Hello all
So I am doing some sample tests on some boards with a lot of gold flash plating I have completely depopulated the board by hand except for a couple boards that had a few items that were soldered to them and would not come off without heat.
So the first batch went into ap and after a couple days of running the bubbler most of the gold was floating in the ap so I removed bubbler let settle and filtered getting more gold foils than expected. The boards that were free of all metals were removed new boards added and same filtered solution pored back on the second batch after couple days there was no progress on this batch so I added more HCL and a few ml h2o2 another day and things seemed to be working again.
Now this is where I have run into issues I ended up getting busy with work and stuff and had set this aside for a couple weeks with the bubbler going. Got back to it and had this almost black solution so I removed the boards and filtered the solution. No gold or much of anything in filter. Stannious test causes the dark drop of solution to go clear first then after 10-15 minutes there is a ring of dark brown almost black. So I went to cement everything copper would cement out. After 24 hours I had a solution that was crystal clear from about an inch from the top down and the top inch was very dark went to remove the copper coil and it caused the black top inch to disperse and turn the whole thing back dark these pics is from after this point dark one is after it mixed and the second is from after another 24 hours of the copper being in it. The first time the dark floated higher
I have taken a small sample and added a few drops nitric acid the solution turn yellow. This solution gives a positive stannious test for gold.
So before I try this route for making AR out of the Ap then drop the gold with either SMB or Copperas thought I would ask here for thoughts. Like I said this is just a test to see if it will get the flash plating off boards with solder and legs from components still on the boards.
So I am doing some sample tests on some boards with a lot of gold flash plating I have completely depopulated the board by hand except for a couple boards that had a few items that were soldered to them and would not come off without heat.
So the first batch went into ap and after a couple days of running the bubbler most of the gold was floating in the ap so I removed bubbler let settle and filtered getting more gold foils than expected. The boards that were free of all metals were removed new boards added and same filtered solution pored back on the second batch after couple days there was no progress on this batch so I added more HCL and a few ml h2o2 another day and things seemed to be working again.
Now this is where I have run into issues I ended up getting busy with work and stuff and had set this aside for a couple weeks with the bubbler going. Got back to it and had this almost black solution so I removed the boards and filtered the solution. No gold or much of anything in filter. Stannious test causes the dark drop of solution to go clear first then after 10-15 minutes there is a ring of dark brown almost black. So I went to cement everything copper would cement out. After 24 hours I had a solution that was crystal clear from about an inch from the top down and the top inch was very dark went to remove the copper coil and it caused the black top inch to disperse and turn the whole thing back dark these pics is from after this point dark one is after it mixed and the second is from after another 24 hours of the copper being in it. The first time the dark floated higher
I have taken a small sample and added a few drops nitric acid the solution turn yellow. This solution gives a positive stannious test for gold.
So before I try this route for making AR out of the Ap then drop the gold with either SMB or Copperas thought I would ask here for thoughts. Like I said this is just a test to see if it will get the flash plating off boards with solder and legs from components still on the boards.
