 |
 |
| Make your own Super Leach! |
Halogen Leaching procedures
This is an all-round leach, to be used in conjunction with an ORP Meter,
(Oxygen-Reduction_Potential) to govern the amount of time necessary to oxidize the
precious metals into solution.
*Note: This formulation was developed over 45 years ago, commonly used in the mining
industry, but seldom revealed to outsiders, recorded in the Mine offices of Santa Gertrudes,
Baja Norte, B.C., Mexico, "Alluvias de Oro"
With your ORP meter, keep this mixture between 400mv and 900 mv to avoid co-extracting
iron and other base metals. If you wish to run your mixture hotter to speed and enhance
extraction, say above 1200 mv., it is perfectly permissible, but if you have iron, pre-treat, as
below:
Removing Iron
To remove Iron, pre-wash the ground-up ore with Citric acid...a relatively cheap chemical
available in bulk that is bio-degradable. Make up a mixture of up to 33% citric acid crystals,
and the balance hot water.
This mix can be poured over the ground ore in filters, mixed with ore in a container or used in
your ball mill while grinding.
The liquid mixture is then filtered to recover the solids..the liquid now contains dissolved iron.
Iron can be recovered by pouring the liquid filtrate through "Greensand", or discarding both
into the environment, after diluting it, as it is good for iron-loving, and acid-loving plants.
Leach Mix
Returning to your ore, now make up the leach mix, following this formula;
To each 2 gallons of de-ionized water, or softened (if you have it), heat it to near boiling,
adding as much common salt (rock salt is OK) as it will absorb.
Allow it to cool.
Draw off 7/8 of the salt-saturated water.
This is the basis of the leach.
Now add 1 to 4 ounces of 7% Iodine to the salt water, depending on how strong you want it. It
will turn the leach purple to red color.
Add 1/2 to 1 pint of Nitric acid...again, depending on strength desired.
This then, is your own private "Super Leach".
This leach will dissolve all precious metals as rapidly as cyanide, as long as you keep the
ORP high, as I outlined above. Not all ores are the same, like snowflakes, so each one must
be tested with varying degrees of the leach.
Ore Preparation
The ore you are using must be ground fine enough to allow the leach to
penetrate and contact all parts of the gold and precious metals, in order to dissolve them.
This may require a fine grind to 200 mesh or more to release all values. A very reasonable
"Ball Mill" can be made from a poly-
barrel cement mixer. Northern Tools has one for about $250. Add a couple of gallons of
smooth river rock or quartz to do the grinding, toss in 10-15 lbs. ore, and "Voilà"...A Ball Mill!
If using a mixer, the leach can actually be added at this point while grinding it down, if you
are satisfied with prior tests.
http://www.northerntool.com/
Leaching
Having mixed 1 part ore and 6 parts leach together, the Nitric acid in the leach will be
consumed and lose some potency. You can raise the ORP several points, adding HCL
(Muriatic) acid in small amounts as this happens, replacing the Nitric Acid loss, and adding a
new dimension to the leach power, helping the high end of the ORP scale, as the lower end
at 400 mv is covered by the Iodine. Do not add too much HCL, or you will make Aqua Regia,
dragging other, unwanted metals out into solution.
When additions of acid in the leaching process no longer extract any more Gold or Precious
metals... It is finished (we will cover that testing in the Leaching manual) it is time to stop, and
drain off the Pregnant liquor, containing the metal values.
*Don't leave the leach too long, or it may re-precipitate back onto the ore.--------although this
is less likely to happen using this leach formulation, owing to the iodine.
This leach will rapidly extract Precious Metals from prepared ores, slimes and sediments.
Gold, Platinums, Silver and rare earth metals will dissolve in a fashion known as the
"Electrical Ladder"..The native charge that all metals possess ...Gold heading the list at +
1.36 volts.
Chemical dissolution is the act of this electro-motive force, temporarily applied to put all
particles into solution, from which we select what we want
through precipitation.
