# HCl + Bleach and gold bonding wire



## realtechedo (Jul 8, 2017)

Goodmorning to all in this forum. My very question today is "Can I use HCl and Bleach to dissolve gold bonding wires from incinerated chips? especially where I do not have access to Nitric acid. If this will work well, what will be the appropriate process to go about it for better result if anyone has done this before. Thanks for your time and I await your candid response...


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## Lino1406 (Jul 8, 2017)

HCL + bleach give Chlorine what does the job


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## realtechedo (Jul 8, 2017)

Lino1406 said:


> HCL + bleach give Chlorine what does the job



Thanks and copied


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## FrugalRefiner (Jul 8, 2017)

Clean up the material the best you can with a sluice or panning first. Get it as clean as you can.

Then put the cleaned bonding wires in a beaker and cover them with HCl. Add the bleach in tiny increments. By tiny, I mean just a couple of ml at a time. When you add bleach to HCl, as Lino said it releases chlorine into the solution. If you add too much at a time, the excess just gasses out of solution and is lost and wasted. Also, since bleach is basic, it will gradually neutralize the HCl. So add a couple of ml of bleach, stir, stir, and stir some more. Give it time to work. After a few minutes, you can add a couple more ml of bleach and stir, stir, stir some more.

Dave


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## anachronism (Jul 8, 2017)

Bonding wires in HCl/bleach will be a relatively long process because of the relatively small surface area. Yeah it should work but I have never done it because I prefer AR but I can't definitely say how well it WILL work. 

Dave have you done these in this manner?


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## realtechedo (Jul 8, 2017)

FrugalRefiner said:


> Clean up the material the best you can with a sluice or panning first. Get it as clean as you can.
> 
> Then put the cleaned bonding wires in a beaker and cover them with HCl. Add the bleach in tiny increments. By tiny, I mean just a couple of ml at a time. When you add bleach to HCl, as Lino said it releases chlorine into the solution. If you add too much at a time, the excess just gasses out of solution and is lost and wasted. Also, since bleach is basic, it will gradually neutralize the HCl. So add a couple of ml of bleach, stir, stir, and stir some more. Give it time to work. After a few minutes, you can add a couple more ml of bleach and stir, stir, stir some more.
> 
> Dave




Thanks FrugalRefiner, but should I always cover it when the bleach is added in small increments


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## FrugalRefiner (Jul 8, 2017)

Jon, I agree, as fine as they are, bonding wires are kind of thick for HCl / bleach. I would prefer AR too, but he said he can't get nitric in his opening post. I have never personally used it but I know others have if they exercised patience. That's why I recommended small additions with lots of stirring.

realtechedo, I'm not sure I understand your question, so I'll answer from two directions. When I said to cover the wires in HCl, I meant to add enough HCl so that the wires are completely covered by the HCl liquid - so there are no wires sticking up through the surface of the HCl.

If you mean keeping a cover, like a watch glass or a saucer, over the beaker while you're running the reaction, that's a good idea too. I think kadriver posted some videos where he used a pipette to squirt some bleach into a beaker covered with a watch glass.

Dave


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## nickvc (Jul 9, 2017)

With bonding wires instead of using Hcl bleach I'd go for poor mans AR as others have stated the dissolution will be a very long process using Hcl bleach.


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## realtechedo (Jul 9, 2017)

FrugalRefiner said:


> Jon, I agree, as fine as they are, bonding wires are kind of thick for HCl / bleach. I would prefer AR too, but he said he can't get nitric in his opening post. I have never personally used it but I know others have if they exercised patience. That's why I recommended small additions with lots of stirring.
> 
> realtechedo, I'm not sure I understand your question, so I'll answer from two directions. When I said to cover the wires in HCl, I meant to add enough HCl so that the wires are completely covered by the HCl liquid - so there are no wires sticking up through the surface of the HCl.
> 
> ...



Thanks once again FrugalRefiner, I will give it a try and watch my patience in my next practical. And you really answered my question . It was really about covering the beaker that will contain the gold bonded wires and the hcl +bleach solution. If I succeed, I will let this forum know this. God bless


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## patnor1011 (Jul 9, 2017)

Post pictures of your concentrate first. If there is still a lot of ash/soot there it will work to some extent. 
If your concentrate does contain small tiny wires (if feedstock was IC or acid untreated BGA) then I am afraid it will not work efficiently. 
While you may dissolve some gold initially it will precipitate back on any metal which will be present there.
HCl+Bleach is not a way to go unless you will be happy with "some" recovery but you will not get most of the gold no matter how hard you will try. 
If you do not have nitric then the best option for you left is what Nickvc suggested. Get some potassium nitrate or sodium nitrate and go poorman's AR way.


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## realtechedo (Jul 9, 2017)

patnor1011 said:


> Post pictures of your concentrate first. If there is still a lot of ash/soot there it will work to some extent.
> If your concentrate does contain small tiny wires (if feedstock was IC or acid untreated BGA) then I am afraid it will not work efficiently.
> While you may dissolve some gold initially it will precipitate back on any metal which will be present there.
> HCl+Bleach is not a way to go unless you will be happy with "some" recovery but you will not get most of the gold no matter how hard you will try.
> If you do not have nitric then the best option for you left is what Nickvc suggested. Get some potassium nitrate or sodium nitrate and go poorman's AR way.




Thanks Patnor1011, I have copied all you said, I will definitely share pics when I have fully incinerate all the chips...


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## kurtak (Jul 9, 2017)

What Pat & Nick said :!: 

Poor mans AR :!: 

I would NOT use HCl & bleach :!: 

Kurt


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