Would this dissolve the gold...????

[malikjob07]

Dear friends, and thanks again........

First of all i have splash gold on solid copper , so i'd mixed 3 L of muriatic acid against 120 ml of hydrogen peroxide .
Well my concern is would this AP solution dissolve the spray gold ???
N.B : The amount of gold is too small around 0.3 g in 2 kg of raw material. 8)
Thanks

 

[Barren Realms 007]

That is really not even worth processing. You will spend more on chemicals than what you will recover.

 

[Eamonn]

Another point is that AP is designed to dissolve the copper and leave the gold undissolved.

 

[Geo]

Instead of starting with HCl and hydrogen peroxide, start the batch using copper(II) chloride. Make the CuCl2 first by dissolving some bare copper in the HCl and peroxide. After you have the green CuCl2, filter the solution into your reaction vessel and add your material. Bubble air through solution using an aquarium pump. The solution can be used over and over by regenerating it with fresh HCl periodically.

 

[Eamonn]

Instead of starting with HCl and hydrogen peroxide, start the batch using copper(II) chloride. Make the CuCl2 first by dissolving some bare copper in the HCl and peroxide. After you have the green CuCl2, filter the solution into your reaction vessel and add your material. Bubble air through solution using an aquarium pump. The solution can be used over and over by regenerating it with fresh HCl periodically.

Geo what is the advantage of making the copper(II)chloride first?

 

[Barren Realms 007]

Instead of starting with HCl and hydrogen peroxide, start the batch using copper(II) chloride. Make the CuCl2 first by dissolving some bare copper in the HCl and peroxide. After you have the green CuCl2, filter the solution into your reaction vessel and add your material. Bubble air through solution using an aquarium pump. The solution can be used over and over by regenerating it with fresh HCl periodically.

Geo what is the advantage of making the copper(II)chloride first?

You don't take a chance of dissolving any gold when the peroxide is mixed with the HCl.

 

[Geo]

What Barren said. There's a real chance that a beginner will dissolve gold when first trying AP. By advising people to start with copper(II) chloride takes the chance of dissolving gold out of the process.

 

[NobleMetalWorks]

Instead of starting with HCl and hydrogen peroxide, start the batch using copper(II) chloride. Make the CuCl2 first by dissolving some bare copper in the HCl and peroxide. After you have the green CuCl2, filter the solution into your reaction vessel and add your material. Bubble air through solution using an aquarium pump. The solution can be used over and over by regenerating it with fresh HCl periodically.

Geo what is the advantage of making the copper(II)chloride first?

You don't take a chance of dissolving any gold when the peroxide is mixed with the HCl.

Yes you do, specially with hydrogen peroxide. However, so long as copper is going into solution, the gold will cement out.

Scott

 

[Barren Realms 007]

Instead of starting with HCl and hydrogen peroxide, start the batch using copper(II) chloride. Make the CuCl2 first by dissolving some bare copper in the HCl and peroxide. After you have the green CuCl2, filter the solution into your reaction vessel and add your material. Bubble air through solution using an aquarium pump. The solution can be used over and over by regenerating it with fresh HCl periodically.

Geo what is the advantage of making the copper(II)chloride first?

You don't take a chance of dissolving any gold when the peroxide is mixed with the HCl.

Yes you do, specially with hydrogen peroxide. However, so long as copper is going into solution, the gold will cement out.

Scott

Scott, read the thread again,

 

[SCB]

If it´s not a complex shape with lots of plated holes and such, I would probably file or grind the gold layer off and process that instead of the whole solid copper piece..

 

[NobleMetalWorks]

If it´s not a complex shape with lots of plated holes and such, I would probably file or grind the gold layer off and process that instead of the whole solid copper piece..

Grind or file? Have you ever done this yourself?

Unless you are using jewelers file or grinder, and even if you are, high purity gold is very soft, it would tend to get caught in the teeth of a file, or in the grinder itself. Being that there is only a small amount of gold we are talking about, it would very likely be totally lost.

AP solution is probably the least expensive way of recovering the gold.

If I were the person who posted, I would cut out the pieces of copper before putting in AP solution.

Scott

 

[solar_plasma]

If the substrate is like what I am imaginating, I would try to put a little AR onto some glass wool and wipe off the gold. Or maybe trying the same with inverse AR.

This is no advice, just saying, I would try it, if it were mine and given, that the substrate is a large peace of cobber with too little gold worth to recover by other means.

