Author Topic: Making Gold Chloride  (Read 16229 times)

Offline cfnisbet

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Re: Making Gold Chloride
« Reply #15 on: October 08, 2015, 12:37:01 PM »
Burn the paper.

You will be left with a tiny granule of molten Gold.

JaWa

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Re: Making Gold Chloride
« Reply #16 on: October 10, 2015, 12:40:54 AM »
How about just transferring the mud/residue to your reaction vessel for the next reaction.

tseax

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Re: Making Gold Chloride
« Reply #17 on: October 10, 2015, 01:15:10 AM »
How about just transferring the mud/residue to your reaction vessel for the next reaction.
I considered that first.  Seemed the easiest way to deal with the precipitate. Then I noticed particles floating at all levels of the solution from which I intended to make colloidal gold a la microwave. So the solution has now been filtered and a nice glittery filter paper is waiting for a torch and crucible, and maybe some borax to keep things in the dish. I notice, however, more gold dust has settled to the bottom of the gold chloride jar. So this could be an ongoing effort till the gold chloride is gone. And I still don't know why the gold came out of solution. Without knowing this I'm not encouraged to make gold chloride in the future.

low_tech

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Re: Making Gold Chloride
« Reply #18 on: October 13, 2015, 12:12:19 AM »
Hydrogen peroxide is a reducing agent for gold in certain concentrations.  if your mixture ran out of gold or hcl before using up the h2o2, you would have leftover h2o2.  This might be the problem. 

^this

add a little more peroxide and you will see those little flecks bubbling and disappearing.

low_tech

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Re: Making Gold Chloride
« Reply #19 on: October 14, 2015, 11:11:54 PM »
this is my technique for making colloidal gold out of AuCl made with HCl and H2O2...it is a little less forgiving than Kephra's technique using known concentrations and quantities of NaCO3, AuCL and maltrodextrin.

1L water at room temp, add AuCl and maltrodextrin in normal amounts


microwave to about 160 F,, stir and add NaCo3 until you get a purplish color change at the top of the vortex in hot water, gold, maltodextrin solution...add a little more NaCO3 and return to microwave for about a minute...should be pretty ruby red and good to go.


this order of steps gives reliable results for me, took me a little experimenting to get consistently good results using the home made AuCl.  I had some purple batches and some batches that never formed colloids


tseax

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Re: Making Gold Chloride
« Reply #20 on: October 15, 2015, 03:30:24 AM »
Hydrogen peroxide is a reducing agent for gold in certain concentrations.  if your mixture ran out of gold or hcl before using up the h2o2, you would have leftover h2o2.  This might be the problem.
OK, so H202 was not used up before I added H2O to bring to a 1.5% concentration. But then there's this:
add a little more peroxide and you will see those little flecks bubbling and disappearing.
So, get rid of H202 next time around, or add MORE peroxide this time to fix the leftover peroxide problem.  Hmmm... ???
I'll try your suggestion next time wg, and yours tomorrow low-tech.

Offline kephra

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Re: Making Gold Chloride
« Reply #21 on: October 15, 2015, 02:04:22 PM »
Yes, I am interested to know what happens.
Often when I made colloidal gold by electrolysis, there would be gold flakes on the surface of the water.  My guess is that it was caused by the surface tension concentrating the nanoparticles there to the point where they agglomerated, but I have no way to verify that.

Do you know the pH of your gold chloride?
There is the unknown and the unknowable.  It's a wise man who knows the difference.

tseax

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Re: Making Gold Chloride
« Reply #22 on: October 15, 2015, 11:38:32 PM »
pH reads zero k.

Offline kephra

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Re: Making Gold Chloride
« Reply #23 on: October 15, 2015, 11:45:41 PM »
Wow, its all acid!  Did you boil off the HCL yet, or is that just after dissolving the gold?
There is the unknown and the unknowable.  It's a wise man who knows the difference.

tseax

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Re: Making Gold Chloride
« Reply #24 on: October 16, 2015, 12:25:12 AM »
Wow, its all acid!  Did you boil off the HCL yet, or is that just after dissolving the gold?
The gold was dissolved in 5 mL of HCl, on a hotplate, in a 100 mL graduated cylinder. Afterwards water was added to reach concentration.

Below is the start point of the "add H2O2" experiment to dissolve gold precipitate:


Here is a reaction to the H2O2:


Here is the resulting heavy precipitate:

...which just got worse as the solution became less yellow and more clear:


k, can you tell me more about this "boiling off the HCl" method? As in, how do I know when this is accomplished during boiling since the result is Chloroauric acid (one would hope) anyway?

Offline kephra

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Re: Making Gold Chloride
« Reply #25 on: October 16, 2015, 01:34:35 AM »
First, I want to be clear that I have not performed the procedure.  It was one of David Hudson's procedures for making monatomic gold.

HCl is actually a gas, and by boiling the gold chloride solution, you can boil off the HCl as gas.  Do not boil it dry though, just to wet sludge.  Then the sludge is diluted again with water and boiled again.  Each time, you lose HCl.  Thats the way its supposed to work.  You absolutely need a fume hood, or do it outside, as the fumes are very very noxious.
There is the unknown and the unknowable.  It's a wise man who knows the difference.

tseax

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Re: Making Gold Chloride
« Reply #26 on: October 16, 2015, 01:51:44 AM »
First, I want to be clear that I have not performed the procedure.  It was one of David Hudson's procedures for making monatomic gold.

HCl is actually a gas, and by boiling the gold chloride solution, you can boil off the HCl as gas.  Do not boil it dry though, just to wet sludge.  Then the sludge is diluted again with water and boiled again.  Each time, you lose HCl.  Thats the way its supposed to work.  You absolutely need a fume hood, or do it outside, as the fumes are very very noxious.
Noxious is right. It was alright when I only had 5 mL in the bottom of a graduated cylinder. 100 mL (started at 400 mL) is brutal. This experiment is over.

Offline kephra

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Re: Making Gold Chloride
« Reply #27 on: October 16, 2015, 02:10:05 AM »
Yeah, this is why I think Salt Lakes gold chloride is a pretty good deal.
There is the unknown and the unknowable.  It's a wise man who knows the difference.

tseax

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Re: Making Gold Chloride
« Reply #28 on: October 16, 2015, 02:30:40 AM »
Yeah, this is why I think Salt Lakes gold chloride is a pretty good deal.
Definitely...for those in the US. Some of us are stuck with Chinese HAuCl4 crystals in wee glass tubes.

low_tech

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Re: Making Gold Chloride
« Reply #29 on: October 16, 2015, 06:00:29 PM »
what the heck was the precipitate?

did you use 9999 gold?

your reactions after adding H2O2 looked a little vigorous..too much heat, would be my guess.

I go slow and easy, little bit of reagent and a little bit of heat until I get an idea of what the reaction speed is going to be.


For any one that may try this, do be careful, and use good practices and an abundance of caution.