September 1, 2004
Modifications were made to the sodium cell I had used in August the distance between the electrodes had been increased and the cell had been wrapped in a range heating coil to allow me to heat it at will. The whole cell had then been placed in plaster of paris and allowed to sit. Initially molten NaOH was poured into the preheated cell and electrolysis was commenced, it was proceeding very rapidly, and the amps consumed were over 10. More NaOH was added, solid this time and it was quickly consumed. The cell go to within 5 cm of the top edge and I stopped adding NaOH, but the volume kept rising, I turned off the electrolysis thinking that it was bubbles making it foam form the gas evolution and that turning off the electrolysis would stop it, but it didn't make a bit of difference. There was a reaction going on. The putty that I had used around the electrodes in the bottom was rapidly reacting with the liquid NaOH now that I had more there and thus a larger surface area exposed, plus the temperature of the melt may have been hotter. I had to fill a 5 gallon bucket with water and while it was still 'boiling' throw the cell in it and run. Water shot out and stem and small explosions resounded, but it was over in an instant. It was really the only way, the reaction would not stop, and molten NaOH in contact with anything is a bad thing.
I still have the cell and it still heats, if I can find a new compound that is non-conductive and able to fill the hole at the bottom that will not react with molten NaOH then I am going to run this one again. The grass all around where the NaOH spattered died within a day but by the end of the season it had turned once again to green.
Up till this point I had success with some methods of production of phosphorus. This was a somewhat different approach though using somewhat less reactive Ca3(PO4)2 then my usual (NaPO3)6 the reaction with aluminum powder and fumed silica being the only constant. The apparatus shown above consisted of seven major parts:
(1) The torch, for heating and incineration of hazardous gasses which were vented via the tube (2) which lead them from the condensation chamber (5) through the one way gas valve to prevent suck back (4) through the hose (3). The retort itself consisted of the main chamber (7) which was constructed from a metal end cap for a pipe connected to a brushing, which lead off the neck of the retort (6) which was wrapped in fiberglass insulation to keep the phosphorus liquid until it reached the receiver. The screen in the receiver preventing phosphorus from floating to the top of the water held there so it had less chance of oxidizing.
I attempted the reaction with stoichiometric quantities according to the reaction:
3Ca3(PO4)2 + 10Al + 3SiO2 ---> 9CaSiO3 + 5Al2O3 + 1½P4
But there was no discernable reaction or gas evolution within 30 minutes with a propane torch. The charge was removed from the retort and appeared largely unchanged. I therefore changed the reaction mixture with one consisting entirely of aluminum and calcium phosphate, such mixtures provide a lower yield of phosphorus but are more exothermic and can start reacting at lower temperatures. This mixture also failed to yield phosphorus within 30 minutes. In either case a stronger flame must be applied to give results in phosphorus production.
September 27, 2004
This was another attempt to produce anhydrous hydrazine in one step from the reaction of urea with nickel powder as I explained in my April 10, 2004 entry. The difference being in this case (1) Better stirring of the solution (2) Nickel was truly powder (3) Mercuric oxide added with the nickel to promote carbonyl formation (4) Attempted to condense the hydrazine directly and not rely on reaction to determine if there was a yield (5) Reaction vessel flushed with H2S based on evidence that oxygen present severely retards Ni(CO)4 formation and H2S promotes it.
The mixture was heated and stirred an obtained a homogenous consistency. The temperature was held at roughly 140C for almost an hour and no visible reaction was taking place, just the urea volatizing and clinging to the inside of the reaction container as shown above. The reaction was discontinued and the glassware cleaned, turns out the reaction flask was attacked somewhat heavily by something, hydrazine does attack glass so this may be evidence that hydrazine was formed. Another member on sciencemadness claims to have used this process with iron powder over the course of several hours to make small amounts (drops) of hydrazine. If this is true a reactor would have to be made for continuous reaction involving large amounts of urea. Such as a beer keg with 25 kg of urea in it and 5 kg of nickel ball bearings to conduct heat along with powdered nickel and shavings, heated on a hotplate for 24 hours or more with a condenser coming off it, not a step I want to take for this fun little side project but if it worked it would be amazing.
I followed the reaction in a preparative inorganic chemistry book for the preparation of barium bromate. The prep called for reacting hot solutions of barium chloride and potassium bromate. The barium bromate immediately settling out of the solution leaving the potassium chloride in solution, the barium bromate obtained by filtration. So I made the hot concentrated solutions, my BaCl2 made myself from barium carbonate and hydrochloric acid, it had a very faint acid odor. Upon mixing the two hot solutions the beaker immediately ejected the contents, as seen above. I unplugged the hotplate and let everything sit until it cooled down. Impurities present in the chloride may have triggered it or I may have mixed the solutions too quickly, when they were mixed they made crystals which allowed the mixture to boil on them and also created a saturated KCl solution which may have superheated, there are actually a number of theories, I ended up with 10 g of barium bromate though. Cleaning up the mess was difficult, involving a dilute H2SO4 solution to render the barium somewhat tolerable, a rag, and some gloves. I got a slight case of barium sickness and was off my feet for a few days.
Back to experimental journal.