to completion." However some of this may be
complicated by the volatility of zinc oxide(36).
Still, there are literature references to the use of zinc in this
reaction although it's ability to compete with other reducing agents
is dubious(37) as seen in the following
The Franck patent that the aluminum reduction
method is based upon also mentions the use of zinc as a reducing
agent. I have seen a mention much earlier, in the 1855 book
Outlines of Chemical Analysis: Prepared for the Chemical Laboratory
at Giessen By Heinrich Will, Daniel Breed, Lewis (Google Books)
that metaphosphoric acid or metaphosphates will liberate phosphorus
when heated before the blow-pipe with a bit of zinc.
I have verified without recovery (like the aluminum sheet
experiment) that chopped bits of zinc will cause the liberation of
phosphorus from hot fused metaphosphates. Even lead will do it. I
think the critical point in going from demonstration to production
isn't going to be the reducing power of the metal (within reason),
but ensuring that the kinetics and conversion efficiency are
optimized for production. Good mixing may strongly influence that
(good mixing, or ensuring that oxides are fluxed away to keep
exposing fresh metal to the melt).
Other reducing agents
The following methods were mentioned in passing
during the course of the discussion. They were not
investigated any further although they may prove useful. The
work has simply not been done.
Vulture mentioned in another thread that CaC2
would make a good reducing agent in such a reduction as phosphate
I suspect that sodium polysulfide would work well in a phosphate
4Na3PO4 + 2Na2S2 ----> 8Na2O + 4SO2 + P4
Sedit (40) -
Has anyone ever experimented
with fusing Hexasodium metaphosphate with Sodium acetate? I did a
little while ago just messing around and the mixture liquefied
rather quickly and a strong smell of garlic was released. It seemed
like the NaOAc was acting as a rather good carbon source and a flux
because once the melt was fluid there was a large release of
Phosphorus at a pace much faster the I have seen in the past using a
number of the following.....powdered carbon, powdered Aluminum,
Magnesium(the most potential IMO) I can't help but wonder
if Sodium acetate could become very helpful in creating White
Production of phosphorous
The forum has seen much
discussion regarding phosphides and phosphine however no practical
attempts have been made due to the intense toxicity, delayed
effects, and spontaneous flammability. Garage chemist seems to
be one of the greatest proponents of this method(41)
Heating PH3 results in the
splitting off of hydrogen to form solid, yellow lower phosphines. At
higher temperatures, I am sure those will completely decompose into
As phosphorus has a boiling point of 280°C and you will be working
at a much higher temperature, the P will condense as a liquid on the
tube walls as the reaction gas exits the hot zone. Just like the
unreacted 900°C sulfur vapor from my CS2 synthesis condensed as it
left the tube furnace.
Disproportionation of phosphine
is appealing because preparation of phosphides may prove easier than
making phosphorous directly from phosphates and an active metal
although no one has yet to attempt to prepare phosphides
intentionally. Beyond thermolysis the methods of converting
phosphine to phosphorus as discussed in the thread are few.
One recent example however involves the reaction of phosphine with
There is also the reported
reaction of phosphine with dimethylchloramine, which "reportedly"
gives free, elemental phosphorus and dimethylammonium chloride (as
http://pubs.acs.org/doi/abs/10.1021/ic50067a009). That would be
an EXTREMELY interesting solution to producing elemental Phosphorus,
as it would be feasible to produce elemental phosphorus using an RT
hydrolysis of MxPx' salts to give PH3
(logically, there should be no need to dry it), pass the gas
generated into a solution of dimethylchloramine (obviously an inert
atmosphere would be vital). But at least there is not the need for
the high-temperature on one end and then removal of the massive
amount of excess heat.
Another option to decompose
phosphides to phosphorous that has been discussed is the high
temperature decomposition of phosphides directly to phosphorous
although no literature references have been mentioned(46):
I think that at the very least
the following will occur, considering that cupric chloride
decomposes relatively easily into cuprous chloride and chlorine:
4Cu3P2 ----> 4Cu3P + P4
Another attack at copper
phosphide involved the availability of copper-phosphorous rods for
welding. These rods contain a phosphorous/copper alloy and it
was suggested that similar to dissolving phosphorous in lead and
electrolyzing the lead away to leave behind red phosphorous it could
be done using these rods(47).
