Miller process Miller process The Miller process is an industrial-scale chemical procedure used to refine gold to a high degree of purity (99.95%). It was invented by Francis Bowyer Miller ( patented 1867). This chemical process involves blowing a stream of pure chlorine gas over and through a crucible filled with molten, but impure, gold. This process purifies the gold because nearly all other elements will form chlorides before gold does, and they can then be removed as salts that are insoluble in the molten metal. When all impurities have been removed from the gold (observable by a change in flame color)
Industrial processes Industrial processes Industrial processes are procedures involving chemical, physical, electrical or mechanical steps to aid in the manufacturing of an item or items, usually carried out on a very large scale. Industrial processes are the key components of heavy industry. These may be applied on their own, or as part of a larger process. The availability of electricity and its effect on materials gave rise to several processes for plating or separating metals. There are several physical processes for reshaping a material by cutting, folding, joining or polishing, developed on a large scale from workshop techniques. The physical shaping of