Gold doesn't seem to be dissolving in HCL+Bleach

[VictorMonopoly]

So I've arrived at my first instance of opinions needed. I removed 1,106 grams of gold finger from PC memory and then removed the foils via an AP bubbler for about a week. Filtered, rinsed, dried. In a Pyrex beaker I poured in 200 ml of muriatic 31.45% and then 100 ml clorox 8.25% SLOWLY. I did this outside on a 95 degree day with some breeze. After sitting overnight there's still foils left. A lot.




Now I wouldn't think that it's too saturated with gold already. I didn't do a second AP run on the foils, could I have copper in the solution halting my progress? Could the breeze outside have pushed out the chlorine gases enough that the mix isn't right? Also if I have used any terminology incorrectly, forgive me for I am not a chemist just a fella.

 

[FrugalRefiner]

When you say you added the Clorox slowly, do you mean you drizzled it in over a period of a minute or two, or do you mean you added a few ml and let it work, then came back later and added a few ml more, etc.? When you add the Clorox, it releases chlorine into the solution which oxidizes the gold. But the chlorine doesn't stay in solution long before gassing out. You want to add a bit, mix it well to get the chlorine to contact the gold, then wait a while, then add a bit more. With each addition, you want to mix the solution, otherwise the foils on the bottom are protected by those above them.

95 degrees is pretty warm. Cool solutions hold more dissolved gasses than hot ones. On a hot day, the chlorine will gas off more quickly.

The solution looks pretty good. If it were mine, I would let it settle well, then decant the clear solution off the remaining solids. Then add some fresh HCl and begin some more Clorox additions. When all the solids are dissolved, you can add the solutions together and treat the whole batch to eliminate any excess chlorine (either heat or let it sit for 24 hours), then add the precipitant of your choice.

Dave

 

[VictorMonopoly]

Okay so that may be it. I drizzled a few ml, waited a minute and then drizzled a few more, and so on and so on with mixing in there but not necessarily right after each small pour. I will take your suggestion. I gotta say this has been a fun experience for me.

 

[butcher]

Just some things to keep in mind: bleach is a basic solution, it can neutralize acid. Using a large amount of bleach (at one time) can change your acid to salts, heating or a hot day the chlorine can be driven out of solution faster, Bleach contains a lot of water, HCl acid itself is mostly water (with HCl gas dissolved in it) this means any metal chloride solution will be fairly dilute with water.

 

[glorycloud]

Patience really is the key with the Clorox additions. The key words are "let it work".
Yes, it bubbles and fizzes when it is first added but a quick stir (I use a glass rod)
and then five minutes or so to allow the CL to work before adding any more Clorox
is what you want to do.

Add Clorox, stir, WAIT, stir again to check for remaining foils and repeat as needed.

8)

 

[VictorMonopoly]

That's basically what I did the next time and it worked great.

Then precipitated it and basically one step left.

 

[Refining Rick]

Then precipitated it and basically one step left.

4 More steps:

1. Boiling H2O wash.
2. Hot (not boiling) HCl wash.
3. Boiling H2O wash.
4. Melt into a nice pretty precious gold button.
Looks great. Nice work. Can't wait to see the melt! I have only done the bleach/HCl method a couple times myself as I do not usually do foils, so this is learning vicariously though our forum for me.

 

[Topher_osAUrus]

Then precipitated it and basically one step left.

4 More steps:

1. Boiling H2O wash.
2. Hot (not boiling) HCl wash.
3. Boiling H2O wash.
4. Melt into a nice pretty precious gold button.
Looks great. Nice work. Can't wait to see the melt! I have only done the bleach/HCl method a couple times myself as I do not usually do foils, so this is learning vicariously though our forum for me.

More steps than that possibly, depending on the color of the washes.
Number 3 I sometimes have to do 4 or 5 times to get a neutral ph before melting.

It makes me wonder how much gold i lost, before i found the forum, that was volatized because of residual chlorides clinging to the powders. *sigh*

 

[Refining Rick]

More steps than that possibly, depending on the color of the washes.
Number 3 I sometimes have to do 4 or 5 times to get a neutral ph before melting.

It makes me wonder how much gold i lost, before i found the forum, that was volatized because of residual chlorides clinging to the powders. *sigh*

Ahhh!I have not been checking my ph after step 3. Great addition. I will be adding that to my routine. Thank you. Except now I too will sit and wonder how much I have lost..... :?:

 

[g_axelsson]

More steps than that possibly, depending on the color of the washes.
Number 3 I sometimes have to do 4 or 5 times to get a neutral ph before melting.

It makes me wonder how much gold i lost, before i found the forum, that was volatized because of residual chlorides clinging to the powders. *sigh*

Probably not much, any hydrochloric acid would boil off long before the gold started to react with it and if you have any base metal chlorides left then you haven't washed it enough from the start.

Göran

 

[Topher_osAUrus]

More steps than that possibly, depending on the color of the washes.
Number 3 I sometimes have to do 4 or 5 times to get a neutral ph before melting.

It makes me wonder how much gold i lost, before i found the forum, that was volatized because of residual chlorides clinging to the powders. *sigh*

Probably not much, any hydrochloric acid would boil off long before the gold started to react with it and if you have any base metal chlorides left then you haven't washed it enough from the start.

Göran

Well, that makes me feel at least a little bit better about it. Thanks Göran.