Later research however revealed(48)
that the phosphide would oxidize at the anode giving dissolved
Additionally phosphine will
also react with aqueous solutions of nickel salts forming
nickel-phosphorous alloys however the use of these alloys in the
isolation of phosphorous is unknown(49)(50).
Preparation of phosphides
Providing there is a reasonable
way to prepare phosphorus from phosphine there is a need to make
phosphides for feed stock. That being the case there has been
some discussion on making phosphides intentionally. Some
phosphide preparations are available over the counter for control of
moles and the like although these only contain a few percent of
phoshide at best. In some countries different versions are
available however where the phosphide is prepared by a thermite-like
reaction between phosphate and aluminum(19),
these would make a better feed stock for this phosphine if available
additional information can be found in this quote by garage chemist(52).
The patent you attached is
about the usage of phosphine as a poison against rodents, and about
a mixture that creates calcium phosphide in-situ in order to avoid
the strict legal regulations that alkali and earth-alkali phosphides
are subject to due to their highly poisonous nature and ready
hydrolysis to phosphine even with aerial moisture.
A mixture of an alkali or earth-alkali phosphate, like Ca3(PO4)2,
and aluminum powder, burns similar to thermite when ignited and
leaves a slag that consists of Ca3P2 and Al2O3.
With moisture of air, earth or by contact with liquid H2O, 1g of the
slag that burning a mixture of 43% Al and 57% Ca3(PO4)2 gives
produces 72ml of gas (PH3) that imparts a lethal phosphine
concentration to 3 - 5 cubic meters of air.
Due to the admixture of Al2O3, the mixture hydrolyses much slower
than pure calcium phosphide.
Phosphide mixtures prepared by
aluminothermic reduction however are going to be nearly impossible
to separate so would need to be used as the slag obtained from the
reaction(53). However there are
several literature references for phosphides such as zinc phosphide(42)(51)
In our lab Zn3P2
prepared by thoroughly grinding a mixture of 3.8 g pure Zn3(PO4) 2
and 1.6g specpure carbon in a pulverizer. The powder was then
transferred to an alumina boat which was subsequently heated
in a vacuum furnace. After completion of the heat treatment the
samples were quenched to room temperature by blowing cold air over
them for about 5 min. A schematic diagram of the tubular vacuum
furnace designed for this purpose is shown in Fig. l. A facility has
been provided in the furnace for heating the samples under vacuum,
as well as in an inert atmosphere. Materials obtained by this method
after continuing the reaction for 16 h in vacuum have exhibited only
the prominent lines of Zn 3 P2- Zn3 P2 was also prepared by carbon
reduction of Zn3(PO4)2 in air and the yield of Zn3P2 was very poor;
it also contained some unreacted Zn3(PO4)2, and so only the material
prepared under vacuum/inert atmosphere was used as starting material
for crystal growth and film preparation.
Although reaction conditions
are not mentioned, one method to iron phosphide and subsequently
phosphorous is provided below (39) it
is unknown if this method of isolation, by heating a phosphide with
sulfur to free the phosphorus would work with other phosphides but
it would be open up a large window of opportunity. In addition
to the reference below there is a second reference in the thread to
using sulfur to free the phosphorous from zinc phosphide
...and R.A. Brooman heated a mixture of silica,
iron, coal, and calcium phosphate so as to form a fusible slag and
iron phosphide. The latter when heated with sulphur, hydrogen
sulphide, carbon disulphide, etc., furnished phosphorus.
Inorganic and Theoretical Chemistry: pg 740
Production of phosphorous
from phosphoric acid
Phosphoric acid can be reduced
to phosphorous with either active metals or with carbon, similar to
phosphates. However there are advantages, the liquid nature of
phosphoric acid allows a paste to be made beforehand that is
thoroughly admixed and the liquid reaction medium can help speed a
reaction. Additionally temperatures quoted in the literature
point to a lower initiation point than with mineral phosphates(16):
When an evaporated leachate of
bone ash with H2SO4 is heated with charcoal in a porcelain tube, P
evolution begins at 740°C, the largest part of P goes over at 960°C
and at 1170°C a 92% yield is obtained.
By-products of these reactions include water,
carbon monoxide, and phosphine. Phosphoric acid is noted in
some sources as being oxidizing such as this one quoted by
The pure acid is a colorless crystalline solid (mp 42.35C). It is
very stable and has essentially no oxidizing properties below
350-400C. At elevated temperatures it is fairly reactive toward
metals, which reduce it, and it will attack quartz.
