hydrochloric acid and peroxide turned blue

[urben miner]

Hello to all

I have been experimenting with hcl and peroxide, as recommended I’m re reading hokes book.
At the moment doing some small testing of the process –( small coffee glass jar) I have been putting in all kind of different gold plated items (may be not a good idea)

My question: in the beginning the solution turned green, at one point there were white crystals (copper salts) on the bottom so I added hcl, and they dissolved.
Now the solution is blue! what’s going on?

(I have searched the form before posting, may be I missed)

Thank you
UrbenMiner

 

[Martijn]

You will not create copper sulfate with AP. Cu2Cl can be blue.
I think its from low concentrations because i only see it in rinsing water. Maybe this also occurs in higher HCL concentrations.
The dry copper chloride dihydrate is also blue.

https://en.wikipedia.org/wiki/Copper(II)_chloride
I see you edited your post. So the sulphate comment is n.a.

 

[butcher]

The cupric chloride etching process explained. other base metals more reactive than copper will also react with this solution...[ATTACH type="full" alt="cupric chloride etch.

pdf"]0[/ATTACH]

The Reactivity series of metals can also come into play when you have a metal dissolved in solution as ions and you also have a more reactive undissolved metal. How metals can be reagent to displace a metal or a group of metal from solution, the understanding of these chemical properties or principles can be extremely helpful in understanding what is happening in solutions in recovery processes, refining processes, waste treatment, as well as helping you understand the chemical reactions involved that we work within this field.

https://en.wikipedia.org/wiki/Reactivity_series

http://www.docbrown.info/page03/Reactivity.htm

 

[urben miner]

Thank You Martijn and butcher

will go over the information and try to understand it

again Thanx

 

[butcher]

Cobalt ions in a chloride solution as cobalt II chloride can be dark blue/violet purple if diluted with water the solution will change to pink, adding HCl will again form the blue solution this can be repeated on and on.


cobalt is used in several alloys or metals, things like cutting tools drill bits saw or knife blades, in other super alloys like nickel-cobalt alloys, or with beryllium-cobalt alloys...

https://en.wikipedia.org/wiki/Cobalt-chrome
https://www.ferralloy.com/cobalt-need-know-alloys/

This reaction may be a way to determine if the color is coming from cobalt, along with some displacement reactions?
https://www-chem.ucsd.edu/undergraduate/teaching-labs/demos/demo5.html


heating test for the (invisible ink) reaction possible indicator?


https://en.wikipedia.org/wiki/Cobalt(II)_chloride


More.

http://chubbyrevision-a2level.weebly.com/the-transition-metals.html

https://www.google.com/search?q=test+for+cobalt+in+solution&source=lmns&bih=881&biw=1280&hl=en-GB&sa=X&ved=2ahUKEwjD7Outmv7tAhWMl54KHYL4A-UQ_AUoAHoECAEQAA

 

[urben miner]

Hello to all

Update on my hydrochloric acid and peroxide turned blue

After reading all the information given, I came to the conclusion that the blue color wasn't due to "Cobolt"
so I added some more hcl - greenish color returned

Cobolt is used in high friction places, my gold plated is just pins

as a result I have decided to take things to next level. Currently dissolving gold plated items in hcl+peroxide with a bubler. seems to be going well

now the hcl+ peroxide has gone brown - any idea as to why?

 

[FrugalRefiner]

It turns brown when it is saturated with copper. Just keep bubbling air through it and it will continue to work.

Dave

 

[urben miner]

It turns brown when it is saturated with copper. Just keep bubbling air through it and it will continue to work.

Dave

Thanks Dave!

 

[urben miner]

Hi to all

Update to my acid + peroxide

It seems that the solution is saturated with copper, there is still gold plating to be removed.
(in the attached pic you can see the solution frothed, on closer examination there is greenish color floating)

Not sure what the next course of action should be?

Filter the solution with hcl (get the gold out) and then continue with a fresh acid + peroxide solution? And cement the copper out from solution with iron

Or add hcl to the solution ? to continue dissolving ?

Any recommendations or advice?

Thanks

 

[butcher]

From the picture and your description I say you should just put away the chemicals and this mess for the time being, and spend more time studying before attempting to recover gold, you do not understand enough to prosper at this point, you need to educate your self more on the subject otherwise you are likely to just jump from one mess to another mess losing your gold in the processes.

The picture looks like a bucket of sludge, a big mess, looks like a lot of iron was dissolved, the mess looks nothing like a cupric or cuprous chloride solution or leach, looks more like sludge of metals including hydrolyzed iron salts, if there is gold in this mess it is more trouble than it is worth to recover it.

Let the solution settle as much as possible, decanting the solution and filtering it, test it for gold (I highly doubt any gold is in solution, I suspect filtering will be very difficult (probably full of tin or other metals making filtering difficult).

The sludge can then be treated with HCl (no oxidizer at first) to dissolve anything that is soluble in the acid. iron hydroxide will not dissolve, other ferrous salts will as well as any copper salts, keep this up until you do not get any more reaction to the HCl acid.

Decanting solution from the sludge (you can test the solution for gold should not be any in solution at this point).

This should leave you with a sludge of iron hydroxide, silver chloride if any, and any gold if involved, and any metals that will not dissolve in HCl.

Now you can add HCl with an oxidizer to dissolve any gold or other metals that will dissolve in this solution (iron hydroxide will not dissolve to any extent, silver chloride is pretty much insoluble and would be left behind in the iron sludge.

After letting it settle you can decant the solution, then remove the oxidizer from the solution, you can then test the solution for gold, then add a clean bar of copper to cement the gold from the solution,

redissolve the gold if any and precipitate it, redissolve the gold and precipitate it second refining, wash the gold, melt the gold.

 

[urben miner]

“ From the picture and your description I say you should just put away the chemicals and this mess for the time being, and spend more time studying before attempting to recover gold, you do not understand enough to prosper at this point, you need to educate yourself more on the subject otherwise you are likely to just jump from one mess to another mess losing your gold in the processes.“


I completely agree! Way out of my depth! Thank you butcher, sincerely


While I was searching through the site looking for answers to what was happening, I came across this post.

I STRONGLY ADVISE EVERYONE READING AND IS A NOVICE LIKE ME TO READ THIS

Why Can't I Ask a Simple Question and get a Simple Answer?

Butcher thank you, I will try what you suggested and hopefully manage to recover the rest of the gold. At that point solely work on getting the solution to a point that I can dispose of it responsibly.

 

[butcher]

Hoke's book has some getting acquainted experiments, that are very helpful in understanding what goes on with metals and acids.

Study the process you plan to use, gain as much understanding as possible, then try some small experiments to get a better understanding of what you have read about or seen on youtube.

You can use these same types of experiments in other areas you work to gain a better understanding of those processes. Doing these small experiments on your own with the cupric chloride leach and the different metals can help you to see what happens, you can do the small experiments with different alloys, different concentrations, different oxidation-reduction potentials of the solution (how much oxidizer added), or with using different oxidizers Air, H2O2 Ozone, sodium hypochlorite and so on, how the solution reacts to dilution with water, what happens when the pH changes.

Trying the experiments with other processes such as how different, metal reacts to the ferric leach, aqua regia...

In the testing for metal ions in the solution set yourself up with different small experiments, different concentrations of metal, and different concentrations of dilution, testing to see how oxidizer affects the tests, how the oxidation potential of the solution changes the reduction of metals. how does removing or adding bleach or nitric affect the test. How sulfamic acid or how urea carbamide reacts to change the test results of the solution...
Make up some testing solutions to test your stannous chloride to verify it is still good.