This is an all-round leach, to be used in conjunction with an ORP Meter,
(Oxygen-Reduction_Potential) to govern the amount of time necessary to oxidize the
precious metals into solution.
*Note: This formulation was developed over 45 years ago, commonly used in the mining
industry, but seldom revealed to outsiders, recorded in the Mine offices of Santa Gertrudes,
Baja Norte, B.C., Mexico, "Alluvias de Oro"
With your ORP meter, keep this mixture between 400mv and 900 mv to avoid co-extracting
iron and other base metals. If you wish to run your mixture hotter to speed and enhance
extraction, say above 1200 mv., it is perfectly permissible, but if you have iron, pre-treat, as
below:
Removing Iron
To remove Iron, pre-wash the ground-up ore with Citric acid...a relatively cheap chemical
available in bulk that is bio-degradable. Make up a mixture of up to 33% citric acid crystals,
and the balance hot water.
This mix can be poured over the ground ore in filters, mixed with ore in a container or used in
your ball mill while grinding.
The liquid mixture is then filtered to recover the solids..the liquid now contains dissolved iron.
Iron can be recovered by pouring the liquid filtrate through "Greensand", or discarding both
into the environment, after diluting it, as it is good for iron-loving, and acid-loving plants.
Leach Mix
Returning to your ore, now make up the leach mix, following this formula;
To each 2 gallons of de-ionized water, or softened (if you have it), heat it to near boiling,
adding as much common salt (rock salt is OK) as it will absorb.
Allow it to cool.
Draw off 7/8 of the salt-saturated water.
This is the basis of the leach.
Now add 1 to 4 ounces of 7% Iodine to the salt water, depending on how strong you want it. It
will turn the leach purple to red color.
Add 1/2 to 1 pint of Nitric acid...again, depending on strength desired.
This then, is your own private "Super Leach".
This leach will dissolve all precious metals as rapidly as cyanide, as long as you keep the
ORP high, as I outlined above. Not all ores are the same, like snowflakes, so each one must
be tested with varying degrees of the leach.
Ore Preparation
The ore you are using must be ground fine enough to allow the leach to
penetrate and contact all parts of the gold and precious metals, in order to dissolve them.
This may require a fine grind to 200 mesh or more to release all values. A very reasonable
"Ball Mill" can be made from a poly-
barrel cement mixer. Northern Tools has one for about $250. Add a couple of gallons of
smooth river rock or quartz to do the grinding, toss in 10-15 lbs. ore, and "Voilà"...A Ball Mill!
If using a mixer, the leach can actually be added at this point while grinding it down, if you
are satisfied with prior tests.
http://www.northerntool.com/
Leaching
Having mixed 1 part ore and 6 parts leach together, the Nitric acid in the leach will be
consumed and lose some potency. You can raise the ORP several points, adding HCL
(Muriatic) acid in small amounts as this happens, replacing the Nitric Acid loss, and adding a
new dimension to the leach power, helping the high end of the ORP scale, as the lower end
at 400 mv is covered by the Iodine. Do not add too much HCL, or you will make Aqua Regia,
dragging other, unwanted metals out into solution.
When additions of acid in the leaching process no longer extract any more Gold or Precious
metals... It is finished (we will cover that testing in the Leaching manual) it is time to stop, and
drain off the Pregnant liquor, containing the metal values.
*Don't leave the leach too long, or it may re-precipitate back onto the ore.--------although this
is less likely to happen using this leach formulation, owing to the iodine.
This leach will rapidly extract Precious Metals from prepared ores, slimes and sediments.
Gold, Platinums, Silver and rare earth metals will dissolve in a fashion known as the
"Electrical Ladder"..The native charge that all metals possess ...Gold heading the list at +
1.36 volts.
Chemical dissolution is the act of this electro-motive force, temporarily applied to put all
particles into solution, from which we select what we want
through precipitation.
| Updated 11/5/2006 |