Polverone is the man who
spearheaded this area of research wtih a vengence. During the
course of his inital investigations he prepared a large quantity of
phosphoric acid / carbon and used this as the basis for reactions
with zinc powder, silica powder, aluminum, and lead.
Highlights are detailed below.
From zinc powder / silica powder / phosphoric
acid / carbon (36):
I tried mixing zinc powder and
then zinc powder plus silica powder with the acid charcoal. Both of
these reactions went very poorly. I didn't notice any increased
production of phosphorus; in fact I couldn't see any production at
all since the zinc volatilized and left opaque oxide coatings on the
inside of the tube, but neither could I see any white smoke in the
light, so I don't think much P was being produced. Some zinc
phosphide was formed, evidenced by the scent observed upon adding
hot water to the cooled tubes.
From aluminum / carbon / phosphoric acid
Aluminum worked much better. In
the first attempt, I placed cut-up pieces of a soda can's pull tab
in the bottom of a test tube and poured the acid charcoal over it.
This showed the most rapid and easy production of phosphorus, giving
a healthy green combustion front racing up the tube as soon as the
bottom reached red heat. The rate of reaction slackened considerably
after that first burst, but it was still considerable compared to my
earlier efforts. All of the successful reactions leave a white ring
(presumably of phosphorus oxides) at the point in the tube where the
combustion front spends most of its time; this one's white ring had
some visible thickness by the time I was done. I scraped it with a
bamboo skewer and the residue seemed to absorb water from the air.
This showed an acid reaction with litmus (unsurprising).
For the final reaction I ground 400 mesh aluminum (the only sort of
particulate aluminum I have) with the acid charcoal and loaded it
into a test tube. There was some exotherm and funny smells even
before I applied heat. I ran a very small batch, less than 1 gram of
mixture, because I was wary of what might happen in the event of a
violent reaction or accidental tube break. The reaction actually
seemed harder to initiate than the one using chopped-up soda can
bits. It never got as vigorous either, but it did all right.
From silica powder / carbon / phosphoric acid
I had a lot of acid-impregnated
charcoal left after my last experiments. So I maintained heating all
night. Today it was slightly less damp than yesterday, but not much.
Anyway, I tried again with the charcoal, this time grinding in some
silica powder. There was a little bit of phosphorus production. It
wasn't much, but it was steady as long as I kept the base of the
tube at a bright orange. I can't imagine how many hours it would
take to get 100 mg out of a test tube like this, even if I could
collect the phosphorus instead of burning it.
From lead wire / phosporic acid(56):
2 g of lead wire were placed in
a borosilicate test tube along with 1 ml of 85% H3PO4. This was
heated in a propane torch flame, carefully at first as water was
driven off. Heating was increased, and the lead melted under the
acid. After a couple minutes a thin stream of whitish smoke started
wisping from the test tube. The smoke had the characteristic smell
of burning phosphorus. It occurred to me after a bit to turn off the
light, and I saw a mysterious and beautiful site: there was a
greenish light appearing about halfway down the test tube. The light
moved up and down the tube as the heating was increased and
decreased in intensity, probably representing the rate of production
of flammable vapor vs. its interaction with the atmosphere. After
admiring the green glow for a few minutes, I broke off the
From carbon using microwaves
Microwave heating of phosphoric
acid and carbon has promise in that both are able to readily absorb
microwaves. The issues to be encountered in this process are
aptly described by Polverone(58):
The reaction takes place at
much lower temperatures than the conventional arc furnace process.
The problem (or problems), of course, is that the phosphorus still
needs to be protected from oxidation, you need a relatively
heat-resistant and microwave-transparent reaction vessel, and it's
going to be tough to condense and collect the phosphorus if you're
trying to come up with something using a domestic microwave oven.
That being the case there is
little research done in this vein but there is plenty of talking.
Garage chemist can be quoted as saying "I
think that the microwave heating of a charcoal/phosphoric acid mix
to produce white phosphorus is the most promising home method for
phosphorus production." Citing that even silver can be
melted in a microwave using carbon as a microwave absorbent(61).
