Do I have copperas?

After incineration of magnetic chips and sieving it, I decided to put all metal material into the mason jar and covered it with really old battery acid. I was hoping to dissolve some, or all iron material, to free gold still attached to it. After about a year of very slow bubbling, I notice that nice green crystals are forming at the bottom. I redissolved and decanted it into another container and left it there for few months to recrystallize. While solution was evaporating down, these nice green crystals started to form. I think, I have made unintentionally copperas, but not 100% sure. Any Idea? Thanks.

Looks like it. This is some copperas crystals I made using diluted sulfuric acid from a deplating cell and some iron from a computer case.


I redissolved it, filtered and stored the solution in a air tight bottle. Whenever I need some copperas I just pour it straight from the bottle. It kept fresh for over a year now.

Göran

yellowfoil, yours might not be quite as pure as Göran's, depending on the "metals" you dissolved, but it's probably primarily copperas.

Dave

When it was "redissolved" (few months ago) nothing remained undissolved?

Thanks for your input. There was still most of the magnetic material from chips left undissolved. I decanted all greenish liquid, which looked pretty saturated, because after short time in the open, crystals started to form. Hope it will help.

Yellowfoil, yours appear to me to be just as good as Göran's.
The fact that you have already recrystallised them means you're already increasing their purity.

I made mine from filtered*, hardware store grade, copper sulfate solution and bright nails. I would photograph them to contribute, only I started redissolving them just last night. You see, I had dried them on an absorbent, plastic, membrane material but they became fixed to the membrane, tearing it on removal. So I will dissolve and filer and recrystallise...

* It tends to be a bit cloudy, from additives.

The purity of copperas isn't critical, we use it on quite dirty solutions without problem.

If you just collect the crystals before all the liquid has evaporated they should be quite pure.
When crystals forms most impurities will be left in the liquid. This can be used as a way of separating different metals in solution into pure compounds, for example silver nitrate and copper nitrate forms clear silver nitrate and deep blue copper nitrate crystals that can be separated manually. (I'll write more about that experiment later, it's still ongoing.)

Göran

Thanks you Göran, Dave, Lino146 and Jason_recliner (hope I didn't miss anybody) for fast response. I am glad that my project turned this way, because I used almost useless old battery acid and low grade gold bearing material, which I wasn't ready to work with anyway. I actually recrystallized it one more time and each time I removed crystals before all liquid evaporated. I wasn't rushing anywhere and I just put into the practice, what I learned in school decades ago. Good to know that it is copperas indeed, and that it doesn't need to be so pure. Göran, please keep me (us) posted on development of your silver/copper nitrate separation project. I am very interested. Thanks.

I started a separate thread with the silver nitrate crystals here:
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=37&t=26647

Göran