Jeweler’s Dirt

Hi folks,

I have been experimenting on some jeweler’s dirt I got from my local small town jewelry store. This is the dirt that was from his buffing wheel area. I received approximately 4.9oz. and it contains a lot of buffing compounds and fuzz from his wheel.

I started out by sifting this dirt to remove the fuzz and larger chunks. I then ground the chunks and combined to the already sifted fine dirt. I took 1oz. of this dirt along with the fuzz and burned it down, ground it to a fine power and incinerated till it glowed orange in a dry melting dish. I then ran a magnet through the power and removed anything that stuck to it and set it aside for later.

I transferred the remaining powder to a 2L beaker and added 250ml of my cold recipe nitric acid diluted with a little distilled water. Set it on my hotplate/stirrer with a watchglass and set to a low heat and slow stir. I waited till the reaction stopped and added another 250ml of my diluted cold recipe nitric acid. After the reaction stopped I ended up with a lime green colored solution. I’m thinking good, I should have removed most of the garbage metals along with some silver.

I tested the solution with stannous in a white plastic spoon and on a filter paper. It showed very positive for gold. The color went instant jet-black. I have to assume something in the powder created an AR solution. Any idea what might have caused this???

My plan was to siphon off this solution and go straight to AR with the remaining powder in the same beaker. I have since done this and my AR was a beautiful golden yellow. Was able to control my nitric additions so no denox was needed. Have chilled with ice, filtered and dropped my gold with SMB with no problems.

Should I have started with HCL to remove my base metals? I figured nitric would do a much better job of removing the base metals but now I’m not so sure. I am now in the long process of denoxing my green solution by evaporation and addition of HCL. Any suggestions would be very much appreciated.

Thanks, Mike

http://goldrefiningforum.com/phpBB3/viewtopic.php?t=1253&start=0&postdays=0&postorder=asc&highlight=

Thanks for the link. As soon as I saw it I remembered reading that a while ago and thought oh great, now I feel stupid again . Sorry for the rehash of an old subject.

Mike

Nothing wrong with asking questions. 8)

On your nitric solution that test positive for gold you can possibly add some SMB and drop your gold as I have done in the past. You might want to take a look at this thread and see if it helps you any.

http://www.goldrefiningforum.com/phpBB3/viewtopic.php?f=49&t=6026&p=87587#p87587

Hi Folks,

Just had to let you guys know that my little jewelry dirt experiment has panned out. My local jeweler was very impressed with my return of 6.07 grams of twice refined gold from his 4.9 oz. trial bag of dirt. He has always felt that he has been way under paid by the guy that he has been dealing with. Now he knows. Too bad for the other guy because now I am going to be his refiner for all of his bench dirt in the future for a percentage of the gold. He claimed the guy that buys his dirt wouldn’t have even come close to the value of the gold I just handed him for all of his dirt. I’m going back this Friday to pick up my first batch, which looks like it will be well over 5 lbs. might be closer to 10.

He is also questioning what he’s been getting for his bench filings now too. He was talking about letting me refine his next batch of those too. :mrgreen:

I couldn’t have done this without the help and information provided by this forum. I can’t thank all of you enough for what you’ve done for me and how it’s changed my life for the better. We could be talking new career / small business for this old man. Will let you know how this next batch goes.

Thanks again

Mike

That's great news Mike, it just goes to show how honesty is the key ingredient.

These are more of the personal stories of success we should write about. Being a mentor to newbies will go a lot farther than than just a director.
Excellent job Mike, keep us updated,

Mike,
What you just experienced was precisely how I got started refining for others, and resulted in my prolonged refining career.

The first lesson I learned was that honesty was of uppermost importance. Treat the customer fairly and you have them for life.

My hat is off to you.

