# Sodium Bisulfate vs Sodium Bisulfite



## bob2064 (Sep 1, 2012)

Hello everyone. I have a question about precipitating gold.

I am not a chemist, and i was wondering if the Bisulfate can be used instead of Bisulfite to do this process?

I used the AP method to remove the foils from my scrap, and this worked out nice. I had a lot of gold foils. I rinsed them, cleaned them, then dissolved them in HCL-CL. Now I need the dust. Where I live pool supply stores are abundant and i got some Sodium Bisulfate for the process not paying much attention to the one letter difference. I used this to try to get the gold to precipitate and the reactions I expected did not happen. Only then did I pay attention to the spelling.

So my question is, can I use this Sodium Bisulfate, and if I can, what reactions i would expect and how long it would take to get the desired reaction. 

If I can't, where can I find the sodium bisulfite? I am looking for a brick and mortar store that has it....preferably a chain store that is in every city. I have found plenty of places online to get it. Also the closest home brew store to me is too far of a drive. 

Is there anything else that can be used to precipitate the gold that can be found easily. For instance at a grocery store?

Also one last question. Is my solution now no good if the Bisulfate cant be used to precipitate.

Thanks for any information that can help me out


----------



## philddreamer (Sep 1, 2012)

Bob, you need bisulFITE. 
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=48&t=10457&p=113105&hilit=bisulfite#p113105
Take care and be safe!
Phil


----------



## bob2064 (Sep 1, 2012)

Thanks Phil....much appreciated.
One letter can change whole make up...Will be sure to pay close attention to what I am actually buying.


----------



## Golddigger Greg (Sep 1, 2012)

I found a chemical supplier that specialized in water treatment that had SMB, but only in 25KG bags. I have enough to last a few years there, I think! I just have to re-package it in smaller lots to keep it that long. I seem to recall a post that said it will degrade when exposed to air.


----------



## trashmaster (Sep 6, 2012)

Home depot has it as STUMP OUT .....'';;;


----------



## lazersteve (Sep 6, 2012)

Make sure you buy Bonide brand stump out as others are nitrate based.

Steve


----------



## kurt (Sep 7, 2012)

beer & wine making supply store should also have the the right SMB

Kurt


----------



## galenrog (Sep 7, 2012)

Steve is absolutely right. I would add that anyone using any stump rot product should check the ingredients before purchase. When in doubt, ask.

Although a more expensive route, the SMB sold at many home brew supply stores (as suggested by kurt) is not laced with any additives and may be easier to find (it was for me, after reading labels on a mountain of different stump rot products).


----------



## nōnāgintā trēs (Dec 6, 2012)

I once bought something called Pyrosulfit Na2S2O3. Very similar but nothing dropped. I did give off a nasty sulfer dioxide smell!!


----------



## Geo (Dec 6, 2012)

nōnāgintā trēs said:


> I once bought something called Pyrosulfit Na2S2O3. Very similar but nothing dropped. I did give off a nasty sulfer dioxide smell!!



did you test to make sure you had gold in solution?


----------



## FrugalRefiner (Dec 6, 2012)

nōnāgintā trēs said:


> I did give off a nasty sulfer dioxide smell!!


According to my wife, I've been known to give off that smell as well. :shock: 

Welcome to the forum!

Dave


----------



## nōnāgintā trēs (Dec 11, 2012)

HA, I meant It gave of a smell but thats my bad :lol: I deffinatly had gold in the solution but that pyrosultite never worked for me. It was I think 20 euros ($30) a kilo (2LBs). Never again!! Now I pay 52euros ($75) for Sigma SMB. It's expensive but worth it to me!


----------



## Geo (Dec 11, 2012)

Latin for 93, ive use sodium sulfite before. it just takes a little more for the reaction to occur. i too will pay more for SMB though. it seems to be a little bit cleaner.


----------



## Tino (Jun 4, 2014)

Hello everyone , I just made the same mistake bob did a couple of years ago. I viewed all of the answers and see that it must be the bisulfite. However I did not see any answers pertaining to part of his original question concerning if the solution is no good now. Surely there has to be corrective measure wether simple or not I have no idea. But I now have my gold chloride solution from acid and bleach saturated with sodium bisulfate. I actually kept adding it since there was nothing happening and put in A ton of it probably 30 to 40 % of the volume has increased . I instinctively started adding copper to see if that would help start a reaction but it doesn't even seem to be digesting the copper now. What do I do? I have all the gold I have been collecting for months dissolved in that solution and I am willing to do whatever it takes to get my gold out of that solution. Can anyone help?


----------



## butcher (Jun 4, 2014)

Sodium bisulfate NaHSO4, can act similar to sulfuric acid in many chemical reactions, it can give up it hydrogen fairly easy, thus forming sodium sulfate in solution Na2SO4, a sodium salt of sulfuric acid.

Sodium bisulfate NaHSO4and sodium chloride NaCl (table salt), can form hydrochloric acid HCl in a solution of sodium sulfate Na2SO4.

NaHSO4 + NaCl --> Na2SO4 + HCl
unless distilled to gas of the HCl gas and condensing it (there really would not be a reaction, as both of the above products would just be in solution together.

Sodium bisulfate NaHSO4, can be made with a chloride salt like NaCl and sulfuric acid, here again we get HCl in solution, which can be distilled off from the sodium bisulfate solution.
Several of the metal chloride will react in a similar manner.

