# how do you remove he base metals



## scrapit (Feb 12, 2010)

In some of the posts I have read people say to not forget to remove the base metals before using aqua regia. What does this mean, and how do you go about doing so. I thought you just made the AR and soaked stuff in it. Then neutralized it and filtered it then you had gold. Not to sound dumb but could someone enlighten me on this subject.


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## butcher (Feb 12, 2010)

base metals will contaminate your gold in aqua regia.
there are several problems you will be faced with by not heeding,
filtering can be very troublesome with some of the base metals, and when using aqua regia dissolving gold with base metals the gold will plate out onto remaining base metals, if solution is filtered the base metals will also collect your gold with them in the filter, eliminating the base metals is a little more work,but much easier than trying to get the gold from a dirty solution, and at the price of these metal and considering how rare they are, why throw out your gold with the wash water?

if using aqua regia nitric works well to eliminate the base metals unless it is from solder, 
if solder is involved tin makes a mess in nitric acid, or aqua regia, it makes filtering almost impossible and tin is also a collector of gold, tin can be removed with HCL.

there are many ways to eliminate the base metals, there are a few problems most all new people have, not eliminating base metals, not properly removing oxidizers, or using too much oxidizer or acids, using too much chemical or wrong chemicals, organics in solution, improper filtering or washing proceedures,and so on, this can be easy or hard, some may think dissolving base metals with thier gold is easier, in the end they will be looseing their gold, or working alot harder to keep or find it.


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## nickvc (Feb 12, 2010)

There are many different methods in refining but as a newbie i would follow Harold V,s posts as his instructions are clear and work if followed precisely.Harold always says read Hoke and he,s correct as it gives you clear easy ways to achieve success in virtually all materials.There are short cuts but until you have learnt the basics stick to methods that work everytime ,when you get a nightmare solution that just wont filter or is so contaminated that you have to do it all again you will wish you had stuck to the book,i know i did  its part of the learning curve but get it when you know how to correct it.


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## leavemealone (Feb 12, 2010)

Every hobby on earth has a history.You cannot just jump head first into a new hobby without having some sort of knowledge and information base for you to start with.In other words,if you were going to get involved into automobile racing,you would not go out and buy a transmission and then start asking "what do I do with it now?".Gold recovering and refining is no different.Here is the holy book on the subject http://goldrefiningforum.com/phpBB3/download/file.php?id=2480 .Start here.At the very least get a basic knowledge of the different methods for recovering and refining your gold.Then decide which path best suits your needs.Start small,do not dive in head first,and above all remember SAFETY!!! The 3 extra seconds it takes to don a faceshield may save your eyes,lungs,or even your life.I know you new guys are anxious(god knows I was same way years ago)but it took countless nights staying up with several friends and members on here before I started getting it right.I look back and realize,had I taken 2 days to read hokes book,she would have taught me everything from a basic platform to start from.......to "HOLY CRAP,DID I MAKE THAT BUTTON?"

OZ wrote:


> when I read a request for help,the more obvious it is by their post that they seem to have put some effort into educating themselves with all that is here on the forum,the more inclined I am to put forward an equal amount of effort in helping them.


So please take a few days and really research what it is you are getting into.
I hope I haven't offended anyone...that is not my intention.
Johnny


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## wifitekman (Feb 16, 2010)

Good Day All,

This is my first post/question. I have been reading posts for several months. I have a copy of Hoke's book and have been using AP on some foil fingers from various e scrap items. One item I have, is a PCB from the late 1960's. Copper wire was soldered to the gold traces. ( The PCB is from an analog counter) Being aware that base metals will complicate AP solution, I have been preparing to remove the solder before putting the PCB's in an AP solution. I have taken a couple of PCB's (1" X 2" ea.) and soaked only the portion of board with lead solder on it, in HCL. I gently warmed the board and HCL in a glass beaker until the solution started to "fizz". I removed from heat and let it stand for several hours - until the lead appeared to have disolved. I removed the baords from the beaker, rinsed and then put them in an AP bath. My question is this. What should I do with the disolved lead? I have not checked it with stannous yet, yet it appears that some of the gold trace may have disolved along with the lead. 
Some notes:
1. I have a good acid respirator
2. I wear proper eye protection as well as chemical gloves.
3. I Work either outdoors or in a job shack where all metal and electronic equipment has been removed. 
4. When working in my job shack, I open the doors and windows. 
5. Safety and good health -

