My gold is not dissolving in aqua regia

[Jkessans]

I have a small amount of left over gold powder tiny gold nuggets left over from all my gold refining processes and pours. I am trying to dissolve all this material in an aqua regia solution. The total is around 14 grams. I put them in a beaker, cover them with 200 Ml of HCL and pipped in a total of 10 ML over time. It has been and 90 minutes and the little pure gold nuggets have not dissolved. Does it talk long? I’m stumped? Anyone know what the problem could be?

 

[Golddigger76]

Have you tried heating it ?

 

[Yggdrasil]

I have a small amount of left over gold powder tiny gold nuggets left over from all my gold refining processes and pours. I am trying to dissolve all this material in an aqua regia solution. The total is around 14 grams. I put them in a beaker, cover them with 200 Ml of HCL and pipped in a total of 10 ML over time. It has been and 90 minutes and the little pure gold nuggets have not dissolved. Does it talk long? I’m stumped? Anyone know what the problem could be?

As Golddigger says you need to heat it to almost boiling to have a relatively fast reaction.
Make sure to have plenty of headroom in the beaker.
It would have been enough to cover the button with HCl, you are using too much in my mind.

 

[stoneware]

I have a small amount of left over gold powder tiny gold nuggets left over from all my gold refining processes and pours. I am trying to dissolve all this material in an aqua regia solution. The total is around 14 grams. I put them in a beaker, cover them with 200 Ml of HCL and pipped in a total of 10 ML over time. It has been and 90 minutes and the little pure gold nuggets have not dissolved. Does it talk long? I’m stumped? Anyone know what the problem could be?

Inquart and heat.

 

[Jkessans]

I was boiling it. Nothing in that beaker was dissolved.

 

[Golddigger76]

Are you using 31% hydrochloric acid or green hydrochloric ?
You wrote that you added 10ml over time, was that 10ml of nitric acid ?
If so it will probably take more to dissolve 14 grams of gold.

 

[Golddigger76]

Also have you tested with stannous chloride to see if any gold has gone into solution ?

 

[Yggdrasil]

Inquart and heat.

No need to inquart when you have pure Gold powder.

 

[Yggdrasil]

I was boiling it. Nothing in that beaker was dissolved.

If the nugget is placer it is fully possible that it has too much Silver in it.
If so you need to inquart.
Do the powder dissolve?
If not, it can be too dilute or the Nitric or HCl are not what you think.
And last but not the least Stannous test as Golddigger say, it is our eyes in the refining world.

I cant remember if I gave you this before but I'll give it now at least:

We ask our new members to do 3 things.
1. Read C.M. Hokes book on refining jewelers scrap, it gives an easy introduction to the most important chemistry regarding refining.
It is free here on the forum: Screen Readable Copy of Hoke's Book
2. Then read the safety section of the forum: Safety
3. And then read about "Dealing with waste" in the forum: Dealing with Waste

Suggested reading: The Library

 

[stoneware]

No need to inquart when you have pure Gold powder.

From the first line of the OP's post, no pictures so we have no indea of what his definition of tiny nuggets is.

I have a small amount of left over gold powder tiny gold nuggets left over from all my gold refining processes and pours.