If you need Nitric for anything except for silver, you can make Laser Steve's cold nitric recipe. I've been using it for many years, It's only 35 to 40% concentration.... But you need the water for the reactions anyway.
"Reaction #1
1) Bring 100 mL distilled H2O to a rolling boil (100 C)
2) Remove the H2O from the heat
3) Add 170 gm of NaNO3 into the 100 mL of hot distilled H2O with constant stirring until fully dissolved
4) Add 56 ml 98% H2SO4 in small portions to the niter solution with stirring, DO NOT let the solution boil
5) Let solution cool to room temperature (DO NOT skip this step or your reaction vessel may shatter!!)
6) Place reaction vessel into freezer or salted ice water bath until the solution temperature reaches -5 C
7) Let solution set for 30 minutes at -5 C
8} Pour or siphon off the liquid nitric acid while cold"
I skip the freezing part and just let it come to room temperature and filter off the remaining salts. Also, I think you can use 202 gm of Potassium nitrate instead of 170 gm Sodium nitrate.