NaCl + H2SO4 --> NaHSO4 + HCl

Now to the question, sodium bisulfate will not precipitate gold from solution.
We can use sodium sulfite Na2SO3 to precipitate gold from a gold chloride solution AuCl3.
Here is an equation of hydrochloric acid HCL and sodium sulfite Na2SO3, the products from this reaction is sodium chloride salt NaCl and sulfur dioxide gas SO2 (g) in a solution of water H2O.
Na2SO3 + 2HCl --> 2NaCl + SO2 (g) + H2O
It is basically this sulfur dioxide gas that is a precipitant for gold from solution.
(Which you do not get (SO2 gas with a reaction from a sulfate salt in a solution of gold).


Basically a little bisulfate in your gold solution would do no harm it could act similar to sulfuric acid precipitating lead as a sulfate, it would just stay in solution with your gold, not really reacting.

But adding large amounts of any chemical is not a good thing, especially if it not the chemical you needed to add to get the gold to precipitate.

Now at this point you have a possibly acidic mixture of sulfates, some chlorides and a little bit of gold in solution (depending on how you worked possibly other contaminates or base metals), and you wish to try and recover the gold.

I can see several possible solutions to this problem.

Acidify (if solution is not already highly acidic with HCl or H2SO4 and cement the gold using a large chunk of clean copper.

Or

Distill off the HCl (chlorides from the gold and solution), by adding some H2SO4, being sure not to let salts form when cooling keeping enough H2SO4 in solution and also dissolving the Na2SO4 or base metal salts with boiling hot water before solution cools, the gold will not be soluble in this solution and would precipitate once its chloride bond was broken from the chloride bonds, during the evaporation of the hydrochloric acid gases.

Or

Evaporate solution to salts, lower heat as it gets to syrup to prevent splashing from popping bubbles of steam and gases, heat till dry, raise heat (at this point it may again form a syrup and need heat controlled because of stem and gases bubbling), heat until dry again, (this will drive off chlorides), cool the sulfate cake, crush to powder, (an incineration of the crushed powder would not hurt a thing here and may help improve the product if this was a contaminated solution to begin with), and dissolve in boiling water, once the salts are dissolved letting the powders settle, leaving you, your gold powder to refine.
Also if this was a contaminated gold solution to begin with, a boiling hot wash in HCl after the incineration can help if base metals and tin were involved, before the boiling hot water washes (give time for powders to settle well before decanting (I normally try to decant solutions as warm as possible, this can help with solution which contain lead chloride, or where warm or hot solutions can hold more salts normally than a cool or cold solution will), (the gold may be fine powder black or brown, and I am not sure how much you had in solution to begin with...

Or

Put this solution in a safe place, for storage labeling it, and spend some time studying and getting acquainted, Hokes book is a great place to begin, this way you can learn to recover gold, and refine it without endlessly trying to get gold out of problem solutions, and if you do run into a problem you can just search your brain for ways to deal with it...


----------



## searcher1x (Nov 14, 2015)

butcher said:


> Evaporate solution to salts, lower heat as it gets to syrup to prevent splashing from popping bubbles of steam and gases, heat till dry, raise heat (at this point it may again form a syrup and need heat controlled because of stem and gases bubbling), heat until dry again, (this will drive off chlorides), cool the sulfate cake, crush to powder, (an incineration of the crushed powder would not hurt a thing here and may help improve the product if this was a contaminated solution to begin with), and dissolve in boiling water, once the salts are dissolved letting the powders settle, leaving you, your gold powder to refine.
> Also if this was a contaminated gold solution to begin with, a boiling hot wash in HCl after the incineration can help if base metals and tin were involved, before the boiling hot water washes (give time for powders to settle well before decanting (I normally try to decant solutions as warm as possible, this can help with solution which contain lead chloride, or where warm or hot solutions can hold more salts normally than a cool or cold solution will), (the gold may be fine powder black or brown, and I am not sure how much you had in solution to begin with....



I made a similar mistake a couple of weeks back. I added SMB to solution to drop gold but did not have very much and ran out before gold dropped. It was late so I figured to pick-up some the next day..

To make a long story short I was not paying attention and picked up Sodium bisulfate instead. Added quit a bit before I caught the error. Thought I would try your suggestion and put the solution on heat for several hours. End of day I had a long way to got so I put the container aside uncovered and tot set until I decided to get back to it.

That was a week ago. Today I noticed that there was some sort of crystal growing in the solution on the bottom of the container. The crystals are long (actually go from one side of container to the other side) and flat, about 1" wide. There are 3 or 4 of them growing and they criss-cross each other in the middle. Any ideal what they are?


----------



## Anonymous (Nov 14, 2015)

If you actually read the post above yours Searcher you will find the chemistry behind your problem answered 8)


----------



## searcher1x (Nov 14, 2015)

spaceships said:


> If you actually read the post above yours Searcher you will find the chemistry behind your problem answered 8)



I did read it, twice. Actually i've read the whole thread but there is no mention of any crystal growth that I could find. I've also did a search of the forum for the crystals and can't find anything. Granted, I probably have not figured out how to use the forum search correctly yet, but I have been looking for an answer.


----------



## Chimera (Feb 10, 2016)

Hi dear friends

Can someone tell me how many SMB i have to put with how many AR to precept gold please?


Thanks a lot.


----------



## jason_recliner (Feb 10, 2016)

Assuming you don't have any free nitric, or very little:

How much gold do you believe is in your AR?
Based on limited information, I would start with about 80% of that, by weight, then add more SMB in small increments until all the gold has dropped. If you end up at around 100-120%, that would not be an unrealistic final value.

Stannous Chloride Testing will tell you when you have dropped it all.


----------

