# nitric acid & SnCl2



## lala14 (Jan 11, 2010)

just wondering if this have ever happen to yall an if has can it be use to strip the gold plated items an not hurt other metals so this is what i did i had some pins that had gold plate in them wish this was just a test so 1mil of nitric an 2 drops of SnCl2 WELL the pins wer all ready on nitric nothing was going on ok i said :| i added 2 drops of SnCl2 an behold reaction but :shock: the gold was gone an the reaction stop on the bottom i still had pin same amont i put in im hopping that the nitric should of eat up nop so i went ahead an filter the solution was mi filter for just in case well i went ahed an teste for gold :lol: yea the gold was in the solution i was wow well mi question to yall why in the the word dint the pins disolve what the hell did i do or did i dicover onther way to strip the gold an save other pm :!: :!: brain storm i will post pic as soon as i can :mrgreen:


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## butcher (Jan 11, 2010)

sound like you just made a little bit of aqua regia with high nitric content.


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## lala14 (Jan 11, 2010)

butcher said:


> sound like you just made a little bit of aqua regia with high nitric content.


saound like AR but what about the other metals well see i end up doing it againbut thistime warm nitric an same with SnCl2 well it did eat up everything but the first time it was at cold temp wish its cold right know in texas an it only eat up the gold hm going to doit again i want answers one more thing yes the nitric aside is 70% an mi HCL IS muarric acide concreat cleaner with 95%tin 5%lead SnCl2


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## butcher (Jan 11, 2010)

lala, this is not the best way, using aqua regia on base metals with gold, especially if you are new to this, getting back your gold will be harder and less pure, since you have the nitric, use this to eliminate the base metals first, since you have already done this on this batch,
how much nitric to Hcl do you think you have in solution?

if HCL was high content and HNO3 (nitric) was very low in content, you can leave the solution in with the copper and let it use up your nitric, driving of NO2 with some heat if needed, letting the gold in solution be replaced with copper once nitric all used up, gold as impure brown powder.

but if nitric in solution is high it will need to be driven out with evaporation to syrup and HCl to keep wet three time's to eliminate the nitric, and if you had any lead on you pins this will also complicate things.

I understand you are excited to get gold, and can not hardly wait, but if you spend time and study this more, follow the methods that are proven to work, you, in the end you will get more gold, purer gold, less time wasted trying to get out of problems and trying to find out what went wrong. if you dont, you may learn, but it will be the hard way, later kicking yourself in the hind end. saying Ole man when I first started this if I had learned the process well before I started that wonderful batch of material processed, I could have gotten all the gold out of it easier, not waisting all that time, and I would not have that gold mixed in with my bucket of waste materials lost for good, some time studing can really be rewarding.


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## lala14 (Jan 11, 2010)

butcher said:


> lala, this is not the best way, using aqua regia on base metals with gold, especially if you are new to this, getting back your gold will be harder and less pure, since you have the nitric, use this to eliminate the base metals first, since you have already done this on this batch,
> how much nitric to Hcl do you think you have in solution?
> 
> if HCL was high content and HNO3 (nitric) was very low in content, you can leave the solution in with the copper and let it use up your nitric, driving of NO2 with some heat if needed, letting the gold in solution be replaced with copper once nitric all used up, gold as impure brown powder.
> ...


not alot that i use it was less then 10mil to 2 1/2mill yes i understad i should of use the nitric first i see what you mean thanks for your help butcher


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## butcher (Jan 11, 2010)

we will help you out here, I have a feeling you will need some later with this batch, keep us posted how your doing with it.

with high gade heavy gold plated pins, nitric may have a hard time with them, nitric can have a hard time trying to get through the gold layer.
it will take a little time and strong hands, good lineman wire plyers, I cut them to small pieces, snipping off both ends then cut pin in small pieces, this way copper is exposed to acid and surface area reduced, and the oxidizer bubbles dont have to go deep into a cave of gold to get to the copper. other pins with less gold this is not needed.


