# Hcl/ peroxide question



## Axlrod2 (Dec 18, 2012)

I am using a hcl/ peroxide in a dish. Using to get gold off ram. I used a aquarium air pump and didn't seem to speed up the process. Would heat? A little but not to boiling?


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## maynman1751 (Dec 18, 2012)

Yes, mild heat does help. AP is a slower process. Make sure that you don't have too much material for the amount of solution.


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## nh6886 (Dec 18, 2012)

I run mine about 80-85F with a small reptile heater. One thing I have found helpful was making my bubblers out of pipettes to use the air to help agitate the solution by introducing it at the bottom. I drilled my stoppers for a tight fit and melted ten or so holes in the bulb end of the pipette with a hot pin. The results always brighten my day.


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## butcher (Dec 18, 2012)

Simple answer yes you should warm solution.

Read the copper II chloride document on Laser Steve’s web site to get a better understanding of how this leach works, and understand how to use it.

There is kind of a balancing act needed when working with this leach, between how much heat, oxidizer, free acid, and water, it is not hard to keep the solution in balance when you understand how it works, and the leach gives us visible clues to how it is doing helping us to judge what may be going on or what is needed to give desired results, this is a fairly easy leach to use when understood.

The solution if cold the action will be slowed it will still occur but can take a long time.
Heat can speeds the reactions.

Warming can help to make the reaction go faster.
But heating too strongly can give undesired results.
A little free oxygen or oxidizer in solution can give desired result.
Too much oxidizer can give problems or undesired results.

Heating also drives oxygen or chlorine gases from a solutions faster, in the case of oxygen heating strongly can drive off our oxygen needed to dissolve the copper, this can make us have to use more peroxide to get the copper dissolved, if we had a strongly heated solution and added a large dose of 3% peroxide the Highly oxidized solution can oxidize our chlorides to chlorine gas dissolved in solution, this now would begin to attack gold. Mild heating this dose of dilute peroxide would not oxidize the chlorides and dissolve gold to any extent.


We do not want to dissolve gold, with too much oxidizer in solution, our goal is to just to dissolve the copper away from the gold foil, too much oxidizer in solution which will dissolve gold, air in a cold copper II chloride solution with free HCl acid will not dissolve gold, just above room temperature a little free oxygen from air or 3% H2O2 will not dissolve gold to any extent.

But if heated strongly even the excess oxygen from air, can oxidize the chloride to form chlorine in solution which can dissolve gold, with air probably not that much gold would be dissolved that we may notice, but as we had stronger oxidizers like 3% H2O2 hydrogen peroxide this action can increase in very hot solutions.

With even stronger hydrogen peroxide we can end up changing all of the fine gold foils to dissolved gold plating back onto the copper yet undissolved, with these stronger oxidizers in solution less heat is needed to oxidize the chlorides to chlorine, with HCl and 30% H2O2 hydrogen peroxide we can dissolve gold in just a warm solution, in this case we can put gold and copper in solution together.


If too much oxidizer or hydrogen peroxide is too strong it will dissolve gold, because the oxidizer will oxidize the HCl hydrochloric acid, oxidizing the chloride in the acid to its elemental form chlorine (remove electrons from chloride), this chlorine gas in solution in turn oxidizing the gold (chlorine taking electrons from the gold atom), in the HCl the chlorides from the HCl acid now combining with the gold atom (sharing electrons) become gold chloride AuCl3 in solution, of course in this case with free elemental copper undissolved in solution this gold chloride will be reduced (gain of electron) by the copper, the gold atom now with a full shell of electrons will become elemental gold again, as these gold atoms join to form a very fine gold metal powder plating back onto the remaining copper metal or being released from the copper as the bubbling action of acids and oxidization knock them loose as fine black powder, the copper which gave its electron to the gold (to reduce the gold back to metal) this copper atom is oxidized (lose of electron) and attaches to or shares electrons with two free chloride to form copper II chloride CuCl2 dissolved in solution.


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## kadriver (Dec 18, 2012)

butcher said:


> Simple answer yes you should warm solution.
> 
> Read the copper II chloride document on Laser Steve’s web site to get a better understanding of how this leach works, and understand how to use it.



Here is steves website address: http://www.goldrecovery.us

You must log in with a user name and password given to you on the sight.

kadriver


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## lashak07 (Sep 14, 2017)

Hi
I have a crushed rack sample that has been milled and most of the silica Sand has been removed considerably except for some black Sand, lead, copper and silver present. There is also tin present. I am trying to use a chemical process to leach but i dont know what to expecting. I already have hcl, hydrogen peroxide and nitric acid. What is my best but.


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## Lino1406 (Sep 14, 2017)

Nitric acid will dissolve copper silver and lead and leave you with black sand, and tin dioxide


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