# How long can gold stay in AR



## avrgeg46 (Feb 7, 2012)

hey fellas. just wanted to know how long i can leave my gold in the aqua regia? does the acid start getting weak so the ph will go up? I added urea with no results. Thanks for you time


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## jimdoc (Feb 7, 2012)

avrgeg46 said:


> hey fellas. just wanted to know how long i can leave my gold in the aqua regia? does the acid start getting weak so the ph will go up? I added urea with no results. Thanks for you time



Why would you ask that in a topic labeled; "Silver plated scrap for silver recovery"?


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## avrgeg46 (Feb 7, 2012)

if you read my welcome post you would know why. it took me a while just to figure out how to post let alone post it in the right topic area


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## jimdoc (Feb 7, 2012)

avrgeg46 said:


> if you read my welcome post you would know why. it took me a while just to figure out how to post let alone post it in the right topic area



Hey, I am not picking on you. I am just pointing out why you may not get your question answered.
Maybe a moderator can move the question to an appropriate location.
You don't need urea, but what results were you looking for by adding it?

Jim


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## lazersteve (Feb 7, 2012)

I split the topic to a new thread for you.

Welcome to the forum.

I've leave my pregnant gold solutions layng around for months sometimes. If they dry out simply add water and preciptate when you are ready.

No need for urea, simply denox or use the right amount of nitric to begin with.

Check out the Guided Tour for general forum skills and chemical information.

Steve


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## avrgeg46 (Feb 7, 2012)

thanks for moving my post steve. very much appreciated. i am trying not to bug anyone and i have been reading lots of different posts. so many that, i think my brain is going to pop! information overload. I don't know if any of you have read my welcome post, but to put it in a sentence, i am trying to figure out how to refine (what seems to me like) everything you can think of. I really dont have a clue as to what metals are in all the different things we have so i decided to just start with some gold plated pins. we have a few bucket fulls of them and it seemed like the easiest thing to start. they aren't like the little computer pins either. they are about1/8 inch diameter and about 1 1/2 long and i am pretty sure that under the plating is some type of alum. alloy. then the crimp on them has a small piece of insulated copper wire smashed on it. So what i have gathered so far from all my reading, and i will confess that I have been on the shor site and read a bunch of the stuff they have on their site. But i have been learning that just about every site that i have been on is pretty shady about giving you all the info that is needed to complete a process. OK, I also confess that i did buy some of the chemicals that they have too. [email protected]#$%^t! Oh well, I suppose that is all part of the learning curve. Can't do everything right the first time. Can I? No, l can't soooo, I took the pins and soaked them in nitric for about 30 minutes. You are probably wondering what strength of nitric? Well i was wondering that myself. See the nitric we have doesn't say anything on it so i am lying if i tell you 70%. Reacts like 100% though on the pins. I'm sure that has to do with the aluminum though. So after 30 minutes i add hcl (actually its pool acid and only 15%. Say's it on the lable. Probably not storng enough though cause all the stuff i been reading mostly say's 36%. I wait for about an hour after the brown fumes stop. I add urea to bring ph to 1 <>.02. Dont ask me how i test the ph cause i haven't. I just know that i need to bring it to 1 and not 1.5. why i am not sure but i remember reading it. Then the home depot (bonide) stump out. (got that of this site) to drop the gold. so far I haven't made it to that point yet. I have about 1500 ml of ar that i have been taking little amounts at a time and trying to get it right before i do the whole thing. The math on the chems evades me sometimes though. pretty small amounts. So this is what i am doing as my friend is over in the other lab trying to pull the silver out of some (I am at a loss for words on this one) I guess it's kind of ore but not. mostly crushed crucibules and some classified ore from his dad's mine. That's a whole other story though. So that's where i'm at and don't be shy telling me im retarded cause right now it's a starting point and eventually i will get the jist of it all. so back to reading and getting lost. I always start out looking for something specific but a couple hours go by and i am totally off on some completly different subject before i relise what I am doing. So much good info though. Thanks for your time and if i am wasting it please help someone that is at a point where the info will help them I will eventually get it, and you will see me on the forum so thanks again and be safe!!!!


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## jimdoc (Feb 7, 2012)

You probably should have looked into using the sulfuric cell on those pins. 

You ended up with aqua regia with your mixture, so you probably have gold in solution or cemented on your pins. I hope you are doing this outside or a safe place for the fumes.

Also, try to space out your writings into smaller paragraphs. It is very hard to follow what your saying in one giant paragraph, at least for me.

Jim


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## Geo (Feb 7, 2012)

here's a couple of things. nitric acid does not like to react to aluminum, it will passivate (the very outer layer will oxidize preventing further attack). if the "pins" reacted strongly they may have been brass with gold plating. by the way, do you have pictures of these pin? from the description you gave, it sounds like RF connectors. this can be both good and bad depending on the source, good as in gold is where you find it and bad as in newer RF connectors are just flash plated and have very little gold on them. when you put the nitric in and before you added the hcl, did you see any gold foils floating around in this mess? if you did then you have the good type but if you didn't it doesn't mean you have trash but it may be you spent more on chemicals than you will retrieve in gold.


