SSN - Which Salt?

[Gratilla]

Which salt is best for making SSN (Saturated Saline Nitric acid leach)?

1) Pure (unidodized) NaCl,
2) Iodized table salt (usually also includes an anti-caking agent),
3) Sea salt (NaCl plus Ca, Mg salts etc),
4) Rock Salt (similar to/same as Sea Salt?).

Or doesn't it matter?

The "standard" recipe calls for (uniodized) Rock Salt, but don't the impurities detract from the leaching reaction? The standard recipe also inconsistently warns (without explanation) against iodized table salt, but also states that SSN "can be enhanced with addition of a small amount of iodine" - again without explanation. From the language of the various sites that SSN recipes appear, it seems that all were copied (plagiarized?) from one original location without a full understanding.

BTW, when I do a search for SSN I get the "No suitable matches were found." response; similarly with BDG, DBC, etc. I'm guessing that this is because of a minimum character count (4?). SSN is similarly ignored as part of multiple words (ie +SSN +saturated +nitric), so I tried to outsmart the S/W with "SSN " and " SSN" ie with embedded spaces, but the S/W is obviously smarter than I am. :roll:

No problem with BDG and DBC as the full words can be used, but SSN ...

 

[Geo]

not by much or at least enough to make a difference. use rock salt and filter it after its dissolved.

 

[NobleMetalWorks]

You are not going to want to use salt with Iodine in it.

As Geo suggested, the rock salt is probably your best bet.

Scott

 

[Gratilla]

Hmmm, rock salt is the only one I don't have (easy) access to.

In the past I used sea salt; it's easily the cheapest here - by the sack, but it also has a lot of gunk in it. Even after filtering, it's still a bit cloudy. For experimenting, this wasn't a problem, but I now want to "step up the action" and any significant differences might be of interest.

No iodine, so that leaves sea salt (cheap) and pure NaCl. Any problems with the former?

 

[NobleMetalWorks]

You can use regular salt you purchase in the store, just so long as it's not iodized. Sea salt has a lot more than just the junk you can see in it, but if using small quantities it might not affect your leach solution in a negative way, I'm just not sure. I can tell you this however, sea water/salt is a soup of all kinds of trace elements and minerals.

Scott

 

[Gratilla]

Normally I'd use clean industrial grade chemicals (and the pure industrial NaCl, above, is not ridiculously more expensive by the sack than sea salt). But I can't help wondering if the first person to mention rock salt had a valid reason to do so??? Maybe the impurities act as a catalyst or something. Unless someone who's "been there, done that" is willing to share, I guess I'll go with Pure NaCl and then do a comparison somewhere down the line. Thanks.

BTW, a friend has recently got his license for (legal) small/medium scale (carbon-in-pulp) cyanidation. I plan to do some small parallel SSN leaching and Butyl Diglyme solvent extraction - first for a quantitative comparison, but also to see if we have any PGMs in our local ores. Does anyone have any hands-on experience (of SSN leaching of ores) or opinions?

 

[etack]

why do it at all? This seems like a huge waist of time. If you want to add Cl to your nitric add HCl and keep out the Na. Just add a little to it.

Eric

 

[Geo]

Eric, i know it seems kind of contrary but its a widely accepted process. just like any process, it has its pros and cons. its been discussed on the forum at least a dozen times since ive been here.

 

[etack]

Yeah I know I've read those post too, and every time I ask my self why!!!

NaCl has great used boiling eggs, making ribs, curing meat, melting snow, killing grass just to name a few but not in refining for any real process. Not even in converting silver nitrate to silver chloride. Just use HCl its faster and cleaner.

But you will do what you will. 8)

Eric

 

[Gratilla]

Why? Reasonable question. Who'da thought that (7 parts) Sat Salt Soln + (1 part) Nitric Acid could dissolve gold? Surprisingly it does - and it does it fast, particularly at higher temps. (I'm a few degrees south of the equator [av temp 32deg C +/-] so have no problem setting up a convection current driven solar heated system. I've regularly had temps > 70degs C.) In addition it dissolves the PGMs better than AR, in addition to all the junk metals. But if you're using BDG for solvent extraction, the latter aren't a major problem.

My opinion as to why, FWIW:
1) Cost: 7 parts aqueous sat NaCl soln + 1 part HNO3 is much cheaper than 3 (or 4) parts HCl + 1 part HNO3, making it practical for leaching ores.
2) Solvent Extraction: SSN produces a chloride so no (major) problem extracting with BDG. Solvents for gold cyanides are still at an early stage (ie not as efficient as BDG).
3) There was something else, but I forget. <s>
Oh yes, the PGMs. It's about the only practical leach for mass ores that dissolves the PGMs.

