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Vlad
05-21-2009, 12:46 AM
I found something interesting in an ORMUS archive.

"I am trying to formulate a theory on this. I know some folks in the mining
industry. They say that if you are dissolving gold in acid and you include
additives which increase the oxidation/reduction potiential (ORP) above 500
the gold will disappear. For platinum group elements it is the same but
the ORP has to be above 900. What this means is that if you dissolve gold
in acid with an added oxidizer sufficient to to move the ORP above 500 the
gold will "disappear" from the metallic state and change into the m-state."

"There are several commercial products which miners have found that will
speed the dissolution of gold in aqua regia. They warn that you must not
use too much of these products or you will "lose" your gold. The products
that they mention are calcium hypoclhorite swimming pool/spa cleaners like
"Shock" or "Sock-It". I believe that the oxidation energy transfers to the
gold and that this helps to move it to the high spin state."

Vlad
05-21-2009, 09:04 PM
There were two interesting replies I got to that post today:

You can find two methods to do this at:

http://www.subtleenergies.com/ormus/research/goldto-m.htm
http://www.subtleenergies.com/ormus/tw/hr.htm

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The reduction potentials for various reagents used to dissolve gold follow.

For Aqua Regia, which is HCl and HNO3:

NO3- + 4H+ + 3e- -----> NO + 2 H2O E= 957 mV

For the HCl/H2O2 Method: This method uses HCl and hydrogen peroxide:

H2O2 + 2H+ + 2e- -----> 2 H2O E= 1,776 mV

For the Ozone Method: This method uses HCl and ozone:

O3 + 2H+ + 2e- -----> O2 + H2O E= 2,076 mV

For the HR Method: This method uses HCl and calcium hypochlorite which give
calcium chloride and hypochlorous acid (HClO):

HClO + H+ + e- -----> 1/2 Cl2 + H2O E= 1,611 mV

For the Perchloric Acid Method: This method uses HCl and HClO4:

ClO4- + 8H+ + 7e- -----> 1/2 Cl2 + 4 H2O E= 1,390 mV

All of the above reactions generate chlorine/chloride ion.

The oxidation potentials for gold and platinum are

Au + 4Cl- -----> AuCl4- + 3e- E= -1,002 mV

Pt + 6Cl- -----> PtCl6(-2) + 4e- E= -1,435 mV

So the ORP for the reaction of gold and aqua regia is

2Au + 8Cl- + 2NO3- + 8H+ -----> 2AuCl4- + 2NO + 4H2O
E= -45 mV

The slight negative potential of -45 mV means that energy must be added to
the reaction to get it to proceed. This can be accomplished by warming the
reaction mixture. According to the Nernst equation, E is directly
proportional to temperature. So if you increase temperature, E increases.
Hypochlorite will also speed the dissolution of gold in aqua regia because
the reduction potential of hypochlorite (1,611 mV) plus the oxidation
potential of gold (-1,002 mV) is a positive number.

The ORP for the reaction of platinum and aqua regia is

3Pt + 18Cl- + 4NO3- + 16H+ -----> 3PtCl6(-2) + 4NO + 8H2O
E= -478 mV

Hypochlorite will also speed the dissolution of platinum in aqua regia
because the reduction potential of hypochlorite (1,611 mV) plus the
oxidation potential of platinum (-1,435 mV) is a positive number.

Use HCl/O3 or HCl/H2O2 if you want to maximize the ORP of the reaction
mixture.

Mike Halat