Equipment needed for refining placer gold

[thesilverfox111]

What would be the necessary equipment to be able to refine placer gold at a home work shop?

The placer gold is mostly gold with a bit of silver. Anywhere from 85% gold and 15% silver to 93% gold and 7% silver. There is the odd very small percentage of other metals but the two metals I want to separate and recover are the silver and the gold.

The placer gold is fines and nuggets with some of the pieces having small amounts of quartz attached.

I would be refining anywhere from 1 to 20 ounces at a time.
I have seen the microwave kiln smelting kits on line but I would like to do it safer and not with a microwave if I can get all the supplies without killing the bank account.

I am in BC Canada so if anyone can suggest a supplier for the needed equipment that would be also be appreciated.

 

[nickvc]

With the lower grade placer you may need to inquart the metal and then dissolve the base and silver using nitric acid and then you can dissolve the gold using AR, the silver can be recovered by cementation using copper, the gold solution will need filtering and precipitating, if the gold has only 7% silver you can dissolve it directly with AR using heat, filter to remove the silver chloride, rinse well to remove all the gold solution which you can then precipitate, the silver chloride can be converted using many methods all of which are fully outlined on the forum
All this can be done with fairly cheap equipment but will need doing outside, the other choice is a fume hood and extraction to pull the fumes away from you.
Be aware all these processes produce toxic fumes make sure to read all the safety threads to protect yourself, personally I would prefer a fume hood, extraction and a scrubber system but hat gets a little more expensive but if your handy not too much.

 

[FrugalRefiner]

You probably already know this, but you can probably sell anything that qualifies as a nugget at a premium. Even fine placer gold can be sold at right around spot, which is a premium considering it's not pure.

If you choose to refine it, you can get by with a couple of beakers and some disposable pipettes. A hot plate and a pyroceram dish will allow you to speed the process up by heating.

You'll need melting dishes and a torch to melt the refined gold. You can get by just melting buttons for small amounts, but for larger amounts you'll need a mold and some kind of tongs to hold the dish when pouring.

As you do more work, you'll probably find other things that might make things easier, but for first attempts, you really don't need a whole lot of equipment.

Dave

 

[Irons]

A Mercury Retort would be the first item on my list.

 

[4metals]

You didn't mention how the material was collected and you may not know. Because you likely are not sure, Irons suggestion of a retort is a wise first step.

to build a cheap one to get started follow the instructions of this PDF;

https://practicalaction.org/docs/technical_information_service/mercury_retort.pdf

mercury isn't something you want to mess with.

 

[thesilverfox111]

With the lower grade placer you may need to inquart the metal and then dissolve the base and silver using nitric acid and then you can dissolve the gold using AR, the silver can be recovered by cementation using copper, the gold solution will need filtering and precipitating, if the gold has only 7% silver you can dissolve it directly with AR using heat, filter to remove the silver chloride, rinse well to remove all the gold solution which you can then precipitate, the silver chloride can be converted using many methods all of which are fully outlined on the forum
All this can be done with fairly cheap equipment but will need doing outside, the other choice is a fume hood and extraction to pull the fumes away from you.
Be aware all these processes produce toxic fumes make sure to read all the safety threads to protect yourself, personally I would prefer a fume hood, extraction and a scrubber system but hat gets a little more expensive but if your handy not too much.

Thank you Nickvc I will be checking out the tutorial section and youtube vids etc to see if I can get a good idea of how it's done.

You probably already know this, but you can probably sell anything that qualifies as a nugget at a premium. Even fine placer gold can be sold at right around spot, which is a premium considering it's not pure.

If you choose to refine it, you can get by with a couple of beakers and some disposable pipettes. A hot plate and a pyroceram dish will allow you to speed the process up by heating.

You'll need melting dishes and a torch to melt the refined gold. You can get by just melting buttons for small amounts, but for larger amounts you'll need a mold and some kind of tongs to hold the dish when pouring.

As you do more work, you'll probably find other things that might make things easier, but for first attempts, you really don't need a whole lot of equipment.

