Newbie a/p solution question

[Xsvfan1]

Ok so I've been practicing different stuff with a/p solution. I've been collecting and slowly learning the chemicals.

Well I've been doing fingers a few times and I've had an issue with keeping it warm while storing.

Today I started a batch of pins. When the reaction started it became very hot... like almost to hot to hold.
I know energy causes heat but I haven't experienced it before with my small amount of foils from fingers...

My question is this.... is it a good sign of how hot it's getting or would it be a sign of a metal type I didn't find.

Prolly dumb question just haven't seen a reaction of cold acid show this much energy.

 

[Lino1406]

A/p normally reacts with copper to produce copper solution. The heat produced is a thermodyamic entity, depending on this three components amounts, and hardly on the coolness of the acid

 

[BShan]

I should mention first I'm a learner too, Lino actually knows what he talks about. I try to be more accurate with my wording like "I think" and "Maybe", but consider this post as the blind helping the blind.

I think what Lino is saying is that the reaction wiht copper does create a little heat which may be measured but may not be obvious. Perhaps if a metal is more reactive than copper, the reaction rate is higher and the heat becomes more obvious.

I'm still in experimental phase as well, and none of my reactions have appeared vigorous. The most energetic one I've had was with mixed, low-grade, dirty (has solder) pins. Bubbles were observed forming more quickly, though not so quickly as to cause a "boiling" appearance. No noticeable increase in heat, but this stuff was outside so it was already a little warmer than room temperature. I was not using thermometers.

Depending on yoru quantity, you might consider the sulfuric cell. Recover the gold without needing to dissolve the entire mass of baser metals. I do kind of see some value (speaking as a hobbyist, not a professional) in keeping all the waste solutions the same type of solution (metal chlorides), but a chemist or professional recycler would view differently because they know better what to expect.

Here's a neat thread where they concluded that in a perfect world, 1lb of 32%HCL should be capable of converting over 2.5lb of copper to CuCl2. https://goldrefiningforum.com/phpBB3/viewtopic.php?t=17081