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## lala14 (Jan 12, 2010)

butcher said:


> we will help you out here, I have a feeling you will need some later with this batch, keep us posted how your doing with it.
> 
> with high gade heavy gold plated pins, nitric may have a hard time with them, nitric can have a hard time trying to get through the gold layer.
> it will take a little time and strong hands, good lineman wire plyers, I cut them to small pieces, snipping off both ends then cut pin in small pieces, this way copper is exposed to acid and surface area reduced, and the oxidizer bubbles dont have to go deep into a cave of gold to get to the copper. other pins with less gold this is not needed.


butcher so after just using nitric i got gold foils only an alot why dint the gold get eaten i was hoping to see brown dust my guess is that know i disolve this in aucl :mrgreen:


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## butcher (Jan 12, 2010)

after nitric, and if just gold foils, be sure there is not chunks of copper, and foils are free from base metals,if you have undissolved base metals you will dissolve these in the next step and then your solutions will contain these making your gold less pure.

You can use Aqua Regia, 
or hydrochloric acid and bleach, to dissolve the gold.

With aqua regia, nitric acid will need to be eliminated before precipitating the gold as brown powder, dont make the mistake of using too much acid, and if you only add small amounts of nitric as needed to get the gold dissolved,with low heat, it will be easier to eliminate nitric later,a trick is to leave a small amount of gold undissolved, it will usually dissolve later when you boil down solution to eliminate the nitric through evaporation.

with HCl/Bleach you will not have to evaporate the nitric later, and if chlorine is not strong in solution a little heat will drive off excess, also bleach is cheaper than nitric for me.


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## Richard36 (Jan 12, 2010)

Hello lala14,

If I understand correctly, you should now dissolve those foils in a mixture of 4 prts Muriatic / 1 prt Clorox bleach.
Once the gold foils have dissolved, Add sodium meta bisulfite to precipitate the gold as a brown powder. Filter the solution to recover the gold. Let this dry, and mix it at a ratio of 1 prt gold precipitate to 3 prts borax, and melt it with a torch to produce the familiar yellow metal.

Those foils could also be dissolved into Aqua regia, which is a mixture of 4 prts Muriatic acid / 1 prt Nitric acid.
Once dissolved, boil down the solution to 1/3 of its original volume, add 1/3 the solutions original volume of Sulfuric acid, and an eqqual amount of Muriatic, so that the solution is again equal in volume to what you had before you boiled it down.

Boil this down to 1/3 its volume, add some more Murriatic acid so that you again have solution equal to the original volume, and boil down again.

After this boil down, add enough distilled water to equal the solutions original volume, and add some sodium meta bisulfite to the solution to precipitate the gold as a brown powder. Filter the solution, let the precipitate dry, and melt it with the Gold Precipitate to Borax ratio metioned above.

I hope that this has been helpful.

Sincerely; Rick.


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## lala14 (Jan 12, 2010)

Richard36 said:


> Hello lala14,
> 
> If I understand correctly, you should now dissolve those foils in a mixture of 4 prts Muriatic / 1 prt Clorox bleach.
> Once the gold foils have dissolved, Add sodium meta bisulfite to precipitate the gold as a brown powder. Filter the solution to recover the gold. Let this dry, and mix it at a ratio of 1 prt gold precipitate to 3 prts borax, and melt it with a torch to produce the familiar yellow metal.
> ...


thanks rick i actuly started the prosse of AUlc IM in the house right know im going to wait till all the foils are dissolved so your teling me that i dont add any water to aucl at all just smb an see the gold drop is this correct :mrgreen: 
also i usto do AR nutraliz with urea an add SMB wish was expensive at first till i found out this site know most chemical are from mi job


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## Richard36 (Jan 12, 2010)

lala14 said:


> thanks rick i actuly started the prosse of AUlc IM in the house right know im going to wait till all the foils are dissolved so your teling me that i dont add any water to aucl at all just smb an see the gold drop is this correct :mrgreen:
> also i usto do AR nutraliz with urea an add SMB wish was expensive at first till i found out this site know most chemical are from mi job



You are correct. 

Dissolve your foils in the acid/clorox, then add the sodium meta bisulfite to precipitae your gold.
If someone with better understanding of the acid/clorox method says to do something other than what I wrote, then follow their advice.

