Newsgroups: rec.pyrotechnics
Subject: Re: KI
Organization: The Armory
Date: 1992-03-07 07:05:57 PST
In article <-8tsf8@rpi.edu> deangm@marcus.its.rpi.edu (Michael Christopher Deangelo) writes:
+I'm pretty new to pyrotechnics although I have been quietly
+reading this group for a while, trying to learn as much as
+I could. I'd like to try to make my first explosive
+compound - an extremely small amount of Nitrogen Triiodide.
+The question I have is this: How can I get pure crystals of
+Iodine? I had this idea that Potassium Iodide could yield
+the Iodine if I could add another halogen (chlorine maybe?)
+that would precipitate iodine.
+
+What is the best way to do this? What compound would be the
+best to do this? I have enough experience to follow basic
+laboritory procedure and safety. Before anyone sends me
+warnings, I don't plan on making a large quantity. Enough to
+balance on the eraser of a pencil is a rule of thumb I plan to use
+for my first time.
The first time I made NI3 I started with KI. My *recollection* of the
procedure I used (note that this was 13 years ago; I know because of my
vivid memories of the uses I put it to as a HS freshmen :-) is:
Mix KI with sulfuric acid (40% is fine). Heat. Iodine vapor boils off;
I collected it by placing a Petri dish of ice water over it. It condensed
on it forming tiny crystals which worked quite well for making NI3. At
least, most of it did; I left it to do its thing in my lab when I started
breathing iodine and sulfuric acid vapor...
Making the NI3 was even more fun. Having fairly little knowledge of
chemistry at the time (I got the recipe out of a 19th century book
titled _The Young Man's Encyclopaedia of Hobby and Sport_), I mixed the
iodine with ammonia in my makeshift laboratory apparatus... an aluminum
soda can with the top cut off. And left it to react overnight. Of course,
the ammonia ate through the aluminum after doing a good job on the iodine,
and much of it ran out on the floor (of my fortunately cobbled-together
outdoor lab), and dried, with the result that I got quite a surprise when
I walked in the next morning. In fact, little bits of it were snapping
away when I stepped on them for weeks.
John
Newsgroups: rec.pyrotechnics
Subject: Re: KI
Organization: The Armory
Date: 1992-03-28 04:10:35 PST
In article <1199@transfer.stratus.com> jsco@buzzardroost.az.stratus.com (Jeff Scott) writes:
+> I walked in the next morning. In fact, little bits of it were snapping
+> away when I stepped on them for weeks.
+>
+> John
+> --
+> John DuBois spcecdt@deeptht.santa-cruz.ca.us KC6QKZ
+
+I attemptec to make this usin store bought amonia and Iodine crystals. I
+got little or no reaction from this stuff, is it possible that the Amonia
+is not pure or concentrated enough or do I need to let it react for a long
+time. I let it sit for 30+ minutes and was reall disappointed! Any
+suggestions??
I tried it later with iodine crystals from a chemical supply house and
had much poorer luck. I think that the iodine crystals I made were so
small that it was possible to react them without dissolving them. With
larger crystals you would probably need to dissolve them and then perhaps
evaporate the solution to recover the NI3. You might try crushing the
iodine but the crystals I got by vapor deposition were powder-size.
I don't remember what strength ammonia I used. I know that I started
with cleaning-type ammonia solution, but I may have concentrated it. I do
recall concentrating some ammonia solution at one time by driving it off
from some and letting it be absorbed by some other but that might have been
later when I was trying to make NI3 with the larger crystals.
Do make sure that you don't use "detergent" ammonia. Pure ammonia
solution seems to be hard to find nowadays.
John