Changes

The refining process starts with melting of a homogeneous alloy in granulate or ingot form. Using different analytical methods the exact precious metal content is determined. Once verified the actual refining and separation of the precious metal components is performed using a sequence of electrochemical and chemical processes.

The widely used electrolytic refining of silver performed by the “Moebius” – process has great economical importance. Plates of continuously cast highsilver-content material are dissolved as the anode in a nitric acid electrolyte solution. Through the influence of an electrical field the silver ions move to a steel cathode where they are reduced to silver metal and deposited as pure silver in the form of crystalline dendrite particles. The process is adjusted in a way that allows the non-precious components to stay in solution or be collected as sludge in bags that surround the silver anodes. The silver reclaimed in this way has a purity of 99.99%. After relatively simple cleaning drying process silver is usually re-melted into ingots or granulate and returned into the manufacturing process, e.g. for contact materials.