 

[SCB]

If it´s not a complex shape with lots of plated holes and such, I would probably file or grind the gold layer off and process that instead of the whole solid copper piece..

Grind or file? Have you ever done this yourself?

Unless you are using jewelers file or grinder, and even if you are, high purity gold is very soft, it would tend to get caught in the teeth of a file, or in the grinder itself. Being that there is only a small amount of gold we are talking about, it would very likely be totally lost.

AP solution is probably the least expensive way of recovering the gold.

If I were the person who posted, I would cut out the pieces of copper before putting in AP solution.

Scott

Yes I have.
I had some quite big plated blocks of copper. I drilled out the holes to get the gold inside and used 100 grit wet/dry sandpaper to grind of the plating on the outside.
Then I incinerated the sand paper and digested the swarf/grindings to recover the gold for further processing.

And using a file.. Why not?
Yes, the teeth will probably steal some of your gold but that doesnt mean it´s totally lost. Recovering the gold from the file is probably cheaper and faster than disolving the entire copper blocks if they are big
Or just make a deplating cell and process them that way, I didn´t because of really bad restrictions on sulfuric in my country.

 

[Geo]

If the substrate is like what I am imaginating, I would try to put a little AR onto some glass wool and wipe off the gold. Or maybe trying the same with inverse AR.

This is no advice, just saying, I would try it, if it were mine and given, that the substrate is a large peace of cobber with too little gold worth to recover by other means.

There is a phrase that I like to say about things like this "It's like skinning a bee for it's wax". A lot of work for very little return. Depending on the weight of the piece and the type of base metal, it could be worth more selling it as scrap metal (copper) than trying to reclaim the gold. It reclaiming the gold is a must, I would opt for the CuCl2 method. It is a "set and forget" process that needs very little attention until completion. In the AP process, the base metal is dissolved leaving gold behind. In this case, it is my opinion that the base metal is worth more than the gold. Stripping the gold will leave you the base metal intact but the small amount of gold recovered will not justify the amount of work needed to reclaim it unless you are working with a truck load at a time. If it were enough material, cyanide leaching would be what I would advise.

 

[Anonymous]

It really is about time that we pooled our resources and experience, and dedicated some time to providing information on some decent surface leech processes for the members don't you think?

Dissolving loads of copper to recover a tiny amount of gold is really inefficient wouldn't everyone agree?

 

[FrugalRefiner]

Great idea Jon! Thanks for taking the lead! 8)

Dave

 

[malikjob07]

i like the interaction here ....but i was wondering :shock: if the use of aquarium pump in AP solution is better than adding hydrogen peroxide....just to accelerate the process ? :arrow:

 

[NobleMetalWorks]

i like the interaction here ....but i was wondering :shock: if the use of aquarium pump in AP solution is better than adding hydrogen peroxide....just to accelerate the process ? :arrow:

A aquarium bubbler works very well. Some aquarium stones will dissolve or fall apart in AP, just find the right one.

Personally, I only use H2O2 when first starting an AP solution, then I switch to air stones and an aquarium pump.

Scott

 

[Geo]

i like the interaction here ....but i was wondering :shock: if the use of aquarium pump in AP solution is better than adding hydrogen peroxide....just to accelerate the process ? :arrow:

Peroxide should only be used once in the process. It is added at the beginning to produce the very first bit of copper(II) chloride. HCl alone will not dissolve copper. There has to be copper chloride to dissolve copper. When you first add the hydrogen peroxide to the solution, it will dissolve a little bit of gold. It will not be much because there's so much base metal present. The electromotive series of metals tells us that copper will dissolve before gold does. Even in an oxidizing solution. You can force gold metal to dissolve in the presence of copper metal but it takes an excess of oxidizer. Since the base metal is covered in gold metal, the gold has to dissolve first so the acid can reach the base metal. If enough base metal was exposed to began with, no gold would be dissolved. This is seldom the case when working with gold plated connectors. The air pump serves two purposes. It keeps the solution oxygenated and it causes a mechanical disturbance by the bubbling action. This helps agitate the solution and the material. If you did not use an air pump to keep the solution oxygenated, you would have to add peroxide periodically and that would dissolve some gold for sure.

 

[malikjob07]

but i saw Moose Scrapper in some of his video recovering gold with only HCL and air....no use of hydrogen peroxide .....like he said " no fear of dissolving gold...

https://www.youtube.com/watch?v=Df-yBhQUMz0