[SteveE]

Hi Everyone:

I'm thinking about buying a system for gold refining from Shorinternational.

http://shorinternational.com/simplbrochure.htm

I've always thought aqua regia was the only method used to refine precious metals and now this guys claims to be able to do it safely. Anyone know what this "GC salt and odor free precipitant" is made of and how this system works?

Thanks

Steve

[Nick]

Hi Steve,

This guy is electrochemically oxidizing gold (removing its electrons) at the anode, and the GC salt is almost certainly sodium chloride.  It is easier to oxidize (i.e. dissolve) gold in the presence of chloride ion...one of the reasons why aqua regia works so well.  The cathode is on the other side of the ceramic I imagine.  The ceramic is impermeable to the gold ions, and therefore, they cannot be reduced back to metallic gold at the electrode.  The odor free precipitant is almost certainly a very weak reducing agent to convert the gold ions back into solid gold.  Gold ions are much more easily reduced than other metal ions so that is how he selectively precipitates the gold.  Nice invention.

[wilson]

I suppose GC stands for Gold Chloride?

It claims it can refine platinum too. How is that possible? If there are no Pt ions in solution, can Pt be oxidised?

[butcher]

I refine my own gold from electronics, jewelry, and glass objects, make my own chemicals from fertilizers,  if plated heavy i use a homemade nitric acid--- sodiumnitrate (Na(NO3)2) and battery acid (H2SO4) 1:1 ratio, I use store bought H2SO4 no lead,this gives HNO3 + Na SO4 +h2O IF WITH OTHER METALS SEPERATE AS MUCH AS POSSIBLE CUT OPEN PARTS TO EXPOSE BASE METALS SMALL PIECES BEST  OUTSIDE ON HOT PLATE OR IN CROCKPOT PUT ACID THEN GOLD THEN SODIUM NITRATE (CAN ALSO USE AMMONIUM NITRATE FERTILIZER OR POTTASIUM NITRATE SOLD AS STUMP REMOVER) BOIL THIS CAUTION STAY CLEAR OF FUMES AND NOT INSIDE ECT ALSO VERY CORROSIVE TO METALS ECT. THIS WILL MAKE A NITRIC THAT WILL DISOLVE COPPER AND OTHER METALS LEAVING GOLD IN A SALT METAL BLUE SOLUTION COPPER SUFATE AND GOLD FLAKES,   ADD WATER TILL ALL SALT IN LIQIUD, LET GOLD SETTLE TAKE SYRYNGE REMOVE BLUE LIQUID, SAVE FOR COPPER ELECTROLISIS OR ADD LESSER ACTIVE METAL LIKE ZINK TO REMOVE COPPER AND BAKING SODA TO NEUTRALIZE. IF HAD SILVER IN METAL NaCL or table salt will make it precipitate out as white cottage cheese powder --- can take these metals and add lil bit borax soap as flux and a torch and melt back to metals ---------or can make Aqua regia to disolve gold by using the above nitrate fertilizers and hydrochloric acid ( muratic used to clean concrete,,  Na(NO3)2 + HCL +Au = HAuCL4 + NO2 +H2O this disolves all metals including the gold,,, boil this to remove nitric acid as  red cloud caution do outside do not breath ect.boil till almost but not dry adding a lil HCL acid to wet do this three times then add 10 times the amount in water distilled (silver if any will precipitate as white powder  if doesn't and you know you have silver lil NaCL(table salt) will precipitate. - then make a solution of ferrous(Iron) sulfate from old cut up transformer iron or brads nails ect and sulfuric acid and seven times water wait till this give greenish solution --- this added to aqua regia gold solution that nitric boiled off- will make gold fall to bottom as a brown powder let settle 24hrs, remove liquid solution of copper or other metals take brown dried powder lil borax and torch and turn back to gold, solution drop the copper ect as above with zink ect and neutralize with baking soda or caustic soda lye ect.  tried with storebought chemicals and they cost more than you can get for the gold ,, this is dangerous chemistry so if you do this be very careful and if yer Young get your dad , uncle or teacher ect to help they would love to learn this too, also study this first dont just read something on the intranet and believe it alot of      people dont know what they are talking about, learn it study and see$$$$ 

[geubrina]

How about this procedure? :

http://rockyledgemining.tripod.com/solventexchange.html

Procedure:

1.  Prepare 1 parts of clear leach by filtering pregnant solution through a # 42 Whatman filter into the beaker marked Gold. [NOTE: You may rinse the debris from the filtering back into your original leaching container to retain any unleached metals.]

