Normally all furnaces or vacuum chambers where precious metals may evaporate have their walls covered with some metallic foil, e.g. aluminum foil (while the worked metal is heated at very high temperatures by the electron beam, the walls remain much colder), on which the precious metals lost during heating will condense.

After a production batch, the metallic foil is replaced and the used foil is chemically processed and almost 100% of the precious metals are recovered.