Also, when working with AP, when your solution becomes saturated with Cu II (Copper Chloride), you need to add more H20 (water) to expand your solution so the Copper Chloride can dissolve more Cu and make more Cu Chloride. It's like the movie "the blob" the more Cu it dissolves, the larger it can get, the more Cu it can dissolve. It's an ever expanding enterprise. So instead of creating a "new batch" all you need to do is one of two things. Either add more H20 to your Cu II solution, or if you do not have additional room to expand your solution, remove some of the Cu II solution and add water. Test the part of the solution you remove for values, you could possibly have Au in solution, but most likely if any dissolved it was cemented out when Cu converted to Cu II. You might have some dark powder on the bottom of your AP bucket, if you do there is a good chance that it could be Au that was cemented out. So any solution you remove, you should filter and test for values, and of course Au foils.
To remove the lids, you can use a torch, a regular propane torch works perfect for this. Hold the chip with a pair of pliers, heat the heat spreader "lid" until you see the braze/solder start to melt, then lightly tap the chip against metal, or a metal pan. Remember the lid is hot, so use a metal pan to knock the lid loose so that it comes off.
There are many different designs for ball mills, and many different ways of breaking up your chips. You could use a ball mill, and if doing a lot it would be a wise investment. I use two to good effect. However, if I don't have a lot of ceramic chips to run, simply holding the chip in your hand and hitting it sharply with a hammer will do the trick. Just break them up into 5-10 pieces each. So long as the acid can get to any gold wires that might be on the inside, you will do fine. If you do use a ball mill, you might want to also sift the powder after. Running the ceramic powder in AR will cause you a filtering nightmare.
One way to make a quick and dirty ball mill is to use a cement mixer. Just make sure the inside is clean and free of any Lime, if you transfer lime to your powder, and then try to process with acid, the lime will neutralize some of your acid, and cause you to use more than required.
Scott
