Dougplogan
Well-known member
I'll start with this is only my thrid time trying this step. I used hydrochloric acid and a few ml of nitric to put about ten grams of gold plating from several circuit boards. Basically when it was time to precipitate the gold it acted as expected when I added smb. Two teaspoons full and nice color change followed by a fast settling. Solution was warm or beacker was warm to the touch but not hot. After settling I did a stannous test and test was instant color. Which I expected because it looks like maybe a gram settled on bottom of beaker. Again the gold foil material was just over 10 grams so I expected atleast half that to drop. Anyways I added another teaspoon of smb at this point with a nice strong fizz reaction but nothing more dropping out. I might add not sure if this matters but solution is pretty acidic still. Only water used to dilute was the water I used to flush color out of previous container and through filter. Just curious what thoughts people might have? I'm going to leave till tomorrow and think and read.