Best way to process this

[Geo]

It's ok spaceships, most everything a person from "across the pond" says here gets a chuckle. :lol:

 

[Anonymous]

Haha good answer mate. 8)

 

[joubjonn]

Don't forget to tell us the yield on that. Should be pretty good I would guess.

 

[necromancer]

Thanks,

Any thoughts on a source of nitric? I'm near philadephia.

I do have some very old nitric, around 16 oz. It was lab grade but has been sitting around a long time.

What is considered dilute and how to go about it?

Thanks

if the bottle is closed tight you should be ok. put a drop on a piece of copper, if there is a good reaction your nitric is good
(do this outdoors) away from people & pets

dilute nitric.....
ad nitric acid @ 70% to equal amount of water = 35% nitric acid. (50/50 nitric) always ad acid, never ad water to your acids

 

[pgms4me]

I have some similiar housings like that. They are RF amplifier housings,except mine are silver plated. I have no idea what to do with them. they are about the same size 8" x 12" x 4" The base metal is close to 6061 aluminum. Any ideas??

 

[necromancer]

i see a number on the photo in the OP
it's 9407-1 what other info is there that i can look up?

 

[goldscraphobby]

That number was stamped on by the machine shop. No other markings- I would have to double check what class thickness the plating was by I think it was a minimum 150 to 300 max micoinches and no brighteners

I'll take a small one and throw it into the dilute nitric, let it sit and see what happens.

 

[nickvc]

If this was mine I know exactly how I'd strip it but that route isn't one I wish to promote.
As hydrochloric is cheap and easy to obtain why not expose the core and dissolve the aluminium leaving the foils for a final refining where your nitric will be useful, aluminium will react very violently with the acid so I'd be tempted to start with the items in water and slowly add the acid, I'd start with a small item first to be able to control the reaction and gain an understanding of how much acid to add at each addition and also to see if its worth the effort. Please note this reaction will produce volumes of fumes so a good hood or doing it outside and with a fan or wind behind you is a must.

 

[pgms4me]

Those look almost exactly like my silverplated ones. They weigh 6-10 pounds each. That is a lot of aluminum to dissolve. Sodium hydroxide would also dissolve the aluminum. Might even be more cost effective?

 

[goldsilverpro]

That number was stamped on by the machine shop. No other markings- I would have to double check what class thickness the plating was by I think it was a minimum 150 to 300 max micoinches and no brighteners

As long as you're going to dream, you may as well dream big. How on earth did you come up with those thickness numbers? I would be very surprised if they even ran 50 micro". Unless you can post an official reference saying the gold on that exact part is 150-300 micro" thick, I'll never believe it. For your sake, though, I hope you're right, but the odds are against it. There's only one way to find out - stop talking about it and start processing. A couple of years ago, I visited a place that had several gaylords full of these exact same parts of various sizes, both the gold plated and the silver plated variety. Some had covers on them. Most were an aluminum base and some were of a copper alloy base. None of the gold ones even got close to those thicknesses you speak of. When you own the material, it's human nature to believe the highest numbers you can find anywhere and jack up the value in your mind. I've done it myself, more than once.

I would definitely use the sulfuric stripper but I would cut up the part in about 3"x4" pieces. The sulfuric stripper works fine on aluminum without attacking it, assuming you run it properly and don't use too much current and get the solution too hot (not over 110F). To do this, I would suggest not exceeding 5A/gallon. The stripper works fine with low current. It's just a little slower. You never need lead cathodes in the sulfuric stripper. Just use 2, 1/8" pieces of steel sheet as cathodes wired together, one on each side of the anode. I would make the cathodes about twice as big as the anode.

With any electrolytic system, the current is not applied evenly on the part. Protruding areas get the most current and the cavities get the least. The cavities will likely strip last. However, these were plated electrolytically and, therefore, the gold is probably thinner in all those cavities than on the outer surfaces, unless they used a conforming auxiliary anode in each cavity, which is very unlikely.

There is most probably a nickel layer between the Al and the Au. They wouldn't use copper because of the Au/Cu migration problem, although Cu could be used between the Al and Ni. I've never seen Au plated directly on Al. The no brightener gold sounds reasonable. When brighteners are used (usually small amounts of Co or Ni), the gold purity is lowered (usually to about 99.7%) and this affects things like electrical conductivity. With no brighteners, the gold would be 99.99% pure. It would also be softer but, since this isn't a wear area, like fingers or pins, that wouldn't cause any problems.

 

[goldscraphobby]

I have to build a cell and setup a place for it. In the meantime I am going to put a smaller housing into dilute nitric and see what happens.
These are scrap housings from a "weather" satellite. I do not have the drawing specs they were either a Class 4 or 6. You are probably right and these will be the Class 4 and the smaller are the 6.

We'll see.

 

[pgms4me]

. A couple of years ago, I visited a place that had several gaylords full of these exact same parts of various sizes, both the gold plated and the silver plated variety.

Goldsilverpro: Are the silver plated ones worth processing? and if so,what would be the best way?

 

[etack]

. A couple of years ago, I visited a place that had several gaylords full of these exact same parts of various sizes, both the gold plated and the silver plated variety.

Goldsilverpro: Are the silver plated ones worth processing? and if so,what would be the best way?

If they are silver over Al and you have quite a few of them then they would be easy to run. Just use nitric and be done with it. The Ag over Al wave guides came up a few years ago and Lou made a comment about the economic viability of it.

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=37&t=14153&hilit=silver+waveguides

Eric

 

[pgms4me]

Thanks for the reply Eric and the topic post too! Donn

 

[goldsilverpro]

I agree with etack. Nitric.

 

[goldscraphobby]

It worked!!
I had a small amount of old nitric and put one of the small housings in it in a small container and sat it on a shelf a few months back and forgot about it. I recently took it out and at first I didn't think it did anything but I looked closer and all the gold was mostly detached but still in the same form. Doesn't look like it did much to the housing.
So I peeled it off and that is what I got.
I just found some nitric and going to soak one of the big ones. The nitric is 70% so is a 1:1 with distilled water the best? Also is there any form of plastic that should not be used? I would be looking for something 4"x 12"x 14" with a lid.

 

[g_axelsson]

I just found some nitric and going to soak one of the big ones. The nitric is 70% so is a 1:1 with distilled water the best?

Great result!

You have the pieces so you tell us.

Break off some smaller pieces from a larger one and put into a series of different concentrations, put some loose lid on and check back regularly to see which one works and how fast.
I should suspect that the fastest one is 1:1 concentration but 1:10 would also work, just a lot slower. Then the question becomes how fast do you need to work and how much do you want to spend on acid.

To avoid dissolving some of the gold you should avoid water with chloride in it. Chlorides can be removed by adding silver nitrate solution until there is no white cloudy precipitation, then it is chloride free.

Let us know how it went.

Göran

 

[bswartzwelder]

It has been said on the forum that you don't need distilled water for much of what we do. For final cleaning of gold it would be a good idea. Having said that, distilled water is well under a dollar a gallon at WalMart. Way cheaper than most anything else around. When the season rolls around, I buy 10 or more gallons of distilled water at the start on my recovery/refining season. It has other uses around the house and doesn't go bad.

 

[g_axelsson]

Not everyone has Walmart around the corner. I'm lucky enough to have chloride free tap water. Not a hint of cloudiness when I dilute silver nitrate.

Göran

 

[snail]

Don't foget water from dehumidifiers and air conditioner condensate, both are free sources of distilled water.
Dale