Harold

Emmjae
Harold was saying incinerate
sieve
boil in HCL
than AR
than usual stuff for polishing dirt with gold.
with this process if there is silver in the solution it falls to the bottom as scums than you use nitric to get the silver
Would this be a corrected summary of this process

PreciousMexpert said:

Emmjae
Harold was saying incinerate
sieve
boil in HCL
than AR
than usual stuff for polishing dirt with gold.
with this process if there is silver in the solution it falls to the bottom as scums than you use nitric to get the silver
Would this be a corrected summary of this process

Click to expand...

When processing this type of material, it's best that you make a decision up front on the recovery of silver, or simply allowing it to remain in the waste, for future recovery. The reason is that the silver is generally very finely divided. The HCl treatment is done hot, so silver is converted to silver chloride, which is not recovered by nitric at a later stage of processing.

So then, armed with this idea, a decision should be made up front on what your recovery purpose should be. If you do a nitric digest instead of an HCl wash (after screening), the resulting solution most likely will not filter well, if at all. When I'd process wastes from a silversmith's bench, one that did only a small amount of work in gold, I'd do the nitric process instead. Once I had recovered the silver (I allowed the solution to settle, then I'd siphon instead of try to filter), I would then incinerate the material, then revert back to the HCl hot wash. Without that, filtering the resulting gold bearing solution that would follow would be extremely difficult.

I hope this makes sense. If I leave you confused, please ask for clarification.

Harold

Hi Harold
That help a lot because I was a bit confused
Thanks

I was also wondering about the acid after all the valuable metals were cemented.

What do do with this acid ,can it be used for something or is it neutralized and thrown away and what is it called
Thanks

PreciousMexpert said:

I was also wondering about the acid after all the valuable metals were cemented.

What do do with this acid ,can it be used for something or is it neutralized and thrown away and what is it called
Thanks

Click to expand...

I can't speak on the subject of reclaiming. In my case, when values had been extracted, heavy metals were removed from solution and the solution discarded.

Lazersteve had done considerable research on the subject of recycling solutions. Perhaps he can provide guidance.

Harold

I am thinking maybe the waste acids can be used for making colorful beads.
For example copper nitrate would be good for that and maybe even iron nitrate, I am not exactly sure if the term iron nitrate is correct

I know that if there is tin in the solution you add sulfuric acid and it falls to the bottom
I think lead also falls to the bottom but I am not sure about that
Thanks

golddie said:

I am thinking maybe the waste acids can be used for making colorful beads.
For example copper nitrate would be good for that and maybe even iron nitrate, I am not exactly sure if the term iron nitrate is correct

Click to expand...

Copper nitrate readily absorbs water from the air and would not be good for jewelry beads. Copper Sulfate will form nice crystals that keep their shape in the air.

Copper nitrate can be recycled by several methods posted on the forum. Use the search tool and put in Cu(NO3)2 by author lazersteve or search on copper nitrate. It has many uses from making nitric acid to dissolving sterling silver electrolytically.

Steve

Thanks guys for the vote of confidence and for the replies to PreciousMexpert's questions.

For some reason Internet Explorer would not let me log in to the forum since Friday morning. The home page would come up but it would error whenever I tried to enter the site. I tried on 3 different computers. Thought maybe I got banned for some reason...lol.

I would like to add that I was able to recover about .95 grams of silver from my trial batch just from collecting the silver chloride that formed by using ice to dilute my warm solutions after siphoning between AR batches and evaporations. Possibly because I might not have boiled long enough with my HCL before going to AR.

Mike

I know that if there is tin in the solution you add sulfuric acid and it falls to the bottom
I think lead also falls to the bottom but I am not sure about that
Thanks

Click to expand...

Lead does fall to the bottom as well in AR

Hi Mike
You add the ice to dilute and the AR and the silver stays in the solution and gold falls.
Do you use copper to cement the silver that remains in that solution
Thanks

I would like to add that I was able to recover about .95 grams of silver from my trial batch just from collecting the silver chloride that formed by using ice to dilute my warm solutions after siphoning between AR batches and evaporations. Possibly because I might not have boiled long enough with my HCL before going to AR.

Click to expand...