How to eat an elephant.

[Toadstool]

Hi all. I have a large (1100 gram) block of what is purported to be a bunch of gold plated pins melted into a brick. What is the best way to even start going about recovering/ refining the gold from this thing? I thought about cutting it up but I don't have any saws.

 

[FrugalRefiner]

The best idea I've heard is to use it to cement other values in your stock pot.

Dave

 

[jimdoc]

Use it as a paperweight.

 

[Toadstool]

The best idea I've heard is to use it to cement other values in your stock pot.

Can you elaborate? I'm still new to this and I've already made way more mistakes than I thought possible.

 

[FrugalRefiner]

Your block of melted gold plated pins has very little gold content. The cost of chemicals to process it will likely outweigh the value of any gold you recover.

We use a stock pot to cement out any trace values in our solutions. You can read about the stock pot in the book in my signature line below. Your bar would serve well as a primarily base metal bar to cement out any trace values that might remain in your solutions. As it is consumed, it will leave the tiny amount of gold, if any, along with any other values that may be cemented.

Dave

 

[Toadstool]

What about for de-NOx purposes? Instead of neutralizing with sulfamic acid, would putting this in a poor man's AR solution use up all of the nitric acid that may remain?

 

[butcher]

The bar came from melted pins, copper is only one of the possible base metals, there can also be some metals that can cause problems if used in your solution like tin...

 

[patnor1011]

I hope you did not pay much for that nice brass bar.

 

[g_axelsson]

What about for de-NOx purposes? Instead of neutralizing with sulfamic acid, would putting this in a poor man's AR solution use up all of the nitric acid that may remain?

That would work but it would also cement any gold in solution.

It could also be used for cementing silver going to a silver cell. The gold would mix with the silver and then report in the slime from the cell.

Göran

 

[4metals]

Do you know for a fact that the bar was made from melted pins? Did you melt it? The reason I ask is because it is one nice looking bar whose coloration infers there is a substantial quantity of gold. If it was made from gold plated copper pins the bar would look like copper.

If someone else made this bar and you bought it (like off ebay) I would suspect there are other metals responsible for the coloration. This may have been alloyed to get the desired color to get more money for the bar. These other metals could cause you more problems. Can you get an XRF of the bar to help figure what else might be in there? I would be surprised if there is any gold in there, I've seen beautiful bars from Africa with no precious metal content sold as gold bars.

Use it as a paperweight.

Sooner or later every refiner ends up with a bar like this and quite frankly use them as paperweights. Fortunately it isn't too large, I have also seen the same ilk of larger bars used as doorstops!

Find out what the other metals are, then we can give you the best options.

 

[upcyclist]

Since it may well contain tin and other undesirable elements, what about throwing it in the bottom of an HCl soak? Just leave it down there when you remove the tin from e-scrap, or drop it in afterwards to deplete the HCl after you've done so?

The HCl would only eat miniscule values if any, correct?

edit: Big Ls to little ones--even if there is no element "L"

 

[4metals]

Depending on what the other metals are, and their concentration, a determination as to what to leach with can be made.

If a bar has 10% tin, for example, that means it has 90% other metals. If those other metals are not soluble in Hydrochloric, then the likelihood of the HCl doing an effective leach is low. This can be overcome by small particle size but that option is out of reach for most. That is why it is so important, in this age of so many varied alloys, to be able to have an element scan of the bar to determine an effective strategy.

 

[rickbb]

Make a small sample of shot or flake from it, then process that to see how much, if any, gold is actually there before going to a lot of trouble.

 

[resabed01]

I thought about cutting it up but I don't have any saws.

A $10 hacksaw from the hardware store will easily cut through your lump of brass.

 

[upcyclist]

A $10 hacksaw from the hardware store will easily cut through your lump of brass.

Indeed! And of course save the swarf/dust from cutting it, at least until you know what it is. In fact, that swarf will dissolve pretty quickly and serve as test material.

Heck, save the swarf, toss in a sprinkle of gold if ya got it, and process it as an acquaintance test.

 

[Anonymous]

Do you know for a fact that the bar was made from melted pins? Did you melt it? The reason I ask is because it is one nice looking bar whose coloration infers there is a substantial quantity of gold. If it was made from gold plated copper pins the bar would look like copper.

I'm with 4metals on this. I also wonder what kind of materials could be used to get that colour because I see a lot of brass and this doesn't look like brass.

 

[Geo]

It doesn't look brushed or polished. If it was pickled, it would be pitted and rough. The dimples are as shiny as the outer surface. Too, it looks like a drop of flux stuck to the top. It it was brushed or polished, that would be gone. We have seen pins that yielded over an ounce of gold per pound before on the forum. Take to a scrapyard that has a hand held XRF and ask them to shoot it for you. It may not be calibrated for gold but it will tell you what the base metals are.

 

[Justincase]

I have been looking at this kind of material and opted for Electroparting to get to a decent concentrate to work with.
Had a number of old solar panel's so just hooked them up with an old battery bank and a current regulator.
It worked great on small test lot's of 100gram's ,took several week's but cost nothing to do ,just salt water and sun light.
So as long as you are not in a rush it is slow and steady.
would like to try a larger test but need to find larger solar panels and a larger bar's to run so would consider making an offer on such material as it is of little use to most people.