One member, Halogenstruck actually attempted a small scale
I MIXED 100% extra mole/mole
charcoal powder and 85% H3PO4 then i put it at the bottom of a test
tube, covered by a thin glass wool layer, upside-down inside a cup
in first 4 or 5 minute, a lot of gas was evolved. but 16min was
necessary to allow P ring comes down the tube.
because P releases very fast but immediately because of heat turns
to red/violet P.
red/violet P melting point or sublimation temperature based on
wikipedia is between 416 to 590C.
therefore it does not come out easily as mixture does not warm very
well and needs lengthy heating in microwave to get warm enough all
the area inside.
The holdup also seems to be
making a proper reaction vessel for microwave use as the microwave
is easily able to heat the mixture to temperature. A lot of
the discussion revolves around US Patent 6207024 posted by Polverone.
Miscellaneous methods to
And then there are the rest.
Although the vast majority of the methods to prepare phosphrous are
shown in previous sections there are a few that defy the listed
Electrolysis is one of the more
off-beat methods of isolation. In the thread two different
electrolysis procedures are mentioned. The first is the
electrolysis of bone ash (calcium phosphate) in molten cryolite
The second method comes from Gmelin and is by electrolysis of molten
sodium hexametaphosphate with a nickel cathode(16).
Another interesting reaction
noted was what sodium hypophosphite decomposed when heated to give
phosphorus and phosphine among other products(62).
Red phosphorous is produced by
using mercury to reduce phosphrous (III) bromide over the course of
several days in a Parr shaker(63).
Polverone. (2002, June 26). Preparation
of elemental phosphorous [Msg 1]. Message posted to
Myfanwy. (2009, November 19).
Preparation of elemental phosphorous [Msg 368]. Message posted to
"Knochen enthalten Phosphor."
Universität Paderborn., n.d. Web. Retreived May. 05 2012. <http://groups.uni-paderborn.de/cc/studienarbeiten/seidel/allgem_chem/versuche/p_kno.html>
garage chemist. (2006, March 9).
Preparation of elemental phosphorous [Msg 181]. Message posted to
Phosphorous1. (2004, October 7).
Preparation of elemental phosphorous [Msg 108]. Message posted to
IEC vol. 21,
no. 11, page 1130
Picric-A. (2010, March 1).
Preparation of elemental phosphorous [Msg 450]. Message posted to
Strepta. (2010, February 28).
Preparation of elemental phosphorous [Msg 432]. Message posted to
Polverone. (2002, October 12). Preparation
of elemental phosphorous [Msg 18]. Message posted to
Aluminum as a Reducing Agent, L.
Franck. Chem. Zeit. 1898, 22, , 236-245.
In:- The Journal Of The Society Of Chemical Industry. 17, , 612-613.
Polverone. (2002, August 24). Preparation
of elemental phosphorous [Msg 5]. Message posted to
The Manufacturer and Builder Volume
0026 Issue 8 (August 1894) (Direct
pROcon. (2002, October 10). Preparation
of elemental phosphorous [Msg 17]. Message posted to
not_important. (2008, June 16). Preparation
of elemental phosphorous [Msg 325]. Message posted to
Strepta. (2008, July 2). Preparation
of elemental phosphorous [Msg 339]. Message posted to
garage chemist. (2005, September
of elemental phosphorous [Msg 159]. Message posted to
Rogeryermaw. (2010, September 3). Preparation
of elemental phosphorous [Msg 563]. Message posted to
Rogeryermaw. (2010, September 7). Preparation
of elemental phosphorous [Msg 573]. Message posted to
garage chemist. (2009, December
of elemental phosphorous [Msg 396]. Message posted to
Rogeryermaw. (2010, September 24).
Preparation of elemental phosphorous [Msg 602]. Message posted to
Rogeryermaw. (2010, October 29).
Preparation of elemental phosphorous [Msg 722]. Message posted to
Magpie. (2010, March 5). Preparation
of elemental phosphorous [Msg 452]. Message posted to
blogfast25. (2009, December 9).
Preparation of elemental phosphorous [Msg 409]. Message posted to
Gurson. (2006, April 16). Preparation
of elemental phosphorous [Msg 212]. Message posted to
Cyrus. (2004, August 26). Preparation
of elemental phosphorous [Msg 80]. Message posted to
Cyrus. (2004, August 27). Preparation
of elemental phosphorous [Msg 83]. Message posted to
The WiZard is In. (2011, April 12).
