Gold Precipitation

Which is a better regent for precipitating Au from AR, Sodium Nitrite or Sodium Bisulfite and why? Thanks.

you havent tried any processes yet have you? if not, then dont do anything until you read Hoke's book "refining precious metal waste". you need to learn about what reagent does what.

sodium nitrate does not precipitate gold. SMB (sodium metabisulfite) is the preferred precipitant for gold on the forum.

dont do something that will endanger your self or someone else before you study what you want to do and how to do it.

Seconded.

Don't take offence but refining isn't a chuck it in a bucket add a few chemicals, leave it and go to the bar, come back drain it off and add another chemical and hey presto gold.
Take the advice offered and study and read Hoke until it makes sense,also read the safety section and be prepared to spend many hours doing yet more reading before you attempt any recoveries or refining.
If you have values sitting around they are safe unless you dissolve them and then can't recover them,take your time and you can be successful and that button will be yours.

I have read where sodium nitrite is used to precipitate gold and works something like copperas, and I also understand the solution should not be too high of an acid content (excess acid), I have never used it, so I really do not know any details.

I have used sodium bisulfite and sodium metabisulfite, and they work well, copperas (ferrous sulfate) also works well.

Geo, note, he asked about sodium nitrite NaNO2, not sodium nitrate NaNO3.

Hoke also mentioned the use of sodium nitrite to precipitate gold from aqua regia.

I agree 100% study Hokes book, it is your key to understanding the processes.

I was hoping that the Bisulfite precipitation would not be as fine a powder as the Sulfite.

Does Hokes 's book add more detail than Ammen?

Using Sodium Sulfite does require the solution to be free of Nitric and a ph of at least 5.5. If ph levels do not have to be as high with Sodium Bisulfite then that is another advantage. In addition, I do not know if the Nitrite produces the SO2 gas, which is desirable as the Bisulfite does.

It is in Hoke's book

Geo, he did say sodium nitrite and not nitrate. Sodium nitrite can be used to precipitate gold.

after re-reading i understand i mis-read.

PGM, i apologize, it happens sometimes when ive been up twenty hours.

Hoke page 56

That's ok Geo, ain't nobody perfect.

PGM-Au-Ag said:

I was hoping that the Bisulfite precipitation would not be as fine a powder as the Sulfite.

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How the gold comes down may be a function of the degree of concentration, although I'm not sure that's true. Here's why I say so.

I routinely re-processed all of my gold, and did so for years. I did it by repeating the aqua regia method, and used SO2 for precipitation. I routinely processed in lots that were approximately 75 ounces in size. The solution was generated such that I ended up with four four liter beakers, each containing, more or less, ¼ of the 75 ounces. The solution was evaporated to just one liter in volume, to which I'd add about three liters of ice, just prior to precipitation.

The gold from this procedure came down dense and blond (very pale in color) and would settle in just a minute or two. The only exception would be if the solution got too hot, and ceased precipitating. When that occurred, I'd add a little more ice, to cool the solution slightly, then commence precipitation. The solution, now quite dilute, would precipitate much finer particles. I can only speculate that it was because of being greatly diluted.

You may wish to give concentration a try, but, remember, precipitation with SO2 is an exothermic reaction, so if your solutions are too highly concentrated, precipitation will cease, just as it did for me.

Harold

please help me . i soaked some gold pins in nitric acid over night , then rinsed all the gold in water thoroughly before adding them to AR. i ended up with a lovely yellow solution and i really thought it was finally working out for me , but when i added the SMB , it went black then changed to atransperrent green.
i continued to add SMB but all it did was lighten in colour and no gold dropped.
so thismorning i added some aluminium and it smoked and changed to a dark brown solution and i see dark sandy dust on the bottom.
is that gold ? and why did my AR go green instead of dropping the gold ?

