Metaphore said:
Took a much closer look and shined a flash light through it. Close enough to get a tiny whiff through the respirator. Sucked. But I did see that there is a reaction. It's very slow and very hard to see in the extremely dark liquid.
The gold isn't covered, it's all exposed. I took the ceramic plates off with a blow torch and the rest are the pins and the top cover. When I drained the AR, I saw the top covers flaking and about 10% of the pins intact. I could also see some gold inside the processor, where the ceramic cover used to be. It was all exposed.
@NobleMetalWorks, what does expanding the solution mean?
Should I be concerned about the color of the solution? With the foils and black powder, my solution was a nice deep gold color. This one seems like it has a ton of copper in it. Will I need to do anything different with the AR to drop the gold?
Thanks!
Your solution can only hold so much dissolved metal before it becomes exhausted. Metal is dissolved into solution according to the reactivity series:
https://en.wikipedia.org/wiki/Reactivity_series. It seems your solution is pregnant with dissolved metals. When you add acid, it is most likely attacking the exposed metals under the gold plating and thus making it seem like your solution is no longer dissolving gold.
Think of it like this. You introduced many different types of metals into a solution of AR. The metals that are exposed are the first to dissolve into solution. Since you have gold plating that was covering base metals, the gold plating goes into solution until the base metal is exposed, then the AR solution attacks the base metals instead of the gold, you can refer to the reactivity series so that you might understand what I mean. The metals at the top of the scale I posted the link for, will dissolve into solution before the metals at the bottom. Once enough gold has been dissolved to expose the base metals to AR, the AR no longer attacks the gold, but rather the base metals. Until the base metals are completely dissolved, or you remove them, your AR solution will only slowly dissolve gold into solution.
This is one of the many reasons why it's better to remove the pieces that contain gold, from the ones that do not. As well, we try not to dissolve metals into solution that might cause issues in precipitation of the metals we are after. If for example the heat spreader of the CPU is made of Kovar, you are metals into your solution that you don't really want to deal with.
When a solution becomes saturated with base metals, it no longer can dissolve or hold in solution anymore metals. I would suggest removing those parts of the CPUs that still have gold on them, and dissolve in a new AR solution.
The heat spreader also has solder that might contain lead solder which could also cause problems and should be removed prior to precipitating gold.
When I made the suggestion to expand your solution, what I am meaning is to provide more room for metals to be dissolved into solution. You can expand a solution by adding more acids, or water or? All dependent upon what type of solution you have, and what your intent is. You expanded your solution when you added more acid, but as the acid was attacking the base metals instead of the gold, it seemed that your AR solution was not working, or working on slowly.
Hope this helps...
Scott
Scott
