Gold Nugget 1.495 OZT - No Aqua Regia 99.67% fine

[muconium]

Wow! Thank you all for the answers.... I'm deeply embroiled in the Hoke book, but don't remember that quote. Maybe I'm not there yet.

Thanks again...

 

[muconium]

Well, I am looking with pride at a 22.79 gram button. After more exploration of Hoke and GRF, my pride was boosted a little more, as my button has the characteristic dimple, or pipe, of pure gold....

Many thanks to all who commented on this thread. Now, I am tackling the problem of silver chloride crystals. I had cemented out my silver, smelted it to shot, but decided to re-digest in 50/50 nitric acid and cement again. I wanted to wash more of the copper out, as I didn't wash it well enough after cementation. At some point I added tap water or tap water residue and ended of with gelatinous sparkly white mush.

Onward.

[edit] After more reading, I think I have silver NITRATE crystals.... So I will dissolve them and get on with the cementation process....

 

[kadriver]

This is my first post. I've been getting practice with inquarting jewelry scrap and am getting ready for the nitric washes, per Kadriver's method here. It seems like a great way to get my feet wet!

My question: Could not the final nitric wash be in undiluted, 70 percent, nitric acid? Would that not be doing all one could to ensure thorough removal of all base metals?

I have used concentrated nitric treatments but there is a tendency for popping in the relation vessel causing hot acid and gold to spit all over the place if your not careful. Using dilute nitric seems to eliminate popping all together.

Another factor is the time spent in the boiling dilute nitric acid. I have left the gold in for several hours and this seems to make for better purity at assay.

Using straight concentrated 68-70% nitric would be like using just dish soap (with no water) to wash your hands. It would get your hands clean, but adding water makes the dish soap work more efficiently.

I have stopped using concentrated nitric and always use dilute when doing these treatments.

The gold buttons turned in to the refiner have been consistent .998 at assay.

Processing the gold this way saves much time and effort, especially if it is destined for sale to the refiner.

But I always do a complete refining every now and then to maintain proficiency - or else I'll forget how to do it!

I really like doing a double refining using two different dissolutions and precipitations.

Usually first dissolve the recovered inquarted gold in AR and precip with SMB, then dissolve again using chlorine gas and precip with oxalic acid.

This double refining makes a gorgeous piece of pure gold with no traces of contamination. Gold refined this way has given 99.99 at assay from the refiner.

kadriver

 

[machiavelli976]

Hi kadriver ,
Have you ever tried to incinerate the gold sponge before new hot leaching in nitric acid ?

I've done that to a small batch of copper inquarted scrap gold and blue color of copper nitrate was revealed after two or three incineration-boiling steps.

Seems to work faster than long term nitric boiling . Never tried about silver inquarted gold but I assume it might work as well.

Marker of the method in my case was the blue of the copper nitrate . For the silver usage should be the test with table salt. Blue of copper might appear also from initial gold contaminants.

I haven't assayed my final result , yet I belive it was pretty close to yours. Maybe the PGM-s content was almost zero.

If you're tempted to try this , never get over the red dull incineration of the gold dust or sponge or whatever its consistency is. The black-brown gold must not turn yellow.

Surely , proper washing with pure water before every incineration is needed .