aqua regia mistake

[solar seeker]

OK this is my story I made aqua regia using the sodium nitrate/meuratic acid method and proceeded to dissolve about a pound of gold plated pins fingers and chips while capturing the fumes in several 1 gallon glass jars and reacting that with water to reclaim the valuable nitric acid. After the metal was dissolved I filtered the solution and boiled it to remove the remaining traces of nitric acid ,which was paltry when compared to the fumes from the original mixture. After I was done boiling the aqua regia and removed it from the heat it continued to react with itself causing it to boil over briefly. After that I had found out that I bought sodium bisulfATE instead of sodium bisulfITE which was a double let down because I had originally intended to buy sodium metabisulfate in order to make sulphuric acid with. I spent a short time trying to find some evidence that this product would work and found that the chemical I had has one more oxygen than the sulfite variety. So in spite of various websites stating that it wouldn't work I decided to try it any way. Since it didn't do anything except fizz briefly I figured I had ruined my mixture so I added some pieces of aluminium to the mix in order to precipitate out all metals in the solution. The solution is outside and likely quite warm and still fizzing as I type this. :|

Any help would be quite appreciated

 

[Barren Realms 007]

Oh what a tangled web we weave. Is this a new TN home brew still?

HMM let's see what we have here.

Copper, iron, tin, possibly some silver, gold?? You have a real mix on your hands. Everything a growing young man needs. And let's not forget the aluminum!

Anything else you might have forgotten to mention that might be in your mix?

Do you have any stannous to test your solution?

How much solution did you start with? How much do you have now?

How much material if any of the original lb is left in the bottom of the bucket?

I would possibly neutralize with urea and then drop everything out of solution and start again with less solution.

Get a copy of Hokes book here in links and do some reading. Do some searches here on the forum on what you are doing and do a lot of reading.

Good luck.

 

[solar seeker]

The aluminium neutralized the hydrochloric acid pretty well but it didn't drop everything out of the solution.
I would say that up no more than 1/4 of the weight of the original material was metal the rest being plastic and fiber glass board. Now that you mention it I mixed the aqua regia with some spent PCB etchant solution which claims to be ferric chloride and hydrochloric acid so other than extra iron and perhaps copper there shouldn't be anything that affects the chemistry. Also you missed lead and perhaps bismuth from the solder. Unfortunately I don't have any stannous chloride to test the solution with. Surely there has to be a way to synthesise it or find an alternative solution. The current amount of solution I have currently is little over 1 litter or 1 quart depending on your nationality. I would like to note that because of my chemistry hobby I'm using glassware to handle the chemicals in whenever possible which is why I'm able to reclaim the nitric oxide fumes though I'm going to need to seriously upgrade in size in order to do more than 500ml batches

So since aluminium hasn't dropped everything out of the solution would adding more hydrochloric acid to continue the reaction do or is there something else that would work better ? I would like to think that I could simply boil down the solution until all I have is metal and metal oxides. After that I could smelt it all together then save it until future batches yield enough to be worth trying to refine it again. The problem is I don't know if it would work well enough to be worth trying.

Btw thank you for your help but from what you're telling me it looks like I have a long way to go before my first pay day.
Until then I'm doing all of this at my own expense and because of that the number of chemicals and equipment I can buy is extremely limited.

 

[nickvc]

Barren was been helpful and the last part of your post indicates that your funds are limited so do what he suggests. Stop and read Hoke until you understand what your doing, this is available free as a download,this will save you money time and hours of frustration. The members here all understand the desire to rush ahead, most of us have done it at one time or another, but the best way to be successful in refining is to be prepared and to know what is occurring in your reactions with acids and the object of your desire GOLD. Spend your time learning and read as many posts as you can,use the search function to further your knowledge,you haven't lost your gold it's still there but it's going to take you a while to understand how to recover it and this might be the best lesson you ever have.

 

[qst42know]

Don't add anymore acids.

I don't think adding urea is necessary after adding a surplus of aluminum any values cemented should have consumed any nitric acid remaining.

Aluminum won't stop things from floating but it will make things difficult to filter. Anything of value should be solids at this point. Time to filter.

 

[Anonymous]

Unfortunately I don't have any stannous chloride to test the solution with. Surely there has to be a way to synthesise it or find an alternative solution.

If you cannot find tin solder,then heat up one of your boards that has a good amount of solder on it(needs to be a newer board,not a vintage board) until the solder turns to liquid and hit it on a large cookie sheet(don't use a good one obviously).Use that solder to make a solution,and test it on some positive auric chloride to make sure it worked.
For the stannous,add about a gram or 2 of tin to 10-20ml of muratic.
For AuCl take some pure gold flakes and add them to a little muratic with just a splash of bleach that contains at least 3% sodium hypochlorite.

