Electrochemical processes are incorporated into both the cleansing procedure as well as into the retrieval of the precious metal at the close of recycling.
In order to produce platinum sponge Heraeus possesses its own, specially developed electrolysis plant which is continually operated. Hexachloroplatinic acid is cathodically reduced in four consecutive cells to platinum sponge. Cathode and anode are separated from each other by a cation exchange membrane. The metal finally settles and forms sediment which can then be easily rinsed out of the cells. The pure metal is separated from the lather by means of filtration.
Rhodium sponge is produced using a similar method.
