Stripping glassware with HCL-CL

I've been stockpiling PM bearing scrap for about a year now and I figured it's time to try my hand at recovery. I thought I'd go after something easy at first and try stripping the small mountain of glassware that I have collected over the winter. I have about 175 pieces total and decided to use HCL-CL to strip them. What I did is mixed about 750ml of 32% HCL with about 50 ml of chlorine bleach. The solution fizzed and stunk but it stripped the gold well. I am doing this outdoors and I make sure I'm up wind.


All would go well for about an hour then the solution would loose it's effectiveness. What I'd do is give it another shot of bleach and I could strip again. Agitation helped a lot to speed the stripping. After about 125 glasses, mugs and plates I noticed that even after giving the additional shot of bleach the solution grew lazy and would barely strip any more. I suspect the solution is now diluted with water which was dragged in by the pre-wash of the glassware. Also I suspect I was adding water with every additional shot of soduim hyperchlorite. That and I now have no clue what concentration of HCL I have.
My question is how would I kick the solution so it will strip again? I have about 50 pieces to go. I'm assuming the light yellow tint of my solution is the gold chloride? I know it's not as dark as I'd like to see :lol: I'm not expecting a huge button at the end of all this.

I have over a litre of stripping solution. Would it be acceptable to concentrate the solution on a hotplate to drive out the water? Then I would add HCL and bleach to start the process again to finish stripping? Or, am I done with this solution and now time to drop the gold?

Thanks

Trevor

Evaporating it down will be fine, just be sure you don't boil it so had your gold goes up in smoke. Once you see salts form add some more HCl and bleach to strip more pieces.

Don't expect too much gold, it's very thin on the china and glassware.

Steve

You will have a lot of HCL still available so just add a little more bleach, with nearly a liter of acid you can leach a lot of glassware.

jim

I boiled down the solution to about 1/3 it's original quantity. I noticed I was losing HCL during the boil, I hope I didn't lose any of my PM values by doing this. After it cooled I noticed the formation of clear crystals on the bottom. The color of the solution deepened. I'll add HCL and chlorine bleach to continue stripping what glassware I have left. LOL, the wife keeps bringing home more everyday, maybe I'll never finish :roll:
I'm really curious to see how much gold drops from this when I'm done.

I'm not fond of the term "boil." I rarely boiled anything, since there are more losses from the boiling action. For any solution, assuming it's not under pressure, you can't get it any hotter than the boiling point. Whatever you are doing, if you bring the solution to near-boiling, it will evaporate nearly as fast.

resabed01 said:

I boiled down the solution to about 1/3 it's original quantity. I noticed I was losing HCL during the boil, I hope I didn't lose any of my PM values by doing this. After it cooled I noticed the formation of clear crystals on the bottom. The color of the solution deepened. I'll add HCL and chlorine bleach to continue stripping what glassware I have left. LOL, the wife keeps bringing home more everyday, maybe I'll never finish :roll:
I'm really curious to see how much gold drops from this when I'm done.

Click to expand...

Paitence is a virtue.

Well, I finished stripping whatever glassware there was. After that I heated the solution to drive off any excess chlorine. Then once it cooled I added SMB and dropped the gold. The results were less than impressive but still nice to know the process works. In all there is .33 grams of brown gold powder in the filter paper. Hardly worth firing up a torch for. I'll add this to a 800g batch of pins I'm currently doing.
I'm also in the process of setting up a sulphuric cell to strip about 20lbs of costume jewelry I've accumulated.
Thanks to this site and it's members I'm learning a lot.