# neutralize AQUA REGIA



## k_fassi (Nov 23, 2015)

I saw before someone neutralize AQUA REGIA with Sodium hydroxide do you think it is better to use something else.

and to drop gold he was use hydrazine do you think it is Better than SMB .

can you help me in that 
thanks


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## Anonymous (Nov 23, 2015)

Search denox on the forum and you'll find a whole host of answers - and welcome.

Jon


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## FrugalRefiner (Nov 23, 2015)

Why are you neutralizing aqua regia? Are you doing this before or after you drop the gold?

Hydrazine is highly toxic. I prefer SMB.

Dave


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## k_fassi (Nov 24, 2015)

they neutralize it before drop the gold 

i saw that in china and they was use Hydrazine to drop gold after neutralize.

i always use SMB for drop gold .


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## 4metals (Nov 24, 2015)

I see you're from Egypt (see it is good to post where you're from) We had a member who was taught by a group from, I believe, Egypt and he was doing it poorly. This thread will be very helpful to you. 
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=85&t=22243


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## k_fassi (Nov 24, 2015)

I share this photo with you to show you the result .
i wish hear your opinion


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## 4metals (Nov 24, 2015)

What material did you start with and how much material are you processing at a time?

The picture you posted shows metal in need of further processing. You can do better. Read the thread I posted the link for above.


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## k_fassi (Nov 24, 2015)

this photo is the gold he drooped from the AR


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## k_fassi (Nov 24, 2015)

4metals said:


> I see you're from Egypt (see it is good to post where you're from) We had a member who was taught by a group from, I believe, Egypt and he was doing it poorly. This thread will be very helpful to you.
> http://goldrefiningforum.com/phpBB3/viewtopic.php?f=85&t=22243



yes i'm from Egypt 

thank you and for all members for the information you wrote at your posts


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## k_fassi (Nov 25, 2015)

i have something like to know are i can use Ammonia solution to kill nitric or it is better to use sulfamic acid 

thanks for your support


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## FrugalRefiner (Nov 25, 2015)

Ammonia can cause difficulties in dropping PGMs and under certain circumstances it can create explosive compounds. Stick with sulfamic acid.

Dave


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## k_fassi (Nov 25, 2015)

FrugalRefiner said:


> Ammonia can cause difficulties in dropping PGMs and under certain circumstances it can create explosive compounds. Stick with sulfamic acid.
> 
> Dave




thanks so much Dave


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## k_fassi (Nov 25, 2015)

4metals said:


> What material did you start with and how much material are you processing at a time?
> 
> The picture you posted shows metal in need of further processing. You can do better. Read the thread I posted the link for above.



@ 4metals the material i use is E waste from PC and now i built a small business to recover gold from E waste then i write this topic to learn from you the best way i can recover gold and other Precious metals and not lose something . 
I'm sure you more experience than me and you will be helpful to me.

i read the the theard you sent and it was helpful for me.

about the photo i posted you said it need further processing. please can you explain to me what i can do 

thanks so much for your support


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## UncleBenBen (Nov 26, 2015)

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=85&t=22194

Here you go. Skip no steps. Do everything Harold recommends.


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## k_fassi (Nov 27, 2015)

UncleBenBen said:


> http://goldrefiningforum.com/phpBB3/viewtopic.php?f=85&t=22194
> 
> Here you go. Skip no steps. Do everything Harold recommends.


thanks


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## NobleMetalWorks (Nov 28, 2015)

Only make additions of Nitric Acid, so much as is needed. Preventing excess Nitric Acid is far better than neutralizing it after. You should only make small additions of Nitric, so that there is so little left over, you can drive it off with heat alone.

If you have a solution that has too much Nitric Acid left over from your initial reaction, you could always dissolve a known quantity of gold into solution, or you could drive it off using heat.

Scott


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## arisas (Nov 28, 2015)

The past few days after my AR solution dissolve all the gold foils i diluted with water equal 3 times more than the AR solution and after i add a few mls of Sodium Hydroxide there was no reaction (that happen to all of my AR solutions) and then i add SMB diluted with water and the drop of gold was a successes i test my solution after for gold with SC and it was negative . I think the water diluted the nitric acid and didn't need for Sodium Hydroxide.


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## FrugalRefiner (Nov 28, 2015)

I wouldn't add sodium hydroxide before reducing my gold. 

If your goal is to eliminate excess nitric acid, there are better ways to go about it. Add in increments to avoid adding too much, add a gold button to consume the excess, use sulfamic acid... 

Depending on what other metals are in solution with your gold, the sodium hydroxide could cause other metals to precipitate, contaminating your gold.

You also need your solution to be acidic to react with the SMB to create SO2. Bringing your solution too close to neutral could cause problems reducing your gold.

Dave


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## arisas (Nov 28, 2015)

FrugalRefiner said:


> I wouldn't add sodium hydroxide before reducing my gold.
> 
> If your goal is to eliminate excess nitric acid, there are better ways to go about it. Add in increments to avoid adding too much, add a gold button to consume the excess, use sulfamic acid...
> 
> ...


 You mean add a gold button before i filter it and after the reaction stops filter it and take back what remains of my gold button?, and if i test my AR solution after the drop with Stanous Chloride and its negative i am fine right..?


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## FrugalRefiner (Nov 28, 2015)

arisas said:


> You mean add a gold button before i filter it and after the reaction stops filter it and take back what remains of my gold button?, and if i test my AR solution after the drop with Stanous Chloride and its negative i am fine right..?


Correct. If you're interested in accountability, weigh the button before you add it, and again after you remove it.

Dave


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## g_axelsson (Nov 29, 2015)

arisas said:


> The past few days after my AR solution dissolve all the gold foils i diluted with water equal 3 times more than the AR solution and after i add a few mls of Sodium Hydroxide there was no reaction (that happen to all of my AR solutions) and then i add SMB diluted with water and the drop of gold was a successes i test my solution after for gold with SC and it was negative . I think the water diluted the nitric acid and didn't need for Sodium Hydroxide.


As Dave told you, using sodium hydroxide is not working really. If you get the pH too high you start precipitating various metal hydroxides, including gold I think. And it doesn't remove the nitrates from the solution. If you then acidify your solution again the nitrates will form nitric acid again and could dissolve gold.
What you want to do is to remove the nitrates as well as any nitric acid while keeping the solution acidic so metals doesn't fall out. Look up denoxing, it can be done in many ways. And it's all explained in Hokes as well time after time on the forum.

If you used sodium hydroxide some of the gold could have precipitated before you added SMB.
You should also filter the solution after you diluted it three times to get rid of any silver chloride that could have precipitated. Only solutions that are crystal clear should be used for precipitate gold unless you are only recovering gold and doesn't care about the purity.

Göran


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## butcher (Nov 29, 2015)

Using heat can be important when using the added gold button to remove the free nitric and any nitrates.


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