# Gold on Nickle stainless steel alloy



## yvonbug (Jun 11, 2018)

Ok, I've started a new thread, because I've a different metal to deal with. If I try to slowly dissolve the gold off the nickle/stainless steel body, and some of the metal other than the gold goes into solution with the gold, could I drop it out before I drop the gold? And if so, what would I use? If this is a bad situation,would it be better to try the electroplating method? And what would I use for that? Never have done that before, (but it sounds interesting, and I want to try it.) I think this could be fun. Here's a picture of the part.
And Thanks again to Geo for identifying the metal!


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## Lino1406 (Jun 11, 2018)

Did you try A/P? Should dissolve nickel


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## Geo (Jun 11, 2018)

Actually, AP is very poor at dissolving nickel. That's why foils recovered through the AP process is so very contaminated. I'm sure it dissolves some of the nickel but certainly not all of it.


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## yvonbug (Jun 12, 2018)

Or if I dropped the gold out, using sodium sulfite, would that leave the other metals behind in solution? It'd probably be contaminated gold, but then I could refine it again?


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## Geo (Jun 12, 2018)

Yes. Absolutely.


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## Palladium (Jun 12, 2018)

You said drop, but from what? ar nitric ap ???


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## FrugalRefiner (Jun 12, 2018)

Palladium asked an excellent question. In the previous thread, Rather thick gold plating on aluminum, Geo mentioned using "concentrated nitric acid and adding HCl by the drop at a time". I believe GSP introduced this method to the forum, and it has come to be known as "reverse AR". Is that what you're going to try, or something else?

Dave


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## yvonbug (Jun 12, 2018)

Hmmm, sometimes I am so slow.....Yes, that's what I thought I'd try. ??


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## Palladium (Jun 12, 2018)

I'm kind of lost here. 
Thought you would try implies you haven't done it that way yet. What type of solution are we talking about?


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## anachronism (Jun 13, 2018)

If you're going to try reverse AR Then I'd recommend some in depth research first. 

It's very prone to a runaway reaction if you get your HCl amount too high. That's a reaction that gives off so much heat that it becomes self sustaining and increases as the temperature gets higher. If it gets away from you it can get messy and dangerous very fast. 

Also you need to work out how to get the gold from the gold chloride in a solution which effectively has an enormous amount of excess Nitric. 

I haven't had the need to do this very much at all. My experiments with it have been very small scale.


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## g_axelsson (Jun 13, 2018)

When dealing with massive pieces of base metal with a tiny amount of gold on the surface it really doesn't pay off to dissolve the base metal. It is costly and creates a lot of waste.

In this case the sulfuric cell or cyanide leaching is the only reasonable way to go. Then you can sell the metal as scrap when the gold is gone.
Sulfuric acid is dangerous, but cyanide is lethal, so for me the choice was simple.

First time I tested the sulfuric acid cell it was like magic, ran a couple of kilos of anything from heavy connector shells to gold plated stainless spoons. The thing that limited how long I ran the cell was the amount of water absorbed, but that was totally my fault and it was a small test setup just to get the feeling.

Göran


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## yvonbug (Jun 13, 2018)

I did mention that I'd like to try the reverse electroplating method also. Learning new stuff is fun to me. I watched a youtube video on this, but the guy used real strong sulfuric acid. I've got some battery acid that I just bought, so it's fresh. Anyways, the process looked real easy, and I thought it would be better than anything else. Like less unfortunate mistakes to be made. But I was also considering the (reverse ar) method. But now I'm leaning towards the electroplating method, cuz it sounds a little safer. (is that a word? Safer?) I've got a battery charger, a casserole dish, lead to make the cathode? with, and I can get some copper mesh from the craft store to make a basket-anode. uh, what do you think?


