Jewelers Polishing Wheel Waste Experiment

[kadriver]

The solids are running clear and all the gold bearing solution is in the big flask filtered twice

 

[kadriver]

Transferred the solution to a clean 2 liter beaker

 

[kadriver]

To save time I added sulfamic acid to kill any excess nitric acid - Time is of the essence, my friend wants to see his metal TONIGHT!

 

[kadriver]

I then began to add Sodium MetaBisulfite to precipitate the gold

 

[kadriver]

After allowing it to settle a few minutes I began to filter out the gold powder

 

[kadriver]

Filtering complete, I transferred the filter with the gold in it to a 400ml beaker and added about 100ml hydrochloric acid

 

[kadriver]

Then I began adding small amounts of concentrated nitric acid - I only had to add about 6ml to dissolve all the gold - added low heat too.

 

[kadriver]

In a short time the gold was all dissolved so I added a little more sulfuric acid to precipitate any lead that made it this far.

 

[kadriver]

I added a couple ice cubes to cool the solution before filtering

The filtered solution was clear and completely free of contamination

 

[kadriver]

The clean gold solution was transferred to a beaker and then SMB was added to precipitate the gold again

 

[kadriver]

The gold came down quickly and cleanly so I threw it into a filter and then into a melt dish, filter and all, and covered with about a table spoon of borax.

I then poured the pure gold into cold water, dried and weighed it.

This was much fun as it was all new to me and it came out way better than I expected.

Of course my friend was very happy to see his metal this evening.

kadriver

 

[butcher]

kadriver,
I always enjoy reading and seeing your posts and videos, you do a very good job at helping others to see what is going on with a few pictures.
I think you did a good job in this experiment, and with what you're learning from Harold you will only improve on the process.

Great job and thank you for sharing.

 

[Harold_V]

I said I was astonished at the amount of gold I got from the small sample.

And now you understand why I have insisted that in order for the home refiner to be (really) successful, he/she should have jewelers as customers. They provide waste materials that are high in content, and also become a source where one can sell their recovered gold for spot price.

Processing wastes from a jeweler's bench kept me so busy I refused to process escrap. I couldn't justify the time spent doing so.

A comment.
If you circumvent the preliminary HCl wash, you're going to encounter solutions that are difficult, if not impossible, to filter. Beyond that, because the vast majority of contaminants are removed in the wash and rinse, before dissolving values, the quality of gold that comes from the process is often as good as that which comes from a second refining.

I NEVER used a Buchner for filtering gold chloride. Two reasons. One of them was that I used an aspirater to create vacuum, and on more than one occasion it added water to the solution when filtering other substances. I also experienced the Buchner picking up the filtrate, running it to waste. Both were unusual circumstances, but they occurred on more than one occasion. I was not willing to experience the risks.

Harold

 

[kadriver]

Thank you for your comments.

I am not a big fan of e-scrap either.

My friend gave me another 400 gram batch of polishing sweeps and I have already started on that.

He also gave me a bag of filings to process.

This too will be my first try at this type of material.

I'll be sure to review Hoke's processes for filings - he said it does have just a little platinum.

Of course I'll review any posts here on the forum for jewelers filings.

kadriver

 

[kadriver]

I found Harold's PDF file on how to process filings.

I was able to save it to my iPad so I can use it as a guide when I start working on these filings.

http://goldrefiningforum.com/phpBB3/download/file.php?id=18196

Thank you Harold!

kadriver

 

[4metals]

The moderators would like to thank all of the members that contributed to the original thread upon which this thread was based, as well as those that asked questions showing what was missing. Because of the extra length and interest in this thread we have created the above consolidated version making for an easier read. We encourage all members to read, comment, and ask questions in the original thread, Jewelers Polishing Wheel Waste Experiment.

The Library threads should not be considered to constitute a complete education. Instead, they're more like reading a single book on the subject of recovery and refining. There is so much more information on the forum, and it is impossible to include it all in these condensed threads. Members are strongly encouraged to read the rest of the forum to round out their education.

For those who prefer a printed copy, a pdf file of this thread is provided below.