I have purchased a copy of Steve's video processing PC cards, a melting dish and mini oven. Haven't used the oven yet. I also hope to sell some recovered gold someday, too. But I have donated to the website ahead of sales. Recovering gold is a lot of work. Putting together a website and forum is a lot of work too. If it is advised that I read more, than so be it. If not, thanks in advance for the help and continued advice. 

Audey
wifitekman
Lynden, WA.


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## butcher (Feb 16, 2010)

Lead chloride is insoluble in cold water.
Lead would tend to be insoluble in cold acid peroxide,
if gold did dissolve in acid peroxide (high oxidizer too much peroxide)it would precipitate back out when more copper added and oxidizer was overcome, could fall to bottom as brown powder or plate to metal copper still in solution.

Lead chloride is slightly soluble in hot water. silver and gold insoluble, although a boiling solution may be agitated and these powders can take time to settle, if small amounts of lead in powders boiling hot water can be used to dissolve lead chloride.

After collecting a batch of lead powder.
Here is one way I deal with lead powders, after collecting a batch,
HCl/bleach to cover powders and slight excess stir well, some times I use heat, let sit day or so, decant solution may contain gold, dilute and settle filter solution, test for gold and treat solution with precipitant if it does. Depending on gold content may need more than one treatment
Add three times volume of water or more to lead powders, bring solution to boil, lower heat to just below boil, keeping solution hot, letting silver and extra lead settle,(silver chloride is insoluble in hot water, the silver powder will take time to settle), (lead becomes more soluble in boiling hot water, although not all will dissolve only as much as hot water will hold), while this lead water is hot decant liquid to a cooling jar, where the liquid will cool and the more pure lead will precipitate, I raise heat to low boil on pot, after water in cooling jar has cooled and precipitated its lead, I return to boiling mixture and repeat this process, till all lead removed as possible, this lead powder, I rinse and save for use in other processes( lead is a collector in a melt). Can calcine lead at 600 deg C in air to make litharge for mixing with flux.

If you have a small amount of lead and mostly gold it can be cupuled to give gold button, but a lot of lead would take up a lot of cupules
Lead is toxic take precautions.
hope this answers your question, as I am not exactly sure what you meant by how do I deal with lead.


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## wifitekman (Feb 18, 2010)

Thanks for the reply butcher. I have spent the last day trying to figure out a better way to post my question. I'll try another way, less wordy. 
I put a PCB that has solder on it in HCL. The solder has disolved and has settled to the bottom of the beaker. What should I do with the settled material?


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## butcher (Feb 18, 2010)

I put it in a jar and save till jar full then try and get any values it may contain, I save my lead for other uses. 

an idea- one way to safely dispose of dried lead powder, put in old lead acid battery for recycle. or hazardous waste amnisty day.


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## wifitekman (Feb 19, 2010)

butcher,

Perfect! and Thank you.


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## g_axelsson (Jul 15, 2010)

Digging up an old topic here...



wifitekman said:


> I have not checked it with stannous yet, yet it appears that some of the gold trace may have disolved along with the lead.



Melted tin-led will dissolve the gold. The gold in it self becomes a part of the solder joint. When the solder is dissolved in HCl it will release the gold as a fine powder, probably suspended in the solid lead chloride or as a colloidal solution.

Unless you have a lot of it I don't think it is worth the hassle to recover the gold.

/Göran


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