How to seperate SN from curing salt mixture?

[nw7]

I guess many of us are anticipating more restrictions on selling pure SN to individuals. So, maybe it is a good idea to discuss alternative ways to obtain SN. I looked at the ingredients of some curing salts, and found that they contain %6.25 SN. That's 62.5g of SN per 1Kg of curing salt. It's good for 2-3 "SN drinks".

I searched for a way to separate SN from a mixture of SN and table salt (Sodium Chloride). And found this post (quoted below) http://www.sciencemadness.org/talk/viewthread.php?tid=11734#pid145461

I'm not good in chemistry. I don't really understand the method. Except, it uses the difference in solubility in water between SN and Sodium Chloride at different temperatures. So, can someone look into this method and validate it? Moreover, maybe adopt a method to separate the SN using regular home kitchen tools.

i have done this many times and it is relatively simple, the mixture was a 10%sodium nitrite, 90% sodium chloride. I will give an example for a 1kg mixture.
Place mixture into a column and run enough water through the column to dissolve all the sodium nitrite at room temp. This is 1000/815=1222ml, then add 10%, so around 1400ml.
You now have a solution of 1400ml water, 100g NaNO2 and around 350g (x1.4)=490g sodium chloride, its solubility in cold water.
Boil the solution down until the sodium nitrite has reached saturation at 100C, which would be around 100mL, but practically it will be closer to 200ml. At this stage you will have an enormous volume of sodium chloride suspended in the sodium chloride/sodium nitrite/water solution. Hot filter very quickly and at temperature.
Your solution now has ~200ml h20, 100g sodium nitrite and ~50g sodium chloride.
Chill to ~2C, the sodium chloride largely remains in solution the sodium nitrite will crystallize, this filtered gives you about 75g of your original sodium nitrite which can be re-crystallized from Methanol/water to give quite pure sodium nitrite.
The remaining solution should be kept and accumulated and re-concentrated.
When i did this some years back i used 10Kg salt at a time in a long column and was all very manageable. I was rather pleased something i figured out worked reasonably well as designed for once. Exploited is the fact the sodium chlorides solubility remains largely consistent over 100C solution temperature whereas the nitrites solubility doubles.
Good luck!

edit--i just found my notes and the curing salt was actually 12.5% nitrite, 87.5% choride, but the concept remains the same

 

[EternalSkies]

In my country it is almost impossible to get pure SN. But after googling around I found the same comment you found that made me realize you can somewhat easily with that/a similar process get 30g in a certain way. I found it hard to understand at first the tried to get an understanding of everything that person wrote

I have refined the process myself in theory to make sure it works well even if there is losses in the process and stuff. I even wrote a guide and explanatory text. But I don't want to post it
I will try it myself probably as soon as I can. Although I plan on using inert gas

In theory you will always lose more sodium chloride than sodium nitrite when disolving curing salt into water.