 

[solar seeker]

If I know my chemistry right, mixing muriatic acid and bleach will release chlorine gas which is rather unfriendly to the lungs.
Also who is this Hoke person everyone's referring to because a Google search turns up nothing useful? By the way if muriatic acid and bleach will dissolve gold
then why does everyone use aqua regia when this is so much cheaper :?: In addition to this if I had pure gold I wouldn't be failing to refine it off of computer parts in the first place. I do have a few more pins and gold plated boards that might work if I use them. Oh and thanks for the information on stannous chloride, that will help tremendously .

 

[Barren Realms 007]

If I know my chemistry right, mixing muriatic acid and bleach will release chlorine gas which is rather unfriendly to the lungs.
Also who is this Hoke person everyone's referring to because a Google search turns up nothing useful? By the way if muriatic acid and bleach will dissolve gold
then why does everyone use aqua regia when this is so much cheaper :?: In addition to this if I had pure gold I wouldn't be failing to refine it off of computer parts in the first place. I do have a few more pins and gold plated boards that might work if I use them. Oh and thanks for the information on stannous chloride, that will help tremendously .

Yes it does create chlorine gas(that is what dissolves the gold). It is very unfriendly to the lungs and every other part of the body. That is why it is suggested to use a fume hood or work outside.

Hoke is a lady, you possibly will not find anything on the internet about her. Only thing more precious here on the forum than her book is god's word(woop's sorry I can't say that).

HCL/clorox is recomended over AR here on the forum till you learn what you are doing and what reactions take place during your processes. Most of the time it is easier to recover your values from HCL/clorox than it will be from AR. It is also a more forgiving solution to work with when you use excess amounts of solution, as most new people do when they start out learning the processes.

This can be easy to learn if you read a lot here on the forum and start off with small batches to process. Do searches on what you are trying to process and the chemicals you are using, read the MSDS sheets.

Develope a lot of humbilness you will need it when you rush things and make mistakes. And just about the time you figure you have things under control, bang something will come up and bite you in the A** and you be asking for help. You show you are trying and you will get all the help in the world here from the best group of people you will ever run across or deal with. None of the leaders here will stear you wrong or let you be led down the wrong path that will put you in danger.

 

[gorfman6154]

OK this is my story I made aqua regia using the sodium nitrate/meuratic acid method and proceeded to dissolve about a pound of gold plated pins fingers and chips

Any help would be quite appreciated

Solar seeker, don't get caught up in all the hype on the internet. If your going to proceed with e-scrap, it would be wise to start by sorting your different types of material, cpu's, fingers, and pins. Each type of feed stock has there own optimal way to process it. If you combine all your scraps in one batch, you will be starting many more threads, asking for help. If you do some research and reading of this great forum, you will find many ways to process all your different types of scrap. There is the crock pot method, Acid Peroxide, HCL/CL, reverse plating cells, to name a few, which are made using readily available and inexpensive ingredients.

Read Hokes book to learn the basics, then read the Forum for all of the unique work arounds.

It would be wise to learn the difference between recovery and refining, which use different methods to achieve different ends. But in the end, you come out with some really pure Gold buttons.

There are great teachers on this Forum, read the posts, and they will be happy to help.

Good luck with your education.

Gary

 

[Harold_V]

Damn, I'm proud of you guys. I hardly ever have to say anything anymore---the older and more active readers have picked up on all the fine points and are leading the newbies down the right path. I congratulate each and every one of you.

Harold

 

[gorfman6154]

Damn, I'm proud of you guys. I hardly ever have to say anything anymore---the older and more active readers have picked up on all the fine points and are leading the newbies down the right path. I congratulate each and every one of you.

Harold

Harold, thanks for the high praise, but for everyone who has refined even a single gram of gold, they should be extremely grateful for fellow members like yourself. I'm not going to start listing names, because someone would be omitted.

You freely give of your time to teach and mentor people in a field (refining) which is filled with all kinds of people who are just in it for a quick buck.

You, the moderators, and all active members, who dispense advice, are the greatest teachers. You might not have to say it, but via a proxy member, it's still your knowledge at work.

It not said often enough, thanks to everyone for your time and effort in teaching new skills to anyone who has the desire to learn them.