2.  Add 1 parts of distilled water and stir manually (stirring rod or agitating the beaker)

3.  Add 2 parts of CDE 5 Gold Collector.

4.  Place beaker on a magnetic stirring hotplate, place stir bar in the beaker and agitate strongly for 45 minutes at 98 degrees F.

 5.  Transfer the solution to a separatory funnel and allow it to settle into two layers. The gold will be in the top layer.

6.  Drain the bottom layer into a beaker marked “Pregnant solution minus Au” and set it aside. [This “waste” liquid will be processed later for possible platinum group metals. The procedure is the same, but the collectors and strippers and different for each metal. Supplies may be purchased from Rocky Ledge.]

7.  Place the CDE 5 into a beaker and add an equal amount of CDE 9 gold separator.

 8.  Agitate vigorously while bringing the solution to 180 F. This could take as long as 90 minutes depending on the volume as well as your heating and stirring equipment.

 9.  As the temperature rises a color change in the liquid will become apparent.

10.  At approximately 180 F any gold present will appear to be “black” particulate floating in the solution. When the color is no longer modifying stop the heating and stirring.

11.  Place the solution into a separatory funnel and allow to separate.

12.  Drain the bottom solution through a # 42 Whatman filter to collect the gold particulate.

13.  Rinse the particulate from the filter paper into an appropriate beaker. Add a small amount of HCL to the liquid and stir vigorously.

14.  An amount of the gold will be “in the vortex” created by the stirring. Slowly add isopropyl alcohol—store-bought cheap rubbing alcohol—to the dilute HCL solution. When the mix is approximately 50/50 the gold will fall out of the vortex and settle in the bottom. 

15.  Air dry the powder in a protected area. You can be assured the material remaining is an ultra high quality gold in sponge form. This sponge gold is sale-able as it is.

Can anybody explain above procedure?

[Arkcon]

Briefly, like Nick explained above, aqua regia is not required to dissolve gold or platinum.  Chlorine forms stable complexes with gold and platinum, but sodium chloride or hydrochloric acid don't have the oxidizing power to attack noble metals.  If chloride anion is present, you can use another oxidizer, like:

1). Aqua regia: (direct cut-n-paste from wikipedia)
for gold:
    Au (s) + 3 NO3- (aq) + 6 H+ (aq) → Au3+ (aq) + 3 NO2 (g) + 3 H2O (l) and
    Au3+ (aq) + 4 Cl- (aq) → AuCl4- (aq).

for platinum:
    Pt (s) + 4 NO 3- (aq) + 8 H+ (aq) → Pt4+ (aq) + 4 NO2 (g) + 4 H2O (l)

    3Pt (s) + 4 NO 3- (aq) + 16 H+ (aq) → 3Pt4+ (aq) + 4 NO (g) + 8 H2O (l)

The oxidized platinum ion then reacts with chloride ions resulting in the chloroplatinate ion.

    Pt4+ (aq) + 6 Cl- (aq) → PtCl62- (aq)

Note: we don't get just one reaction with aqua regia.  The alchemists are (mostly) gone now, so we don't have to think of aqua regia as a homogeneous magical substance that just eats the noble metals, but rather as a mixture of a variety of anions with unique properties, to form complexes with gold and platinum.

2).  We can reduce electrochemically.  Anyone who wants to, may take a gold ring off their finger, and drop it in a solution of table salt in water -- to no effect.  But, wire that ring to then anode of a battery -- and watch the ring disappear.

3).  Other oxidizers:  I don't know what the organic oxidizer in the commercial refining blurb above is.  It's not meant for chemists, but rather backyard gold miners.  A cheap gold ring may even dissolve in household chlorine bleach, the less noble metals in the alloy setup tiny electrochemical cells, that don't provide the oxidizing power alone, but together with the hypochlorous ion, can attack gold.