Dave

Thank you Dave. Yes I realize the nuggets do sell on line for a premium. I follow some of those online sales to see what nuggets are selling for. Sometimes they go for around spot and sometimes a bit under and sometimes more than spot if they are nice big ones. The thing with the online sales though is there is listing fees, selling fees, paypal fees, c/c fees, etc. so the bottom dollar received is a fair bit lower than the actual sold price. But yes, I am saving the large nuggets to sell to collectors. The smaller nuggets in the under 1/2 gram to around a gram size don't always get too much of a premium I am seeing with collectors. So any small ones under a gram I will be trying to refine with the other finer gold.
It sounds encouraging that I won't need too much equipment to get started learning how to refine the placer gold. It will be something I can learn and improve on over the winter months when mining is over for the season.

You didn't mention how the material was collected and you may not know. Because you likely are not sure, Irons suggestion of a retort is a wise first step.

to build a cheap one to get started follow the instructions of this PDF;

https://practicalaction.org/docs/technical_information_service/mercury_retort.pdf

mercury isn't something you want to mess with.

Thank you 4metals. I've read some nasty stuff about Mercury so I would like to try to stay away from it if possible. Or are the other acids etc. just as nasty as the Mercury? I plan on doing everything very safely, with the proper ventilation and air quality control, etc.
I am a prospector/miner. I have a permitted placer mining claim. I am doing exploration on my claim this year and probably the next few years. So no heavy production mining yet but I am still getting my own placer gold with my exploration and I have some friends who mine who I will be buying some of their placer gold from. We use dozers, excavators, trommel wash plants, and sluices. And the gold is extracted from the concentrates without any Mercury or other chemicals. After all the visible gold is removed we are left with the black sands super concentrates.

 

[nickvc]

For safety's sake I'd suggest an assay or two on the materials to be treated, the use of mercury is not legal now but you may encounter some from older mining or from nature itself.
If the assay charges are too high I can suggest someone over here who will be quick and cheap, you just have to get the samples to them, they won't need much probably maybe 1/2-1 gram per sample, let me know if you need their details I'm happy to pass them on.

 

[thesilverfox111]

For safety's sake I'd suggest an assay or two on the materials to be treated, the use of mercury is not legal now but you may encounter some from older mining or from nature itself.
If the assay charges are too high I can suggest someone over here who will be quick and cheap, you just have to get the samples to them, they won't need much probably maybe 1/2-1 gram per sample, let me know if you need their details I'm happy to pass them on.

Hi nickvc, yes my neighbor mining the claim next to me just had an assay done on their last batch of gold they sold. It was 89% Au and 9% Ag. I am also getting an assay on my gold from a different assayer too to confirm my neighbors results and plan on doing the other miners gold I will be buying.

Our land we are mining is virgin ground. It hasn't ever been mined before so there is no mercury on the gold. I will confirm whether the other miners gold from the other area is from virgin ground or not.

Thank you very much for the offer to help with an assayer. I will send you a PM.

 

[Platdigger]

Virgin ground does not necessarily mean there is no mercury.
I am not saying that yours does, just saying.

 

[nickvc]

Paul I'm happy to post the information openly the only problem you have is getting the samples to them but that can be arranged as they don't need too much.
Guardian Laboratories (Midlands) Limited.
+44 121 359 8233 Speak to Austin and explain what you need and he will be vey helpful, if I remember correctly it's £10 per element for Au and Ag, it's a fire assay and will be done in 24 hours of them getting the sample.
I know other members have used them so they are worth talking to.

 

[thesilverfox111]

Paul I'm happy to post the information openly the only problem you have is getting the samples to them but that can be arranged as they don't need too much.
Guardian Laboratories (Midlands) Limited.
+44 121 359 8233 Speak to Austin and explain what you need and he will be vey helpful, if I remember correctly it's £10 per element for Au and Ag, it's a fire assay and will be done in 24 hours of them getting the sample.
I know other members have used them so they are worth talking to.

Thank you Nick