Reuse of HCL

[Oz]

It is the copper that does the work in AP. Steve has a PDF on his site that will tell you more than you probably want to know about it.

 

[lazersteve]

The AP reaction should really be called the Copper II Chloride reaction as this is the active ingredient.

Insoluble Copper I Chloride builds up and causes the dark brown color and off white to gray colored salts in the gold foils. Bubbling air or adding a small amount of hydrogen peroxide in the presence of HCl will convert the CuCl into reactive CuCl2 (Copper I Chloride to Copper II Chloride).

Steve

 

[wop1969]

It is the copper that does the work in AP. Steve has a PDF on his site that will tell you more than you probably want to know about it.

I read it oz Just like you said , that is the only way I am starting to understand the AP proccess even enough to attempt to make the statement i did

So if I am undestanding this putting copper in AP creates CuCl and that is what keeps the reaction going?

What I should have said:So if I am undestanding this putting copper in AP creates CuCL2 and that is what keeps the reaction going when "steve said:you bubble air in it or ad peroxide to it" you regenerate it.

Babysteps

 

[steveonmars]

I have some AP solution that is very dark green. I add more peroxide and it keeps right on working but I've now got so much copper that any gold in solution is dropping out into a brown powder. I'm adding this to the foils to redissolve in HCL/Cl later. I started a new batch of AP.

To regenerate the old batch do I remove the copper (after testing for gold is negative) by placing some scrap steel in the bucket and then when the copper is gone do I just add more peroxide to rejuvinate the solution?

Thanks,

Steve

 

[Anonymous]

No once you take the copper out it is done, I know there is a ferric cloride type compound use to ecth pc boards but I do not know if the ferric chloride resulting from adding iron to the spent ap can be converted to it or not.

jim

 

[steveonmars]

Does that mean I don't need to remove the copper at all? Just siphon off the liquid once in a while to get the gold that precips and add more peroxide?

I looked again and the color is almost a dark brown now instead of green. For the price of a gallon of HCL should I just start a new batch when it gets like this. I'm running 100's of cell phone boards right now which have a lot of copper so it's getting used up fairly quick.

Steve