using AP method for gold filled

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DylanDownright84 said:
Need some pointers here. My tin solder has been soaking in Hcl for about 18 hours now and there's still nothing going on. Put heat on it and still nothing. The pieces I cut up are still shiny silver looking.
I'm not sure what you expect to happen, but that sounds normal. Stannous solution is colorless. It takes quite a while for all the solder to dissolve, but you don't need it all to dissolve. In fact, you never really want it to all dissolve as your stannous will degrade pretty quickly after it's gone.

Have you tried to use it yet? Dissolve a few of your gold foils in a small amount of HCl and bleach as has been described. Add a drop to a q-tip and add a drop of your stannous.

Dave
 
Then it should work. I was just expecting the solder to turn dark gray like in the videos I watched. I put heat on it again til a light steam started, it did bubble more this time. Turned the heat off and let it sit while I went to a doctors appointment and will check it as soon as I'm back home on some dissolved gold in some Hcl and bleach.
 
I don't want to be a wet blanket, but you may still have a fair amount of base metal there. A wise woman (Hoke) suggested doing small samples when dealing with something new. Take a tiny sample - just a few foils, maybe 1% of your total batch - and dissolve it by your method of choice. Gold in solution is yellow to orange depending on the concentration. Copper, the most prevalent base metal is green to blue. If your solution is mainly yellow you're well on your way. If it's dark green or blue, you may want to put the rest back into the AP for a while longer. Patience.

Dave
 
I make my stannous by adding pieces of solder to the hydrochloric. While it sits, I heat up some water in a one cup coffee maker (dedicated for my refining effort's) and use the hot water to warm my stannous. By the time it reach's enough warmth to notice it isn't cool anymore, I place it in my dropper bottle and use it. The whole process only takes a few minutes.
 
I've slowly been pouring off the used smb solution from the tiny batch of fingers I did last weekend. There's very fine brown particles floating ontop of the solution now. You almost can't even see it unless you're really looking, but it's there. So not to accidentally pour off any gold powder I'm thinking of just boiling it down as it is. I transferred the solution with the gold powder to another coffee pot in order to follow lazersteve's washing process.
 
FrugalRefiner said:
I don't want to be a wet blanket, but you may still have a fair amount of base metal there. A wise woman (Hoke) suggested doing small samples when dealing with something new. Take a tiny sample - just a few foils, maybe 1% of your total batch - and dissolve it by your method of choice. Gold in solution is yellow to orange depending on the concentration. Copper, the most prevalent base metal is green to blue. If your solution is mainly yellow you're well on your way. If it's dark green or blue, you may want to put the rest back into the AP for a while longer. Patience.

Dave

Will do! I washed it quite a few times going from Hcl to water back and forth. Did it enough time that I forgot how many times I did it. I also did 2 incinerations. Everything is in one of my coffee pots now. Suppose a good soak in hot Hcl and another filtering wouldn't hurt, but all I can see is bits of burnt filter and little clumps of gold. I did wash and rinse till the washes came out clear.
 
When we create a solution of "AP", there's a reason we use the peroxide. In reality, what we are creating is a copper(II) chloride (CuCl2) leach.

If you put a clean piece of copper in HCl, seal the container, and leave it for a while, not much happens. Copper does not dissolve in HCl.

If you put an oxidized, corroded, green piece of copper in HCl, the acid will dissolve the copper oxide and the solution will turn green because copper oxide dissolves in HCl. You will have CuCl2 in solution.

If you put a clean piece of copper in HCl and add a bit of hydrogen peroxide, the peroxide will oxidize the surface of the copper, and as it does, the copper oxide will be dissolved by the HCl. You will have CuCl2 in solution.

The interesting part is that a solution of CuCl2 dissolves copper! That's why our "AP" solution works.

When we understand this, we can understand that HCl washes will not wash away undissolved copper. Washes are good! But HCl will not dissolve copper.

Dave
 
That is one of the easiest to understand explanations of how AP works I have seen yet, Dave.
 
Slow down cowboy! Is that the solution you're going to precipitate from? I'm sorry if I'm being harsh, but that's filthy. Your solution, just before you add your precipitant, should be crystal clear. If you precipitate from that solution, your gold will drag down a lot of contaminants.

If your solution is cloudy, just keep filtering. You can pour the same solution through the same filter over and over. As the bigger particles clog up the big pores of the filter paper, it traps smaller and smaller particles. When the solution is crystal clear, you're ready to precipitate.

But I suppose I'm imposing my own standards. I'm just saying, that some additional filtering (and Patience) will result in cleaner gold.

Dave
 
I got ya Dave! This is my 2nd time doing this so I'm still learning. I did filter it again before dropping it, but probably should've filtered it again after reading your post. Losing daylight didn't help either so I went ahead with the process. Once it settles I can decant, filter then dissolve again though, right? I'm really trying to familiarize myself with the process at this point. And this time went alot smoother than last weekend did with the small batch of fingers I did. Not sure why I didn't think to keep filtering it. Noob mistakes lol
 
FrugalRefiner said:
When we create a solution of "AP", there's a reason we use the peroxide. In reality, what we are creating is a copper(II) chloride (CuCl2) leach.

If you put a clean piece of copper in HCl, seal the container, and leave it for a while, not much happens. Copper does not dissolve in HCl.

If you put an oxidized, corroded, green piece of copper in HCl, the acid will dissolve the copper oxide and the solution will turn green because copper oxide dissolves in HCl. You will have CuCl2 in solution.

If you put a clean piece of copper in HCl and add a bit of hydrogen peroxide, the peroxide will oxidize the surface of the copper, and as it does, the copper oxide will be dissolved by the HCl. You will have CuCl2 in solution.

The interesting part is that a solution of CuCl2 dissolves copper! That's why our "AP" solution works.

When we understand this, we can understand that HCl washes will not wash away undissolved copper. Washes are good! But HCl will not dissolve copper.

Dave

I see. Well, if I had still seen copper mixed in with the gold stuff I would've kept it soaking longer, but the last 2 days almost there were no copper to be seen, just tiny little gold bits. I have no doubt I need practice and more experience with everything that this involves, but I was pretty good about allowing the mix to do its thing. I'm sure the more I run this method as well as try new ones the better I'll get at it. Thanks for all your help guys!!!
 
Another visual aid.

Example of a solution that needs filtering.

IMG_0494.JPG

And one that has already been filtered.

Clear solution.jpg


The color will vary at times depending on the contaminant. In the first picture the hydrochloric stayed pretty and clear, even when heated. Upon the first addition of nitric it flashed a dirty green then went to yellow/orange as the powders dissolved further. There is also fluffy pieces floating that settled out in just a few minutes, so it will clearly need some filtering to become clean.
 
Ahhhhhh! Ok! Yeah, mine was definitely filthy then, as Dave stated. Seeing that really helped, Shark! Thanks buddy! The drop I did just before dark is gonna settle till tomorrow afternoon. Then, I'm gonna decant into a filter and start the refining process all over again, this time filtering more than twice. I also read that ice cubes help with the dropping when using AR, does the same apply for AP?
 

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