time necessary to dissolve e-scrap

[James White]

I have some gold plated connectors that are separate from any plastic or other contaminants. (picture attached) problem is after several days the connectors have released some gold sediment but they are mostly still intact. The acid is still acting on the base metal evidenced by bubble action and tiny flakes of material floating up and then sinking. (each connector is approx 1/2" long)

 

[Shark]

Picture’s need to be in jpeg or similar format. The forum can’t show heic format as it is an apple proprietary format and needs more software to work with it.

Curious as to what acid you’re using also.

 

[Yggdrasil]

I have some gold plated connectors that are separate from any plastic or other contaminants. (picture attached) problem is after several days the connectors have released some gold sediment but they are mostly still intact. The acid is still acting on the base metal evidenced by bubble action and tiny flakes of material floating up and then sinking. (each connector is approx 1/2" long)

Welcome to us.
First a couple of things.
How long is a rope?
As your question this can not be answered unless we have much more information.
So please add some more information.
Next I for one do not press on anything unknown on the net
and your proprietary Apple format pictures do not show in the forum.
Please convert to JPG and re upload.

Here are something to study for you:

We ask our new members to do 3 things.
1. Read C.M. Hokes book on refining jewelers scrap, it gives an easy introduction to the most important chemistry regarding refining.
It is free here on the forum: https://goldrefiningforum.com/phpBB3/viewtopic.php?f=54&t=19798
2. Then read the safety section of the forum: https://goldrefiningforum.com/forums/safety.47/
3. And then read about "Dealing with waste" in the forum: https://goldrefiningforum.com/threads/dealing-with-waste.10539/

Suggested reading:
https://goldrefiningforum.com/forums/the-library.101/
https://goldrefiningforum.com/threads/when-in-doubt-cement-it-out.30236/
https://goldrefiningforum.com/threa...le-read-this-before-you-post-about-ore.33333/


Forum rules is here.
https://goldrefiningforum.com/threads/gold-refining-forum-rules.31182/

 

[Golddigger76]

Here's his picture that he tried to post, I can open it up with my android galaxy with photos.

 

[James White]

100 grams of connectors in chemical bath of 2 parts HCl (31%) in H2O2 (3%) for 7 days. Have downloaded book and will continue research.

 

[Shark]

HCl and peroxide at a 2:1 ratio is very heavy on the peroxide. I prefer to use HCl with an aquarium air pump. To much H2O2 will cause some gold to dissolve and often panic new users into thinking they have lost their gold. Pins are slow in CuCl2, often miss named as AP, or Acid/Peroxide. It will work but takes quite a bit of time. Quality pins, as yours appear to be, are often ran in a sulfuric cell, if there is enough of them, it may even be quicker. A cell is also a pretty steep learning curve for many.

Edit for spelling and punctuation

 

[James White]

Goldigger 76 - thnaks for the conversion

 

[James White]

Shark - I have several pounds of this material. Will look into the sulfuric cell option keeping your cautionary in mind. Thanks. Love the quotes...

 

[Golddigger76]

They are nice heavy plated gold pins
and even if you cut them in half it's still going to take several days to digest the base metals.
I have some very similar pins in AP that are about 5 days in on low heat, my aquarium pump quit on me about a week ago otherwise I would have air bubbling through them.

My acid was left over from another gold pin recovery so it already had plenty of copper in it to start the etching process.

Once you get a decent amount of copper chloride built up in your acid your base metals will start dissolving more and more each day so don't get discouraged if it takes longer than you expected, it's quite a bit slower than dissolving with nitric but it is cheap and you can reuse your acid on your next batch of pins or gold plated items.

After 5 days my acid is very dark green and the foils are releasing but the base metals are not fully dissolved, maybe half way, a aquarium air bubbler will speed up the process and if your acid starts looking black then add a little more hydrochloric.

 

[Ag and Au]

I too have gathered several pounds of this type of material. I was planning on doing a test batch of 1 Kilo into a large beaker with leftover CuCl2 (AP) and an air bubbler once the weather improves. Are you guys thinking weeks or months to fully dissolve the base metal?

 

[Golddigger76]

I too have gathered several pounds of this type of material. I was planning on doing a test batch of 1 Kilo into a large beaker with leftover CuCl2 (AP) and an air bubbler once the weather improves. Are you guys thinking weeks or months to fully dissolve the base metal?

