New beginner member

[Rick Baker]

Hello everyone My name is Rick and I live in Minnesota. I have been scrapping e-waste for quite awhile, selling my PC boards to a company here. I just started trying to recover gold from them 2 months ago with not much success. I did get .5 grams gold powder from a small batch of gold fingers I had, but when I tried doing it with some gold plated pins, I have failed. I am left with a black liquid I think has a lot of base metals with the gold. I tried to dissolve the pins in DI water, sulfuric acid and sodium nitrate prills to dissolve the base metals. It was working, but taking long. Most of the base metals were dissolving and I could see a lot of golds flakes. I would filter off the solution to collect the gold flakes on a filter. Then put the solution back on the pins with another 1/2 spoonful of the sodium nitrate prills. Eventually I thought the metal that was still left in the beaker would not dissolve. So I added the filters I hade with the flakes into the beaker with mostly dissolved pins and did AR. The AR never got golden colored, just black. I filtered it thinking that would help, but did not. So I thought this is dirty solution and I could just precipitate the gold out of it. I tested with status chloride, but the solution was dark already and could not tell the results. So I just added SMB to it and waited till the next morning. I seen something on the bottom and thought it might be the gold. I was wrong. It is some kind of crystals. maybe the SMB here is what it looks like now. I hope some one can tell me what I did wrong and if I can fix this. I down loaded C.M. Hoke's book from here and just stated reading. Thank you to all who made that possible.

 

[Yggdrasil]

Hello everyone My name is Rick and I live in Minnesota. I have been scrapping e-waste for quite awhile, selling my PC boards to a company here. I just started trying to recover gold from them 2 months ago with not much success. I did get .5 grams gold powder from a small batch of gold fingers I had, but when I tried doing it with some gold plated pins, I have failed. I am left with a black liquid I think has a lot of base metals with the gold. I tried to dissolve the pins in DI water, sulfuric acid and sodium nitrate prills to dissolve the base metals. It was working, but taking long. Most of the base metals were dissolving and I could see a lot of golds flakes. I would filter off the solution to collect the gold flakes on a filter. Then put the solution back on the pins with another 1/2 spoonful of the sodium nitrate prills. Eventually I thought the metal that was still left in the beaker would not dissolve. So I added the filters I hade with the flakes into the beaker with mostly dissolved pins and did AR. The AR never got golden colored, just black. I filtered it thinking that would help, but did not. So I thought this is dirty solution and I could just precipitate the gold out of it. I tested with status chloride, but the solution was dark already and could not tell the results. So I just added SMB to it and waited till the next morning. I seen something on the bottom and thought it might be the gold. I was wrong. It is some kind of crystals. maybe the SMB here is what it looks like now. I hope some one can tell me what I did wrong and if I can fix this. I down loaded C.M. Hoke's book from here and just stated reading. Thank you to all who made that possible.

Welcome.
We usually use something called a Cupric Chloride etch aka AP for this.
It is cheap but takes a bit of time.
Add HCl and start bubbling air through it it will remove the Copper from under the Gold plating.

You should not have added the pins into the same as the flakes.
Now you have a very dirty AR.
SMB will drop the Gold but the leftover Nitric will make sure it immediately dissolves again.
The best option now is to cement on Copper.
Take what is left after this and dissolve again but use HCl and pool Chlorine or bleach.
If you use bleach do it cold and add just a few drops at a time.
How did you make the AR?

And continue your studies of Hoke.

 

[Shark]

Pins in AR is a bad idea. It takes way to much AR to be effective. AP is ok, but takes a lot of acids and time as well, think in terms of weeks or even months. A sulfuric cell works better, but definitely not a beginners tool. This leaves AP or Ferric Chloride with AP being the easiest for a beginner.

Refining isn't hard, but it does take some time to get a solid understanding of it. Different materials require different methods. The upside is your in the right place to learn it.

Welcome to GRF.

 

[Rick Baker]

Thank you for your response. Is this what you mean by cement it on copper? I added two pieces of copper to the solution. see pics. I made the AR by adding HCL to cover the pins, and then added 2 pipettes of nitric acid. I think the pipette is 3ml. when the reaction slowed on heat, I added another pipette full.