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## FrugalRefiner (Jun 13, 2018)

Your fresh battery acid will dissolve a lot of base metals, including your copper mesh anode basket. Concentrated sulfuric acid is needed. Diluted acid, like your battery acid, is very different. You need to study in depth, not just watch a youtube video. I don't mean to be harsh, but the sulfuric stripping cell has been discussed in depth. Study before you try it.

Dave


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## g_axelsson (Jun 14, 2018)

Yeah, just as Dave stated, you need concentrated (>90%) sulfuric acid. As it will absorb moisture over time it is always best to start with 96%.

The theory (as I understand it) behind the reverse cell is that concentrated sulfuric acid actually oxidizes the surface so it is covered by a protective layer. That way the only thing that is affected is the noble metals that are dissolved.
Once the concentration drops below a certain point the additional water makes it possible to dissolve the metal instead and it is a quite distinct point where the cell starts to work bad.
When the acid can go after the base metals it will do it and the precious metals will be mostly untouched.

Göran


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## Owltech (Jun 14, 2018)

Iodine/Iodide works great on this type of scrap


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## anachronism (Jun 14, 2018)

Owltech said:


> Iodine/Iodide works great on this type of scrap



I agree with the approach in terms of leaching. People do need to find a surface leach process rather than dissolving loads of base metals on this kind of gear. I don't advocate the sulphuric cell personally. It's vile and remarkably unsafe when used with a jam jar/home material setup. 

Frankly the eco goldex stuff appears better overall.


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## yvonbug (Jun 15, 2018)

I didn't think anyone was being harsh, just trying to drive a point home to me. Yes, I'm reading my Ammens and Hoke. Ammens kinda lost me this time. Going to look up leaching too. I'm getting old enough to want to take short cuts. Which isn't safe or good for my brain. Wanted you guys to tell me everything I had to do, and that's not right either. So, with that said, Everything you all have said already, Thanks for helping!
Leaching sounds interesting, also. So I'm off to study up on these last 2 methods. I'm never too old to learn new stuff!......


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## yvonbug (Jul 4, 2018)

Well, I've been checking out the reverse electroplating method. While I've been waiting for my order of 93% sulfuric acid to arrive, I tried out a small (just 2 parts) batch using the battery acid I had bought. And found out it does just what Goran said. It worked a little bit but then started coating the item with copper from the basket. But, aside from that, the battery charger I was using kept cutting out, like it was on a trickle charge. I had it set on 2 amps and 6 volts, then 2 amps and 12 volts. Both times it started cutting out and then it finally just quit. On this particular charger the next amp setting was 15 and I didn't want to go there. So, I went and bought me a little charger today that is only 4 amps. with 6/12 volts settings. Anyways, this charger is a High Frequency charger/maintainer. Is this going to ....not work with what I'm trying to do? It's a Viking 4 amp fully automatic microprocessor controlled battery charger/maintainer.


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## g_axelsson (Jul 4, 2018)

When it comes to electrochemistry, a smart battery charger is not a good choice. It finds out that it isn't a battery it tries to charge and treats it as either a fully drained battery or a faulty battery. Old time battery chargers with a big transformer, rectifier... and that's it, is a lot better. It will deliver the power you want until it blows a fuse.

Best thing to use is a lab power unit. With both voltage and maximum amperage settings. Then you can fine-tune the reaction. It works for smaller units, for a larger setup there are specially made power supplies for electrolytic baths.

Göran


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## yvonbug (Jul 6, 2018)

OK, Thank-you. I'm going to return the little charger and ask around for an old one. One of our friends has got to have one sitting around in their garage or back shed. I've got my concentrated sulfuric acid and I don't want to mess with it until I've got everything else set up right. One other thing, does it make any difference if I use a thin sheet of copper with a zillion holes punched in it, or should I use copper mesh? :?


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## g_axelsson (Jul 6, 2018)

Anything goes as long as it doesn't form a screen between the electrodes. The current have to reach the object to be deplated. There also have to be an electrical path from the copper to the object being deplated.