Preparation of elemental phosphorous [Msg 783]. Message posted to
The Chemical news and journal of
industrial science, Volumes 3-4 May 4 1861
Polverone. (2002, August 24).
Preparation of elemental phosphorous [Msg 6]. Message posted to
Polverone. (2007, February 23).
Preparation of elemental phosphorous [Msg 274]. Message posted to
Strepta. (2007, March 3). Preparation
of elemental phosphorous [Msg 275]. Message posted to
Evil_Lurker. (2005, May 5).
Preparation of elemental phosphorous [Msg 135]. Message posted to
Mellor. A Comprehensive Tretise
on Inorganic and Theoretical Chemistry Vol.8 1931
J. W. Nekkirm D.Sc., F.R.S. Supplement
to Mellor's Comprehensive Treatise on Inorganic and Theoretical Chemistry
Volume VIII Supplement III - Phosphorous: Longman pp 111-112 1971
Theoretic. (2004, September 18).
Preparation of elemental phosphorous [Msg 99]. Message posted to
Polverone. (2005, September 6).
Preparation of elemental phosphorous [Msg 155]. Message posted to
Polverone. (2008, July 17).
Preparation of elemental phosphorous [Msg 335]. Message posted to
madscientist. (2002, August 24).
Preparation of elemental phosphorous [Msg 4]. Message posted to
BromicAcid. (2004, January 14).
Preparation of elemental phosphorous [Msg 50]. Message posted to
Sedit. (2012, January 1).
Preparation of elemental phosphorous [Msg 877]. Message posted to
garage chemist. (2008, June 5).
Preparation of elemental phosphorous [Msg 314]. Message posted to
Un0me2. (2010, August 21).
Preparation of elemental phosphorous [Msg 512]. Message posted to
Ronald E. Highsmith, Harry H. Sisler
New reaction of
chloramines with phosphines Inorg. Chem.,
(9), pp 1740–1742
Un0me2. (2010, August 21).
Preparation of elemental phosphorous [Msg 523]. Message posted to
garage chemist. (2008, June 5).
Preparation of elemental phosphorous [Msg 316]. Message posted to
madscientist. (2003, February
1). Preparation of elemental phosphorous [Msg 31]. Message posted to
BromicAcid. (2003, December 26).
Preparation of elemental phosphorous [Msg 46]. Message posted to
A. Rosenheim and J. Pinsker, Ber.
1910, 43, 2003
Chemical Elements and their Compounds
Vol I 1962 Sidgwick pg 730
BromicAcid. (2004, September
10). Preparation of elemental phosphorous [Msg 98]. Message posted to
K.R. Murali, B.S.V. Gopalam. Preparation of Zinc Phosphide:
JOURNAL OF MATERIALS SCIENCE LETTERS 5 (1986) 989-990
garage chemist. (2007, April 7).
Preparation of elemental phosphorous [Msg 283]. Message posted to
Vulture. (2002, October 13).
Preparation of elemental phosphorous [Msg 21]. Message posted to
madscientist. (2002, October
18). Preparation of elemental phosphorous [Msg 26]. Message posted to
Polverone. (2005, September 7).
Preparation of elemental phosphorous [Msg 160]. Message posted to
Polverone. (2005, May 10). Preparation
of elemental phosphorous [Msg 136]. Message posted to
Halogenstruck. (2010, April 8).
Preparation of elemental phosphorous [Msg 483]. Message posted to
Polverone. (2002, June 28).
Preparation of elemental phosphorous [Msg 2]. Message posted to
BromicAcid. (2004. Febuary 13).
Preparation of elemental phosphorous [Msg 56]. Message posted to
BromicAcid. (2004. Febuary 9).
Preparation of elemental phosphorous [Msg 53]. Message posted to
garage chemist. (2006. December 26).
Preparation of elemental phosphorous [Msg 254]. Message posted to
garage chemist. (2007. January 29).
Preparation of elemental phosphorous [Msg 271]. Message posted to
Sauron. (2006. December 24).
Preparation of elemental phosphorous [Msg 226]. Message posted to
S.C. Wack. (2006. December 26).
Preparation of elemental phosphorous [Msg 252]. Message posted to
Zhurnal Prikladnoi Khimii 44(2) 429-33