Gary

 

[chemist]

If I know my chemistry right, mixing muriatic acid and bleach will release chlorine gas which is rather unfriendly to the lungs.
Also who is this Hoke person everyone's referring to because a Google search turns up nothing useful? By the way if muriatic acid and bleach will dissolve gold
then why does everyone use aqua regia when this is so much cheaper :?: In addition to this if I had pure gold I wouldn't be failing to refine it off of computer parts in the first place. I do have a few more pins and gold plated boards that might work if I use them. Oh and thanks for the information on stannous chloride, that will help tremendously .

Here is a link to a free copy of the book by C.M. Hoke that everyone keeps mentioning.

http://www.scribd.com/doc/2815953/Refining-Precious-Metal-Wastes-C1-M-Hoke

The process that you use will depend upon your starting materials. AR will dissolve almost all metals (watch out for those with a high silver content), but it produces a lot of poisonous red nitrogen oxides and (this is key) you must eliminate the nitric acid from the AR before you can precipitate gold. It is much easier to eliminate the chlorine from HCl/Cl before precipitation.

 

[lazersteve]

Excellent replies all the way around I must agree.

I would only add that Solar seeker should read the Guided Tour links to get acquainted with the basic reactions and vocabulary. I can always tell when a new member does not read the Guided Tour by their questions. The other members and myself have spent many hours writing the information that the Guided Tour can bring to their finger tips if they would only click on that one link in my signature line below.

Steve

 

[solar seeker]

I can't believe how friendly the people here are. This must be THE most friendly forum on the Internet because every reply gets straight to the point and is
nearly always helpful. Btw thanks for the links for the book and the guided tour. I had intended to read the guided tour but it wouldn't let me read it without signing up then after I signed up I couldn't recall where to find the link to it.

 

[butcher]

thank the moderators for keeping the bad apples outa the barrel.

 

[nickvc]

thank the moderators for keeping the bad apples outa the barrel.

I,ll second that very happily.

 

[chemist]

I can't believe how friendly the people here are. This must be THE most friendly forum on the Internet because every reply gets straight to the point and is
nearly always helpful. Btw thanks for the links for the book and the guided tour. I had intended to read the guided tour but it wouldn't let me read it without signing up then after I signed up I couldn't recall where to find the link to it.

Just wait until you get our bill !!
You did input your credit card information when you joined the forum. Right?
:lol:

 

[solar seeker]

Update: I checked the solution which is now a clear Grey and has about 50ml of copper crystals mixed with aluminum and perhaps other metals.
After I removed the copper crystals the aluminum chunks continued to react with the solution so I put them back in with a little steel wool which has precipitated the last of the copper and is now beginning to precipitate a black sludge with silver specks in it which I will keep until I find out what it is. I've been reading on this forum all day because it is a gold mine of information (pun intended). My first batch of stannous chloride either doesn't have tin in the lead free solder's make up or as I've read there could be nitrates messing up the results (though it seems unlikely).

 

[Barren Realms 007]

Update: I checked the solution which is now a clear Grey and has about 50ml of copper crystals mixed with aluminum and perhaps other metals.
After I removed the copper crystals the aluminum chunks continued to react with the solution so I put them back in with a little steel wool which has precipitated the last of the copper and is now beginning to precipitate a black sludge with silver specks in it which I will keep until I find out what it is. I've been reading on this forum all day because it is a gold mine of information (pun intended). My first batch of stannous chloride either doesn't have tin in the lead free solder's make up or as I've read there could be nitrates messing up the results (though it seems unlikely).

How much solution are you trying to make at one time, and how much lead free are you using in it?

Possibly about 10ml is all you need to make at first.

Did you heat your solution?

Don't think you will have a problem with nitrates with just HCL an lead free solder.

 

[qst42know]

Update: I checked the solution which is now a clear Grey and has about 50ml of copper crystals mixed with aluminum and perhaps other metals.
After I removed the copper crystals the aluminum chunks continued to react with the solution so I put them back in with a little steel wool which has precipitated the last of the copper and is now beginning to precipitate a black sludge with silver specks in it which I will keep until I find out what it is. I've been reading on this forum all day because it is a gold mine of information (pun intended). My first batch of stannous chloride either doesn't have tin in the lead free solder's make up or as I've read there could be nitrates messing up the results (though it seems unlikely).

You are making this a bigger mess than you need to.

You don't need to completely neutralize your solution with base metals for your PM's to be down. The solution can remain acidic well after all your values are down. Base metals replace precious metals in the solution any excess is more waste.

Adding steel wool after aluminum is a waste of time. Aluminum is higher in the electromotive series and will drop even the iron from solution.

:!: Please no more additions. :!: You are only making yourself more crap that needs removed to get your values back.