Uses for Nitric Acid

Jewelry Discussion
21

To put the “Why not put it in the ground or drain?” question into
perspective - yes nitrates are good for plants. Your liter or pint
of 70% represents 25,000,000% of their RDA of nitrates. A rose bush
is using ppm of nitrate, and you have 2 grams in that bottle (or
however much exactly). The same is true with waste treatment - they
could handle it in the quantity of water they use, but it would put a
blip on the radar. Frankly, this being a very un-PC thing to say - a
person who washes some stray soil with a bucket of nitrates is not
going to knock the world off of it’s orbit. It’s that the mentality
that “It’s OK to do that.” is how all of the earth has become
polluted, and we all just need to stop doing that. As I said in my
first post to this - It’s plutonium - I could use it, myself, but
there’s a reason you can by HCL, NaOH, Phosphoric, and others in the
hardware store, but not nitric acid. It’s just too dangerous for the
public. Then again, IT’S not HF or perchloric, or nitrogen pentoxide
either…

22

G’day; I don’t know if my contribution is the one this comment is
aimed at, but I wanted to point out that nitric acid is by no means
to be confused with a nitrate, Which is a salt, from the reaction
between the acid and a metallic compound - example: potassium
nitrate.

If it is desired to get rid of nitric acid, or a solution of it’s
salts the simplest way is to mix it with a non reactive solid
material to dilute it. Do NOT use sawdust or any organic material, as
this may catch fire spontaneously, but mix with sand, or powdered
clay, or even dry earth. Leave it a while, then sprinkle it over a
large area of ground.

This may not be “politically correct” but it is practical for small
amounts.

Cheers for now,
John Burgess; @John_Burgess2 of Mapua, Nelson NZ

23 
To put the "Why not put it in the ground or drain?" question into
perspective - yes nitrates are good for plants. Your liter or pint
of 70% represents 25,000,000% of their RDA of nitrates. A rose
bush is using ppm of nitrate, and you have 2 grams in that bottle
(or however much exactly).

If I did not miscalculate, there are 973 grams of the pure acid in
one liter, and this means there are 957 grams of the nitrate anion
contained in it :wink:

Matthias

24

John,

There was a Jewery/Lapidary store in my area that went out of
business. I ended up with a bottle of 70% Nitric acid. I would
like to know what are the uses for Nitric acid. Also the way to
neutralize it when done using it.

Short answer: If you still have that bottle of acid, find a college
or university and talk to the chemistry department about taking it
off your hands. They will know the safe method of disposal for any
acid of any concentration. They also have the MSDS (Material Safety
Data Sheet) on file for every chemical or acid used in any of the
classes.

An example: A few years ago while working for a major aircraft
company a salaried office worker in the department where I worked
came to my station and told me to start using a compound called
“keller’s etch” to prepare parts for inspection. The next day there
was a small bottle of the compound on my work table. Not really sure
of the safety of it, I asked for and received the MSDS for the
keller’s etch and all of the ingredients used to make it. Where it is
made I don’t know and don’t really want to know. The stuff was a
mixture of nitric acid, hydrofluoric acid, and hydrochloric acid with
the three acids making ten percent of the volume. The rest of the
volume was distilled water. The MSDS for one acid cautioned against
contact with aluminum. Another MSDS cautioned that if exposed to
certain acids (the first acid), extremely high heat could be
produced. The third MSDS cautioned that the acid should be used in a
well ventilated booth while wearing full protective clothing. The
level of protective clothing was very limited. These concerns were
presented to a few safety representatives at the company along with a
request for a clear glove box enclosure in which to use the compound.
Less than ten days after the compound arrived, it was removed from
the area.

Sorry about the delay in this response, I had been unable to get
email for a few days. Be very careful with that acid.

James Good

25 
If I did not miscalculate, there are 973 grams of the pure acid in
one liter, and this means there are 957 grams of the nitrate anion
contained in it ;-)

I apologize for checking the work…being a numbers buff, I couldn’t
resist:

Specific Gravity 70% HNO3 solution = 1.4134 (compound 6420 Merck
Index tenth edition)

  • One liter would weigh 1413.4 grams

  • 70% weight of liter gives weight of HNO3 = 989.4 grams

  • Molecular Weight of HNO3 = 1+14+(3)(16) = 63 daltons

  • Ionic Weight of NO3 = 14+3*16 = 62 daltons

  • Weight per liter NO3 = (62/63)(989.4) = 973.7 grams

  • Nitrogen loading as N (14/63)(989.4) =219.9 grams

Joseph Salvato’s book, Environmental Engineering and Sanitation
gives a clue as to the normal nitrate loading in both household raw
waste water. Table 4-1 on page 381 of the Third Edition lists the
numbers (unfortunately not the units of measure but I infer that they
meant parts per million or effectively mg/L) Household waste water
was listed as 84.

So one liter of 70% nitric acid would have the same nitrate load as
219.9/0.084 liters of raw household sewage. (2617 liters) One gallon
= 3.785 liters therefore in gallons the loading would equal
2617/3.785 = 691.5 gallons of domestic raw waste water.

Salvato says that average domestic water usage varies with
availability but lists per capita usage in 1975 as about 168 gallons
per day. So one liter of 70% nitric acid would be equal to about 4
days worth of normal nitrate loading.

I think the advice of trying to use the local household waste
program to dispose of the acid is the best idea for someone that is
not familiar with handling and safety. For me, I have avoided buying
any nitric acid because of the local minimun quanties and the fact
that I would need to buy more than I could use, therefore need to
dispose of some of it.

If I had to dispose of it, I would experiment a little diluting the
acid than neutralizing with household ammonia. I would determine how
much ammonia was needed by testing smaller measured quantities
determining when a drop of the dilute mixture did not make baking
soda foam. When a drop does not make the soda foam, I have determined
the proper proportions. (method is called titration) I start each
step by experimenting with small quantities to ensure that the
reaction did not get violent. The result would be ammonium nitrate,
a commercial fertilizer…(nowadays you need to show a drivers
license to buy it because it can be used by terrorists to make
explosives)

Once all of the acid were neutralized I would feed it to the compost
pile. The nature of compost piles is that they have a surplus of
carbon. The decomposition bacteria depend on the best carbon nitrogen
ration to get the pile hot and speed up decomposition. I would not
use washing soda or baking soda for the neutralization because the
sodium in those compounds tends to make clay in the soil sticky. Clay
properties are determined by the calcium/sodium ration…more hence
lime or gypsum breaks up heavy clay soils… Even though I love
numbers, this would be just too many numbers for my compost pile.)

I cannot recommend the chemistry method to anyone else…what you do
depends on how well you can take safety precautions etc. Strong acids
and strong bases should be approached with knowlege caution, and
respect; never by someone that is clumsy with such things.

I hope everyone forgives me for showing off my reference library.
This morning, I cracked open some old books that I haven’t look at
for awhile.

Howard Woods
Eagle Idaho