For a kilo it can be done in 2 weeks if you start with used AP solution, if you start with new hydrochloric acid it may take longer but the aquarium bubbler will speed it up.
I also use low heat and it helps as well

 

[Alondro]

They are nice heavy plated gold pins
and even if you cut them in half it's still going to take several days to digest the base metals.
I have some very similar pins in AP that are about 5 days in on low heat, my aquarium pump quit on me about a week ago otherwise I would have air bubbling through them.

My acid was left over from another gold pin recovery so it already had plenty of copper in it to start the etching process.

Once you get a decent amount of copper chloride built up in your acid your base metals will start dissolving more and more each day so don't get discouraged if it takes longer than you expected, it's quite a bit slower than dissolving with nitric but it is cheap and you can reuse your acid on your next batch of pins or gold plated items.

After 5 days my acid is very dark green and the foils are releasing but the base metals are not fully dissolved, maybe half way, a aquarium air bubbler will speed up the process and if your acid starts looking black then add a little more hydrochloric.

I always save some of the dark brown (full of copper chloride) used acid to jump start the next batch of plated materials.

 

[Shark]

Question.

How much CuCl2 is needed to digest a pound of pins? Just add pins and acid and let it go, with air pump if that is how you normally do it.

 

[Martijn]

Question.

How much CuCl2 is needed to digest a pound of pins? Just add pins and acid and let it go, with air pump if that is how you normally do it.

One atom of CuCl2? Plus some HCl and oxygen. For one mole of copper I think two moles of HCl?

 

[Martijn]

I too have gathered several pounds of this type of material. I was planning on doing a test batch of 1 Kilo into a large beaker with leftover CuCl2 (AP) and an air bubbler once the weather improves. Are you guys thinking weeks or months to fully dissolve the base metal?

Try a testbatch of ten pins in CuCl2, a kilo will take a month imo.
The concentrated H2SO4 stripping cell is the best option for pins for me.

 

[Yggdrasil]

One atom of CuCl2? Plus some HCl and oxygen. For one mole of copper I think two moles of HCl?

Hmm, there is no such thing as a CuCl₂ atom, it is a molecule comprised of three atoms one Cu and two Cl

 

[Shark]

I may be over (?) thinking it. One thing we never seem to see is an answer such as “put a pound of pins in a gallon of AP and give it 10 days”. CuCl2 works best with an excess of chemicals and plenty of time to allow it to do the job. The one thing I learned early on is that doing anything other than a test batch size of pins in AP is not efficient or quick. It can be done, yes, but it is a test of patience for sure.

 

[Golddigger76]

I may be over (?) thinking it. One thing we never seem to see is an answer such as “put a pound of pins in a gallon of AP and give it 10 days”. CuCl2 works best with an excess of chemicals and plenty of time to allow it to do the job. The one thing I learned early on is that doing anything other than a test batch size of pins in AP is not efficient or quick. It can be done, yes, but it is a test of patience for sure.

There's probably too many variables to give exact numbers but I'm sure that someone has taken the time to figure out how many grams of base metals per liter a standard copper chloride solution will dissolve.

I have had small batches done in as fast as a week and large batches (as in enough pins to fill a half gallon jar) that took 3 to 4 months.

It also goes faster if you're not starting with new hydrochloric acid.

The strength of peroxide also has a direct effect, seems like when I have added too much 3% peroxide it diluted the hydrochloric acid and actually slowed the process.

With or without heat also makes a difference, and so does with or without air bubbling through it does.

It's not a fast process only cheap and reusable.

 

[kurtak]

There's probably too many variables to give exact numbers but I'm sure that someone has taken the time to figure out how many grams of base metals per liter a standard copper chloride solution will dissolve.

I have had small batches done in as fast as a week and large batches (as in enough pins to fill a half gallon jar) that took 3 to 4 months.

It also goes faster if you're not starting with new hydrochloric acid.

The strength of peroxide also has a direct effect, seems like when I have added too much 3% peroxide it diluted the hydrochloric acid and actually slowed the process.

With or without heat also makes a difference, and so does with or without air bubbling through it does.

It's not a fast process only cheap and reusable.

The thickness of the plating also factors in - it takes long for the acid to get under thicker plating to start dissolving base metal - especially true with CuCl2

Kurt

 

[kurtak]

Concerning speed ------

Nitric acid = done in one day --- poor mans nitric would work

Cyanide stripping = done in one day

Kurt