 

[Gratilla]

BTW, when I do a search for SSN I get the "No suitable matches were found." response; similarly with BDG, DBC, etc. I'm guessing that this is because of a minimum character count (4?). SSN is similarly ignored as part of multiple words (ie +SSN +saturated +nitric), so I tried to outsmart the S/W with "SSN " and " SSN" ie with embedded spaces, but the S/W is obviously smarter than I am. :roll:

No problem with BDG and DBC as the full words can be used, but SSN ...

BTW, I've just read other threads where the same (3-letter search) problem has been mentioned - but without resolution. Would it be possible to get this fixed? I know it's "good form" for a full expansion to accompany the first time an abbreviation is used, so a full-word search would get the same hits - in theory. But (particularly more experienced) posters tend to forget and these "abbreviated posts" more often than not are the more interesting posts. Anyway, just saying.

 

[Gratilla]

Wow!

I just did a google on "ssn saturated salt nitric" and this thread came in at no 2, right below Lashley's definitive doc on ssn on scribd.

Wow! Is this the first step to going viral and millions in advertising fees? Look out Gangnam/Psy, hold on to your britches.


BTW, not to waste a decent bump, :mrgreen:, could I politely ask the moderators to look into "fixing" the Search for TLA's (Three Letter Algorithms). I find that posts using TLA's tend to be more informative than average. Maybe because the more experienced members use them more often, assuming that the rest of us know what they mean. (I do now.) BTW, did I say, "please".

 

[Ali]

Why? Reasonable question. Who'da thought that (7 parts) Sat Salt Soln + (1 part) Nitric Acid could dissolve gold? Surprisingly it does - and it does it fast, particularly at higher temps. (I'm a few degrees south of the equator [av temp 32deg C +/-] so have no problem setting up a convection current driven solar heated system. I've regularly had temps > 70degs C.) In addition it dissolves the PGMs better than AR, in addition to all the junk metals. But if you're using BDG for solvent extraction, the latter aren't a major problem.

My opinion as to why, FWIW:
1) Cost: 7 parts aqueous sat NaCl soln + 1 part HNO3 is much cheaper than 3 (or 4) parts HCl + 1 part HNO3, making it practical for leaching ores.
2) Solvent Extraction: SSN produces a chloride so no (major) problem extracting with BDG. Solvents for gold cyanides are still at an early stage (ie not as efficient as BDG).
3) There was something else, but I forget. <s>
Oh yes, the PGMs. It's about the only practical leach for mass ores that dissolves the PGMs.

why not using SMB to precipitate gold?..I'm also intending to use this leach for tailing re-processing.

 

[lazersteve]

BTW, not to waste a decent bump, :mrgreen:, could I politely ask the moderators to look into "fixing" the Search for TLA's (Three Letter Algorithms). I find that posts using TLA's tend to be more informative than average. Maybe because the more experienced members use them more often, assuming that the rest of us know what they mean. (I do now.) BTW, did I say, "please".

The fix has been around for many years: Google.

Or you can use my Google Powdered search page for the forum, SSN produced 75 results in 0.46 seconds.

Link below signature and you'll find zero ads on my website !

Steve

 

[rusty]

Hmmm, rock salt is the only one I don't have (easy) access to.

In the past I used sea salt; it's easily the cheapest here - by the sack, but it also has a lot of gunk in it. Even after filtering, it's still a bit cloudy. For experimenting, this wasn't a problem, but I now want to "step up the action" and any significant differences might be of interest.

No iodine, so that leaves sea salt (cheap) and pure NaCl. Any problems with the former?

Water softener salt with addition of bromine.

 

[bmgold2]

Everybody says "Don't use iodized salt" but I can't find a single explanation as to why. Maybe nobody really knows and are just repeating what they have always heard.

Can anyone tell me why you shouldn't use iodized salt?

bmgold2

 

[Lou]

Iodide in small quantities is a very effective precipitant for Pd.

Most PGMs become less soluble as you go from Cl>Br>I ligand.

 

[bmgold2]

Thanks Lou. If I understand you right, regular iodized table salt would be OK to use if you don't have (or don't care to extract) any PGM. Just telling someone not to use something doesn't help much unless you also tell them why.

bmgold2

 

[Lou]

Shouldn't hurt, it's only a trace.

 

[niteliteone]

Shouldn't hurt, it's only a trace.

Thank You Lou.
I am researching this topic as well and wondered what negatives iodine posed to this process.