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## butcher (Feb 8, 2012)

avrgeg46,

Welcome, I find your question a bit wordy, information on what your asking is needed, but filtering through what happened last Sunday it begins to confuse me on what you are asking.

It sounds like your nitric may have been 70%, we usually dilute it, and less chance of foam-over and the nitric acid will actually work better.

After you treated the pins in nitric acid you should have decanted the solutions from the solids, checked the solids to see if you have dissolved all of the base metals, and if there was silver or palladium involve retrieve this from the nitrate solution, (from your description this does not sound like you would have these).

If pins were copper or brass type material the copper would color solution blue to green color as nitrate salts dissolve in solution (copper nitrate).

Washing the powders and stirring these you can tell if all the metals like copper dissolved, if not (heavy pins), then you may need more nitric to finish dissolving the copper.

It is a good Idea to weigh your scrap (incinerate the oils, plastic, and trash off of it), then calculate about how much nitric you need, and work form there.


By adding Hydrochloric acid (HCl) to this copper nitrate solution (with your un-dissolved gold), you would have dissolved everything the acid could into aqua regia. As Jimdoc said.

If you have no metal left and everything is dissolved together, if you did not incinerate the pins to begin with, and if they had any solder, then added urea (good for lawns, but not for removing nitric acid from aqua regia in my opinion),this all adds up to you have one big mess on your hands, and your gold locked up in this mess.

If this is the case use copper to cement values, save the powders, neutralize them with sodium hydroxide pH 7,rinse out the salt water and dry powders, store them in safe place mark the container, big mistake possibly gold.

The solution separate from powders, go to the safety section read dealing with wastes to treat your acidic toxic metal waste solution according to instructions.

Read Hoke's book more, practice the experiments, and read more on the forum.

you are like most all of us when we begin to learn we get excited to try things out and get some gold, before we completely understand what we need to learn yet this is the new mans mistake almost all of us make (it is also where most of us have lost gold).

by doing Hoke's getting acquainted experiments as you read the book you will get the lab work you crave, an understanding of how and what happens and why.

I also feel that beginners should start with memory fingers (acid peroxide) Copper II chloride etching solution to dissolve the copper from foils, then use the HCl/Bleach method to dissolve the gold, eliminate excess chlorine from solution then precipitate the gold with our reagent of choice, washing it using Harold's instructions (getting gold pure shining post in General Chat, {I think}), then melting a pretty gold button, this is a much easier process and doing these first you will learn much before doing many of the harder processes.

OK your right, sorry my post is also wordy, but I hope it helps you get on a more productive trail.


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## niteliteone (Feb 8, 2012)

butcher said:


> avrgeg46,
> (snip)
> OK your right, sorry my post is also wordy,



But understandable :shock: 

I stopped reading half way through the OP's post because I lost track of where it was going.

Sorry
Tom C.


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## avrgeg46 (Feb 8, 2012)

sorry guys for the long post.

1.didn't incinerate pins.

2. 300 grams of pins (approx. 1 gram per pin before oxidation.)

3.(Outside of the lab) 300ml nitric for 30 min. 4. 1200 ml af 15% hcl overnight.actually, 2nights cause i wasn't sure of the next step and I had to get the materials. total liqiud 1500ml+pins.

4. took out about1/4 fl. oz of solution and added a few drops of urea (wet) to solution in test tube. No reaction or fizzing. a few more dropsand still nothing.

5. Added more nitric to the 1500ml of solution and put on hot plate for a while. figured i had the ph to high maybe so this is the only way i figured i could bring it back down. about 100 ml less solution now evaporated off.

6 The solution is a clear dark green but when in a smaller container it lightens up quit a bit. light green. In step 3 above, after adding nitric the gold was floating everywhere. looked like one of those christmas things you shake and it looks like it's snowing. 

7. I have re-filtered it a couple of time and i have good filters and buch funnel so i know there is no solids in it. 

that's where it sits. if i do anything i always take a sample and do whatever it is i am doing to that. not the main solution. I will have to get some photos of all the stuff we have going on and equipment so you kind of have an idea of what i'm working with. 

Hope this is a better format for readability. Again sorry for all the jibberish. I told you my brain was on overload. LOL.....

I really do appreciate all of your advice and promise to be diligent at adhere to all saftey issues and personal protective equipment. The forum is wonderful and everyone is blessed to have people around that care about others they don't even know. Great characteristics and values. Hats off to Noxx and the rest of the team. Great job!!!!


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## butcher (Feb 8, 2012)

Separate the gold foils, add a large piece of copper to solution it will cement the gold as a black powder, brush off copper bar rinse and dry store in plastic bag for this purpose.

The solution after gold is cemented using copper can be tested with stannous chloride.

Iron added to your copper chloride solution will cement copper, then raising the pH to 9 will let most of other metals precipitate, then bring ph to 7 and this iron salt water solution will be safe to dispose of, you can read more about this on a post 4 Metals done in safety section dealing with waste.

I will let you get back to Hoke's book.


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