So I really cannot understand why any industrialist would in these
times, use anhydrous ammonia and crack it in a separate furnace;
instead of using far less harmful, cheap, forming gas, which gives
the same results. The only other industrial use (I can think of)
for anhydrous ammonia is in very large refrigerating plants.
Dear Mr. Burgess, Anhydrous Ammonia is used for many things that
benefit us every day. Here are a few.
Neutralizing sulfuric acid in the production of paraminophenol (used
in the production of acetaminophen) (aspirin), Manufacture of plastics
and intermediates, Metal processing, Etching gas in semiconductor
manufacturing Mixed with silane to make silicon nitride, Production of
hexamine for explosives (road building of course), Raw material in
the textile industry, Acid production, dyes, insecticides,
Fertilizers, Synthetic resins, Catalytic agent in manufacturing
processes, And finally a Refrigerant
For the jewelry industry, the cracking of anhydrous ammonia is
typically used in belt drive soldering furnaces where companies are
assembling metal parts on a larger scale. The hydrogen that is
generated by the decomposition of the NH3 prevents oxidation of the
parts being assembled. It is a production tool. This decomposition
reaction only occurs at high temperature so the ovens must be very
hot for it to work and the amount of available oxygen is tiny. The
small hydrogen flames that are seen eminating from the entrance and
exit of soldering furnaces prevent oxygen from entering the heating
(work) zone. Some oxides that might already exist on the parts
traveling through the work zone of the oven will be reduced back to
Mixtures of Hydrogen and Nitrogen, with a Hydrogen ratio higher than
about 10% can be explosive. Forming gas (25% H2 + 75%N2) can exist
at room temperature, can pocket under certain conditions, and can
explode with a spark without you ever having a clue that there was a
leak. Don't get me wrong, in certain applications, I also like and
do use forming gas. I have a gas blender and mix my own ratios
depending. There are always pluses and minuses to nearly all of our
tools. One bad thing about forming gas is that you can't smell it.
It will sneak up on you and then blow you to kingdom come. In the
wrong hands or used improperly, anhydrous ammonia can definately kill
you. At least you will know you have a leak before it does.
We have chosen to live and work in the jewelry business. We should
only work with tools and chemicals that we are trained to use and are
comfortable with. If anyone of us is asked to use a machine or
chemical that we are not trained to use and are not comfortable with,
get training or stay away from it. While it is always good to
question, learn, and even be skeptical, it is best not to dismiss or
condemn those that are trained.
Something my father always told me that kind of sums it up, (a
southern thing), "I drink 8 glasses of water a day for my health but
you can drown in an inch of it if your face down in it."
J. Tyler Teague
(Jewelry Engineering, Training, & Technology)