Guess what this stuff is. It is silver blackened gradually by trace sulphur content in air. I got it from customer somewhat 25 years ago. Then a test was undergone to see whether a ratio of silver/stainless steel anode area could keep the silver concentration well in an electroplating solution for 18k gold alloy metal deposit with the following conditions:
potassium cyanide 99 g/l
silver 1.8 g/l as cyanide salt
gold 4.5 g/l as cyanide salt
taurine 1g/l
ethylene diamine 1.5ml/l
sulphamic acid 3 g/l to pH 11
18-23 deg.C,
0.5ASD cathode current density
3mins./micron plating speed
All are just as clear as what happened yesterday！