I am far more experienced with the Aqua Regia method for refining foils.

Sincerely; Rick. "The Rock Man".


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## butcher (Jan 12, 2010)

Good post Rockman, 
I think before he tries to melt and gold he precipitates we need to know the colors of his solutions, before precipitation, this will help us to determine somewhat his purity, and if he will need refining or or if a good wash (acids and waters) of the precipitated gold will do the job, Rick lets work together to help him get fine gold, gold pure enough he wont need borax,except to let the pure gold slide in the melting dish.

LaLa since this is all new, and a slight language barrier lets just take it one small step at a time, rockman and I will help.


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## Richard36 (Jan 12, 2010)

butcher said:


> Good post Rockman,
> I think before he tries to melt and gold he precipitates we need to know the colors of his solutions, before precipitation, this will help us to determine somewhat his purity, and if he will need refining or or if a good wash (acids and waters) of the precipitated gold will do the job, Rick lets work together to help him get fine gold, gold pure enough he wont need borax,except to let the pure gold slide in the melting dish.
> 
> LaLa since this is all new, and a slight language barrier lets just take it one small step at a time, rockman and I will help.



Fair enough.
I am willing to help, if the questions are asked,
Provided that I have an answer. lol!

Sincerely; Rick. "The Rock Man".


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## lala14 (Jan 12, 2010)

butcher said:


> Good post Rockman,
> I think before he tries to melt and gold he precipitates we need to know the colors of his solutions, before precipitation, this will help us to determine somewhat his purity, and if he will need refining or or if a good wash (acids and waters) of the precipitated gold will do the job, Rick lets work together to help him get fine gold, gold pure enough he wont need borax,except to let the pure gold slide in the melting dish.
> 
> LaLa since this is all new, and a slight language barrier lets just take it one small step at a time, rockman and I will help.


ok guy i sulotion is about 40mil an its kinda of yellow an a hint of green i think i still have copper what the next step


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## lala14 (Jan 12, 2010)

rick & butcher i also have onother beker that i did aucl an it looks more like a dark emarl with a littel hint of yellow i think something whent wrong on this one


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## Richard36 (Jan 12, 2010)

lala14 said:


> ok guy i sulotion is about 40mil an its kinda of yellow an a hint of green i think i still have copper what the next step. rick & butcher i also have onother beker that i did aucl an it looks more like a dark emarl with a littel hint of yellow i think something whent wrong on this one



Ok, If it is showing green, it still has some copper contamination.
Gold Chloride (AuCl) Should be a transparent yellow solution.
So at this point, let it continue to dissolve untill no metallic material is left in your acid /clorox solution.
Once dissolved, precipitate your gold with SMB.
It may well still contain traces of Copper, but very little.
Your gold will still be quite pure enough to sell.

Sincererly; Rick. "The rock Man".


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## lala14 (Jan 12, 2010)

Richard36 said:


> lala14 said:
> 
> 
> > ok guy i sulotion is about 40mil an its kinda of yellow an a hint of green i think i still have copper what the next step. rick & butcher i also have onother beker that i did aucl an it looks more like a dark emarl with a littel hint of yellow i think something whent wrong on this one
> ...


i went ahead an tested thir is gold know just put mi smb i had alot of fume smell like clorox but strung i stird it but im getting nothing should i leave alone or add mor smb


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## butcher (Jan 12, 2010)

Looks like I'm a little late on posting I type very slow but read this anyway.
Before answer, did pins have lead? If so we will want a couple of drops of sulfuric acid to make lead fall out as lead sulfate, and lets be sure of chemicals used, if HCL/ bleach, we cannot have free chlorine still in solution, heat or time in the sun will drive off extra chlorine, if you give it a boil you may see salt form in bottom, add enough water to disolve salt, or if you just let it sit in hot sun for a day, check and see if you smell bleach.

