Dissolving rust to free trapped gold

[KevinInColorado]

OK guys, easy question...what's the cheapest way to dissolve rust away? This pic is a pan full of rusted junk I've collected while prospecting. As you can see the rust has had time to bind up lots of other stuff. It's going to be too cold to prospect this week so I guess it's time to dissolve the rust to free any gold. Some of this is from a really rich mountain claim but I still want to be smart about this...no point spending $10 to get $5 of gold now is there!?

 

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[Jonsered]

As far as it causing gold plating--don't know. I think maybe that your Au has to be in solution. Someone onTn should chime in.

Absolutely right. Has to be a gold anode and gold solution. Did this for years in the medical industry.

Edit: Let me rephrase that before I get jumped. It is POSSIBLE that an extremely thin layer of gold MIGHT adhere to your anode. Very slight possibility and a VERY thin lightly stuck layer.

 

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[golden sluice]

Take it to a paint shop, ask if they could glass bead blast the rust off em, then just pan out the debris. Hmmm, im going to harbor freight to see how much their glass bead machines are.

 

[golden sluice]

Btw that hot sauce thing wont work, its just a vinegar base... hotsauce is what we used to clean brass on the boat in the navy lol. I think glass beads will work best.

 

[G1sammons]

Sometimes you have the most fun where ya never even think to look! Truly hope ya find a monster nugget in that bucket...

 

[loco oro]

ive restored an old iron stove that was rusted horribly and what i did was place the pieces in a wood fire allow to good an hot 10 mins 15 mins aand then pulled from fire and wire wheeled them back to a shine ,all the rust flaked right off no problem,do this over a container and crush and pan.

 

[KevinInColorado]

Sometimes you have the most fun where ya never even think to look! Truly hope ya find a monster nugget in that bucket...

Or at least one little flake!

ive restored an old iron stove that was rusted horribly and what i did was place the pieces in a wood fire allow to good an hot 10 mins 15 mins aand then pulled from fire and wire wheeled them back to a shine ,all the rust flaked right off no problem,do this over a container and crush and pan.

Don't have one of those and trying to spend less to remove the rust than the gold values I'm likely to find so no new power tools allowed on this project (darn!). Also one of the items is a piece of drive chain rusted totally solid...too complex a shape to process mechanically. That's part of the reason for my focus on chemical means of destruction!

...now if only it would warm up enough for my acid solution to melt and react brrrr!

 

[LP13]

Or at least one little flake!


Don't have one of those and trying to spend less to remove the rust than the gold values I'm likely to find so no new power tools allowed on this project (darn!). Also one of the items is a piece of drive chain rusted totally solid...too complex a shape to process mechanically. That's part of the reason for my focus on chemical means of destruction!

...now if only it would warm up enough for my acid solution to melt and react brrrr!

Take a little salt (good old sodium chloride) or no-salt (salt substitute, potassium chloride) and add to the solution. It will melt the ice and add some chlorine to what you are up to, which won't hurt a bit. Won't take much to get rid of the ice. Won't react with the acid and blow up on you either ...

 

[KevinInColorado]

Great idea LP13.

Edit: I did that on Friday after work and added a bit more salt today (Monday) as there was still quite a bit of ice crystals in the pan. The good news is that it's working! Both the drive chain and a large nut (yes, I know...like me!) are now rust and accretion free! I'm going to leave it another day and then start on processing the material I've freed from the rust.

 

[KevinInColorado]

Well, the spa filter cleaner had enough sulphuric acid to totally do the job. I panned out the resulting 1/2 cup of sandy, fine gravel and did find one small flake. No big score but confirms the process and the idea that gold can get bound up in rust as it grows on a piece of metal deep in the creek bed. Thanks for all the ideas and help everyone!

Edit: on further review I found another, very small flake

 

[mirkaba]

In the early 70's I recovered some classifier screen from an old stamp mill. It was heavily rusted and the gold particals were visible in the rust. I used a dilute mixture of nitric acid to dissolve the rust and screen. I was suprised at the amount of gold I recovered.

 

[KevinInColorado]

In the early 70's I recovered some classifier screen from an old stamp mill. It was heavily rusted and the gold particals were visible in the rust. I used a dilute mixture of nitric acid to dissolve the rust and screen. I was suprised at the amount of gold I recovered.

cool story! Jealous