Hey all so I just ran into a snag I am in the process of cleaning up some waste for some tests I have done and got pulled away from for a bit and of course my note book that had what was what listed disappeared (wife kid not sure which one) found outside and unreadable. So I took and filtered and combined everything HCL, AR, and nitric into one vessel about 3 liters total acid and rinse water. Added my copper coil 1/4”x3/8” in about a 5 inch diameter coil with bubbler for agitation let sit for two days had a black cement on bottom of vessel and some stuck to coil appeared nothing else was cemented the second day so I pulled the coil and set into another vessel and used spray bottle to rinse off as much of the black cement. Left solution for 12 hours to settle while I went to work came home and found the solution went from a dark green to a bright blue and all the cement is gone. Will test solution tonight when I get home. My best guess is it created cucl2 when trying to cement out any values. So my question. the black cement (which I have a very small amount of in the water from rinsing the coil) would this be PM’s or something else? I can get pics later if needed.
Like I said this was from a bunch of small tests on some heavy flash plating on boards there was some small surface mounts resistors, and caps the little tiny ones everything else was removed before running samples to try and find a way to get the plating off the boards as I have a lot of these board with the heavy flash plating from various industrial boards not consumer grade.
The test were run on just a handful of small boards with much less gold plating. Still working on finding a feasible way to get this plating without a lot of waste as some of this plating is contact plating for other board and buttons and is just as thick or thicker than gold plated fingers but through the whole board not feasible to cut like fingers. See first pic I have about 8-10 lbs of boards like this. And more with a lot of just flash plating through the whole board second pic. Mainly looking at the ones like the first pic but using ones like the second pic for testing the second pic show the surface mounts that were left for the testing I did.
Before I continue I am going to warm in oven to melt solder with a air vibrator that is used on hoppers to shake the solder and the rest of the surface mount from the boards. Then soak in HCL to dissolve any tin left. Rinse incinerate run through impact mill then pan out as much ash as possible then recover gold and other pm’s.
That’s my plan but any input would be appreciated.
Thanks
Jim
Like I said this was from a bunch of small tests on some heavy flash plating on boards there was some small surface mounts resistors, and caps the little tiny ones everything else was removed before running samples to try and find a way to get the plating off the boards as I have a lot of these board with the heavy flash plating from various industrial boards not consumer grade.
The test were run on just a handful of small boards with much less gold plating. Still working on finding a feasible way to get this plating without a lot of waste as some of this plating is contact plating for other board and buttons and is just as thick or thicker than gold plated fingers but through the whole board not feasible to cut like fingers. See first pic I have about 8-10 lbs of boards like this. And more with a lot of just flash plating through the whole board second pic. Mainly looking at the ones like the first pic but using ones like the second pic for testing the second pic show the surface mounts that were left for the testing I did.
Before I continue I am going to warm in oven to melt solder with a air vibrator that is used on hoppers to shake the solder and the rest of the surface mount from the boards. Then soak in HCL to dissolve any tin left. Rinse incinerate run through impact mill then pan out as much ash as possible then recover gold and other pm’s.
That’s my plan but any input would be appreciated.
Thanks
Jim