If Aqua regia we we need to eliminate nitric with evaporation technique.
since you used nitric earlier there may be some nitric that came with foils,
I would normally cook this from foils before dissolving in HCl/Bleach, if you rinsed foils this will be minimum, and your sulfite should overcome it.

while you are doing this we will need some SnCL2, to test for gold in solution If you need to make up some.

you will also need a sulfite, sodium metabisulfite, or ferrous sulfate,
do you have any of these? 

After free chlorine is no longer a problem. add SMB (or your choice of precipitant),if SMB I dissolve it in warm water to form saturated solution, add small portions at a time adding not much more than the gold you expect, stirring well, you should smell SO2 gas (stink) solution should start to turn brown forming gold powders, let sit overnight, we will test the solution for gold with stannous cloride test, to determine if all gold precipitated.

since you have some green (some copper)we will do this again re-refine dissolving the precipitated powder in a little bit this time, only as much as needed HCl/bleach and precipitate again this will make your gold very fine, leaving the copper behind, these brown gold powder's will need a good wash we will get to that later. if you are waiting on somethig and have time read Harolds post on washing the Gold powder's, and look at his bowl of fine gold, just be careful it will make your mouth drool.


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## lala14 (Jan 12, 2010)

butcher dint find Harolds post can you help also im going to wait till morning so i can what im doing thanks for all the help 
jesse 8)


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## butcher (Jan 12, 2010)

Jesse, good Idea sounds like you are going too fast here, let solution sit overnight read what was posted, you may have too much chlorine , or even nitric in solution, if you dont see powders in the morning a boil will probably be needed,I will see if I can search for Harolds post he made several on washing the gold powders, if you really are going to get good at this following his advice reading Hokes book and harolds and others posts will be a big help.

once you understand then go for the gold.


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## butcher (Jan 12, 2010)

There are NO shortcuts. If you want pure gold, you MUST follow accepted practice. 
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=37&t=2431&p=20949&hilit=harold+post+gold+wash#p20949


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## Richard36 (Jan 12, 2010)

Thanks Butcher.

I am new to this acid/clorox method myself. 
I Fire Refine my foils with The U.S. Mint's Gold flux Formula as a first choice, and with the Aqua Regia method as a second.

Sincerely; Rick. "The Rock Man".


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## butcher (Jan 13, 2010)

Rick, this flux formula is there more than just borax in it? it sounds as though you try to clean up your gold through a melt, which will work somewhat if the flux mix can oxidize base metals and draw them into slag, and can help to improve gold quality if done properly, if done improperly there is also chance of loosing gold, melt temperature and flux can play a big role, I have dabbled in it but my skills lack in this area.when working with metals that have been refined before such as in electronic scrap, I feel acid seperation would be best if done properly, (or melting dore and electrorefining), and if steps taken to eliminate the base metals, a fairly pure gold solution can be produced with electronics there are metals that will cause trouble in certain steps of the process. and gold (or other metal) precipitated from the first recovery process may need re-refined again, sometimes more than twice, one thing after recovery, refining each additional time is much easier, and product much purer, and if we just spend a little more time on this with good work practice our final product is easier to melt and flux is not needed, and in my opinion more valueble and rewarding, if I just wanted to sell gold fast I think just melting to dore bars that look like copper and selling them to an refiner would be easier, and if a person was working with very large volume that may be a better way, refiner may be able to skim more from you, but your dealing in volume, when you deal in small volume, pure product would be of higher value, and if a person had a jeweley made from it the value can even be higher, there is not much to say if a person can learn to refine he could also learn to make jewelry from his product, if he had a mind to.some of us work with little volume, and good scrap seems hard to come by, so refining to a very pure product only makes sense to me, it is really not that hard once we learn and if we follow guidence of some fellow forum members, so willing to teach us their skills. of course all to his own and each of us has to make a decision of how far we take our product, one miner may find just selling his concentrated ore in high volume to be more profitable and rewarding, and the next miner may want to melt his ore to yeller impure metal, and one may want pure gold brick, to each to his own. since this is the gold refining forum I presume the person asking the question is not just asking how to recover his gold but to refine it the best he can, so I try to gear my answer towards that goal, otherwise I may tell him to precipitate his gold with copper, flux melt assay sell to refiner, who knows he may get just as much money for it with an honest refiner.


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