How did you neutralize nitric in your AR before adding SMB?
Here is your problem.

i didnt . i thought thats what SMB does.
so if i had heated the AR for about half an hour , then added hcl then heated again , would that be ok to then add SMB ?

goldpete,

Before doing anything more I suggest you study Hokes Book, other wise your just going to be stumbling from one mistake and mess and into the next mess, fumbling around looking for where all of your gold has disappeared to, after you dissolved it.

I feel if you do not do the studying before you begin your just wasting your gold and time.

You are looking for the evaporation process to remove excess nitric acid, you can find the process in Hokes book, (notice in her book she uses a steam table, which would not boil the solution while dispelling the free nitric acid from solution, you can use other heat sources as long as you can control the temperature, I imagine you also have an excess of SMB in this solution.

ive been watching so many videos on youtube and they all make it look so easy , and ive read so many foums . im tying to oganise all the info but it seems im confused somewhere along the line

Goldpete.
Forget the you tube videos for now. Most are fake or wrong, and the ones that are real should only be watched after you have built a working knowledge of the art of recovery and refining. Also from this point on forget reading any other forums or google searches. You have found the right place, that is as long as your willing to learn.

Use the search function on this forum to answer most of your questions.

Put your mess away safely, for now, and study your butt off. As long as you don't throw anything away your gold will still be there waiting on you.

There are much better ways to dissolve your gold foils. Ways that you don't have to rid the solution of free nitrates. Like HCL/CL (hydrochloric acid / bleach ) it will dissolve your recovered foils and all you will have to do is leave it alone for 24 hours to let the chlorine evaporate out before adding SMB.

Your on the right track, please stay on it. Study, and study more before asking questions, then when you have a question, ask it before you try anything. I did this and my first try at recovery and refining went text book perfect. It's all thanks to the members of this forum, the only place I get my information.

Can't wait to see that first button.

tek4g63 said:

Goldpete.
Forget the you tube videos for now. Most are fake or wrong, and the ones that are real should only be watched after you have built a working knowledge of the art of recovery and refining. Also from this point on forget reading any other forums or google searches. You have found the right place, that is as long as your willing to learn.

Use the search function on this forum to answer most of your questions.

Put your mess away safely, for now, and study your butt off. As long as you don't throw anything away your gold will still be there waiting on you.

There are much better ways to dissolve your gold foils. Ways that you don't have to rid the solution of free nitrates. Like HCL/CL (hydrochloric acid / bleach ) it will dissolve your recovered foils and all you will have to do is leave it alone for 24 hours to let the chlorine evaporate out before adding SMB.

Your on the right track, please stay on it. Study, and study more before asking questions, then when you have a question, ask it before you try anything. I did this and my first try at recovery and refining went text book perfect. It's all thanks to the members of this forum, the only place I get my information.

Can't wait to see that first button.

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thankyou so much for your help , and i will follow what you say to the letter. , i think i had a win today . cuz i put some aluminium into the aqua regia that i talked about before and it fizzled and smoked and turned a purplish colour , then i heated it till it reduced half its quantity , then i put HCL into it till it reached its original volume and it has returned to the deep yellow . im so excited ....... i kept heating it till it reduced by half its volume . so now i have about 100ml of deep yellow solution. what do i do now?

so now i have about 100ml of deep yellow solution. what do i do now?

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Put a cover over it and do your reading and studying. It will be much more beneficial to you if you find this answer out yourself rather than someone telling you what to do next. Your gold isn't going anywhere. Cool your jets and take your time to learn proper procedure. It's a lot better than messing up and then trying to figure out how to fix it. Listen to the advice given and you'll be on your way!

maynman1751 said:

so now i have about 100ml of deep yellow solution. what do i do now?

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Put a cover over it and do your reading and studying. It will be much more beneficial to you if you find this answer out yourself rather than someone telling you what to do next. Your gold isn't going anywhere. Cool your jets and take your time to learn proper procedure. It's a lot better than messing up and then trying to figure out how to fix it. Listen to the advice given and you'll be on your way!

Click to expand...

ok thanks .just out of curiousity ,did i do good returning the solution back to a deep yellow