A copper mesh is just easy to form and doesn't create any pockets so it is easy to drain when removed from the cell.

It looks like there is several holes in your parts, I would form hooks out of copper wires and have another one going straight over the vessel for sulfuric acid and just hang it from that, that way you can prepare the next one while one or more are deplating.

Check this video and you will see what I'm trying to explain.
https://www.youtube.com/watch?v=5gCsty84VvA

I have more references collected on this page : http://goldrefiningwiki.com/mediawiki/index.php/Reverse_plating_cell

Göran


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## nickvc (Jul 6, 2018)

Gorans idea as usual is a good one as if the pieces do have holes the plating will be thickest there, I’m sure someone can explain why, so having the current running from them should help to deplate quicker and more completely.


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## bigpagoda (Jul 11, 2018)

Great video. Is that an aluminum heatsink you are using to absorb the heat out of the hot beaker before you add the ice? I have several large ones I use for welding thin material I'll have to give that a try.
What were the gaskets from?
Paul


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## yvonbug (Jul 12, 2018)

I got too excited watching the video, that I had to pause it at 9:30 cuz I just had to say: Wow! Cuz I had already run a few parts and it went so fast! Why hadn't I done this years ago?! I did put my parts on a copper wire instead of a basket, so I could just hang it on the side and connect the charger to it. But I really like the idea of hanging them off a copper pipe! I've already learned, from the video about the foam being flammable. That surprised me. And I notice that as you go on using the cell, that it works faster and faster. I guess that's cuz of the heat it's generating. Anyways,....Whoopeee! I love this stuff! (and thank-you Goran, for the help and the references!) Did I already ask you if we were related? Do you know any Lilja's? Or Thorbjornson's? My last name is Torburn. It's been Americanized. Just wondering.


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## g_axelsson (Jul 12, 2018)

Hehe, no I don't think you asked me that before.

The part of my family that I have knowledge of comes from northern Sweden, there were a few persons emigrating a hundred years ago and my dad keeps in contact with a cousin of him. I don't know what their family name is though.
Torbjörn is a common name in Sweden and the sons from someone called Torbjörn would be Torbjörnsson in Swedish. I know of one relative called Torbjörn but that's recent and both his sons live in Sweden. Lilja is also not uncommon but I have only met people living in Sweden and I don't keep up with any of them today.

We are around 10 million people here and it's a big country... but you never know until you asked.  

Göran


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## yvonbug (Jul 12, 2018)

This isn't on thread. But I was wondering, now, what time it was where you are at? It's 1:00 am here in California.


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## g_axelsson (Jul 12, 2018)

I'm 9 hours ahead of you.  

1.15 PM right now.

Göran


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## yvonbug (Jul 23, 2018)

Well, I'm almost done using my reverse plating cell. Or sulfuric cell. Whatever we want to call it. I really do wish I had tried this years ago. Everything worked just fine. Now I'm waiting for the bath to settle so I can decant the sulfuric off. The sulfuric is re-usable? I've got to get some nice glass jugs to store it in. I've already filtered my rinse water. Lots of "Black gold" in that. But, still having the water from that, maybe I should use that to dilute the remaining sulfuric acid that has the black stuff in it. I didn't rinse one of my filter papers very well and it turned all mushy. I've set that aside to deal with later. Anyways, I'm really happy with how this method worked. Filtering always takes up a lot of space and time. But that's ok, cuz the end result is worth it.  I'll take some pics of my little set-up and post them, And then I'll take pics of the little button I'm going to get out of this. And thanks again to everyone for helping me out! Yvonne


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## nickvc (Jul 23, 2018)

The sulphuric is reusable but it needs to be concentrated to work efficiently so store it in air tight containers because it’s so water hungry it will draw it from the air around.


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## yvonbug (Jul 26, 2018)

Are there storage containers that are easily accessible that are good for storing sulfuric acid? Like in the 500ml range? By that I mean can they be found in your local hardware store, or do I have to order some?


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