First Refining

Shop deals on ebay
shop deals on amazon
xelexo
Advertise with us
Gold Refining Forum

Help Support Gold Refining Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
S

Saminator

Active member
Supporting Member
Joined
Nov 18, 2008
Messages
26
Location
Lake City, FL
Well I have finally started my first batch. It is a small test...150g of very poorly plated pins. First, I dissolved my pins in 550ml of Nitric Acid (70%). Which did not yield what I was expecting. I was expecting a nice blue colored solution with a nice pile of golden flakes in the bottom of my beaker. What I got was, a pale blue solution, lots of white to light gray powder and the expected golden foils. The white/gray powder made filtering nearly impossible. I washed the powder 3 times with Distilled Water. I took my gray powder and gold foils and added 300ml of HCl and 25-50ml of Clorox...my foils dissolved promptly and I began the process of filtering again. Now I am left with a solution, which very much resembles everyone else’s pics of auric chloride. Stannous Chloride test show the solution is indeed pregnant with gold. I heated my solution to nearly boiling but not quite boiling for 30 minutes evaporating 50ml of the solution (in an attempt to drive off the excess Cl in solution). I added about 30g of SMB...nothing, added another 30g of SMB still nothing...did this 5 times. I still have no precipitation and still tests positive for gold with Stannous.

Can anyone help identify this white/grey powder that hates to be filtered?

Can anyone suggest what might be holding my gold in solution and what steps I might take to liberate it?

TIA for all you help!

Sam
 
(1)IT is silver nitrate and nickle nitrate because pins is consist of nickle copper silver and gold . (2)Check your precipitant is it sodium metabi sulfide or not I think you use sodium metabi sulfate.use another precipitant ferrous sulfate(copperas).
 
Welcome to the Forum,

I question how much gold can be expected from 5 oz of plated pins.

I personally would reccomend LazerSteves site, that shows you how to use a electrolytic cell to strip these pins' gold from the base metals. I don't like the nitric for materials that contain silver, "In Pins?", nickel, or tin.

There is another topic on this forum, for haveing trouble with dropping gold from Auric Chloride solutions. I cant find the thread right now. I will try to repost, but re-check as stated to your SMB, it should be Sodium Meta-bisulphite. not IDE or ATE

If you really get worried, you could look into cementation with just copper, or steel to drop everything in solution, and start over with fresh chemicals, but I think you'll figure it out here quickly.

Best of Luck,
Nick
 
Having similar problem with high-to-mid grade pins. Have run thru 1 batch of HCL+peroxide - pulled a small amount off but think Steve's electro method my be my best bet to get all the gold off? Correct?
Since i'm a newbie, just checking my thinking?
Steve, Harold and to all the other experts - wish you'd been available when i had my recyc biz...got burned by the big refiners in 2000
knowledge here "is" gold
The peroxide treatment is working great on my pcb's, lots and lots of flakes!
THANK YOU ALL :D
 
kbostwick said:
Having similar problem with high-to-mid grade pins. Have run thru 1 batch of HCL+peroxide - pulled a small amount off but think Steve's electro method my be my best bet to get all the gold off? Correct?
:D
Click to expand...

I would say yes. Then do you acid washes and you gold is pretty pure at that point.But do a final . The acid peroxide is really geared at the thin coatings that hold the foils on fingers, Though it can be used for pins the added cross section and size of the pins is greater than that of the surface that holds things like finger foils. So the amount of material going into solution is greater which means you use more acid's and the time to dissolve the pins is greater.

With the cell you are just deplating the pins and leaving the base metals to which it is attached in tact. Though some other metals will slightly dissolve into the mixture these will be removed when you do your acid wash in the next step leaving you with fairly pure gold.
 
Great Posts aflacglobal,

I appreciate these as much as the next.
do you have a lot of youtube videos as well? Seems I have viewed a lot of refining related videos on youtube with AflacGlobal as the sender as well?

Nick
 
First, thanks to everyone who has responded it really has me thinking out of the box.

aurumshin said:
(1)IT is silver nitrate and nickle nitrate because pins is consist of nickle copper silver and gold . (2)Check your precipitant is it sodium metabi sulfide or not I think you use sodium metabi sulfate.use another precipitant ferrous sulfate(copperas).
Click to expand...

I think it is unlikely my white/gray powder is Silver Nitrate, if Silver were present I think it would stay in the Nitric solution as it does when enquarting or refining 925 Silver. Also, I tested my filtered nitric solution with table salt and got no cottage cheese precipitation.

Yes my SMB is the right SMB. I purchased it from a Home Brewing vendor suggested by LazerSteve.

I will come back to the Nickel Nitrate idea in a bit.

nicknitro said:
I question how much gold can be expected from 5 oz of plated pins.