 

[Rick Baker]

I have some of these. see pics. I broke them to get the gold legs and the little bit of gold brazing under the die. I also have alot of eproms with the gold brazing under the die. I want to ask how I should proceed with the legs and the gold brazing under the die so I do it right this time! Thank you! Rick

 

[nickvc]

Rick welcome to the forum.
As you are finding out there real problems in doing recoveries to release your gold for refining , luckily you are in the right place to get real world advice and help , some may seem negative but it’s not personal as you will learn how to go forward.
You can master this with patience and a lot of reading and I look forward to seeing your progress.

 

[Yggdrasil]

Thank you for your response. Is this what you mean by cement it on copper? I added two pieces of copper to the solution. see pics. I made the AR by adding HCL to cover the pins, and then added 2 pipettes of nitric acid. I think the pipette is 3ml. when the reaction slowed on heat, I added another pipette full.

Pure Copper will cement out any precios metals.
They will emerge as a powder in the bottom of the vessel.
The bushing in your hand do look more like brass or bronze.
Do NOT use those.

And good to see you use gloves, they should be used at all times when handling chemicals.

 

[Rick Baker]

For sure Safety! I also wear a mask any time over by the fume hood. I made the fume hood. I don't know what the specs are for the fan or have a baffle in the back of the hood, but when I test with smoke, it is pulled in and up very well. So I think It is fine. Thank you all for the encouragement and direction. I do want to become an expert at this. I get alot of lab equipment for disposal and what are the best things to keep off of the boards? I like the eproms that I see gold. The plastic IC chips I have alot of, but when I have broken some open all I see is steel or copper legs in most of them. I have found some that look like there is gold plating on legs, but not many. Are the plastic IC chips worth it?

How long does it take to cement out the gold with copper? How do I know when it's done? Thank you, Rick

 

[Yggdrasil]

For sure Safety! I also wear a mask any time over by the fume hood. I made the fume hood. I don't know what the specs are for the fan or have a baffle in the back of the hood, but when I test with smoke, it is pulled in and up very well. So I think It is fine. Thank you all for the encouragement and direction. I do want to become an expert at this. I get alot of lab equipment for disposal and what are the best things to keep off of the boards? I like the eproms that I see gold. The plastic IC chips I have alot of, but when I have broken some open all I see is steel or copper legs in most of them. I have found some that look like there is gold plating on legs, but not many. Are the plastic IC chips worth it?

How long does it take to cement out the gold with copper? How do I know when it's done? Thank you, Rick

Have proper circulation and give it a dayish and you should be good.
To make sure polish a piece of Copper and dip it for a few seconds.
If it have some kind of powder on it you may give a bit more time.

 

[Rick Baker]

Hello, Can you tell me what this green solution means? I had a piece of copper and air bubbling in that black solution for the last 2 days, and this is what was on the bottom of the beaker when I drained off liquid. see pics. I thought , well this must be what cemented out gold looks like. I washed it with hot water and it seem to be heavy where it would stay on the bottom of the beaker (like gold powder). So then I added HCL and 2 pipettes of nitric acid then denox and filtered. Here is what I have now. Thank you for all your help. Rick

 

[Yggdrasil]

Hello, Can you tell me what this green solution means? I had a piece of copper and air bubbling in that black solution for the last 2 days, and this is what was on the bottom of the beaker when I drained off liquid. see pics. I thought , well this must be what cemented out gold looks like. I washed it with hot water and it seem to be heavy where it would stay on the bottom of the beaker (like gold powder). So then I added HCL and 2 pipettes of nitric acid then denox and filtered. Here is what I have now. Thank you for all your help. Rick

It do not look like Gold.
Gold is a fine, dark brown to cinnamon colored powder, depending on purity

 

[Rick Baker]

Hi everyone. Can I process these ends (see pic) with gold fingers? They are like ribbon cables with gold fingers on the ends. Thank you, Rick

 

[Yggdrasil]

Hi everyone. Can I process these ends (see pic) with gold fingers? They are like ribbon cables with gold fingers on the ends. Thank you, Rick

I think you can, but it might be that the plastic cover is added after plating.
That means that parts of the Gold plating will be locked in there.
So I'd process them in AP as normal and then see if they are compatible with weak AR and reprocess these specific items in that.