I personally would reccomend LazerSteves site, that shows you how to use a electrolytic cell to strip these pins' gold from the base metals. I don't like the nitric for materials that contain silver, "In Pins?", nickel, or tin.
Click to expand...

This is my first refining and is a mere test. I do not expect to get much from 150g of plated pins.

I have been to Steve’s site, seen all his videos, in fact I purchased them from him on DVD. Let me tell ya why I am not going Electrolytic Cell. These pins were all soldered onto a board at one point in time. They all are still 30-40 % covered in solder. I suspect the cell will not etch under the solder and consequently I would loose 30-40 % of my values. I am having a hard time seeing the difference between plated pins and gold filled items.

Now, back to the Nickel Nitrate. I think that deserves more thought. The pins were magnetic so I do suspect Nickel or Iron (what does Iron Nitrate look like?) Would Nickel Nitrate work to make a weak filthy poormans AR in my HCl/Cl solution? Could this flavor of poormans AR be what’s holding my gold in solution? Will evaporation or urea clear out the Nitrate and let my gold come down?

Your thoughts are all appreciated!

Thanks,
Sam
 
(1)copper is used to precipitate silver in nitric acid , pins is consist of silver and gold plating under is copper , first nitric acid is dissolve silver plating when silver plating is remove then copper dissolve in nitric acid, this copper precipitate your silver as gray poweder on the bottom .i wrote wrong in first time that is silver nitrate it is silver.(2)if you inquire that nitrate is present in your solution put grain of urea in your solution if you see bubbles it means nitrate in your hcl-cl . if you see bubbles try this make urea solution with water filter it and add drop by drop when whole nitrate is gone then use your smb .(3)if you not see bubbles change your precipitant copperas because many situation smb not work good.
 
Saminator said:
The white/gray powder made filtering nearly impossible.

These pins were all soldered onto a board at one point in time. They all are still 30-40 % covered in solder.
Click to expand...
Bingo!

Now you know why you have a problem. And----incineration is your friend.

If you intend to process solder, you will have these problems. One thing you can do to improve the material's ability to process is incinerate the recovered white stuff, along with the traces of gold. Heat it until it is near a dull red heat, but do not melt anything. Stir it well, so all of the material is exposed to air. After the material has cooled, crush with a mortar and pestle, and screen, so all of the material is reduced to powder. Next, boil the lot in HCl. Discard the solution, rinse well (tap water is acceptable) then process the remaining solids for values. The gold may not come down perfectly clean, but you will have processed all of the gold. A second refining would assure quality.

Harold
 
Thanks aflacglobal
I let the pins sit overnight w/ a few stirs and more came off but the electro method is the way to go!
Thanks again!
 
Well, first I should thank everyone again you guys are the greatest! Next, let me say I got my gold out of solution!

Harold, I was just thinking before reading your post, "I bet Harold would say incinerate" and sure enough there you are. :p My new friend Incineration is moving in tomorrow, I just hope it doesn't eat all the food in the fridge and leave big messes in the Restroom...

How did I get my gold out you ask? Well I basically did nothing. I think my problem was concentration. I waited a couple day as I was thinking what I would do next and waiting for everyone's advice when I noticed a very very very fine layer of a brownish red powder in the bottom of the beaker and my solution tested negative for PM's. Remember I only started with 150g of lightly plated pins, I boiled it over twice with the Nitric and again with the SMB (add your chemicals SLOWLY, do NOT fill the beaker full and put your beaker in something to catch spills). I am sure I lost most of my values with these boil overs. So, I think my first SMB addition was enough to get my gold down, but it was so miniscule I just couldn't see it in the solution. So, I am calling this experiment a success.

FYI Since then I processed (w/ AP) 1300g of fingers and it worked without a single hitch. I also equarted 4g of 14K and that also went well. I have about 60 P2's that are next. I will post some pics of my buttons soon in the gallery.

Thanks so much to everyone for their help!

Sam
 
Is there a way to process these pins that are covered in solder, without getting the white powder problems in the first place?

I've got 10Kg of them and been leaving them alone as they look like trouble to me! :evil:

Regards
Buzz
 
They can be trouble.

Harold gave the proper advice but may have left out some details as to the why of what he recommended (put me in my place if I am wrong Harold). It is important to remove tin that is found in most solders or other electronic components such as CPUs in HCl with heat first. The added bonus is the removal of much iron, and copper as well that will do wonders in later precipitation. Tin will beat you senseless once it encounters nitric with the only solution being to incinerate to remove nitric and start over with HCl.

You will still have some silver chloride and lead sulfate (white powder) problems to deal with if you use proper dilution of your auric chloride and the addition of sulfuric, but these filter or decant well.
 

Latest posts

Back
Top