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)
Commodity chain metaphor for this concept because things are interconnected in so many ways, not just a mere straight line. This source explains global commodity chains in depth. Commodity chain A commodity chain is a process used by firms to gather resources, transform them into goods or commodities, and finally, distribute them to consumers. It is a series of links connecting the many places of production and distribution and resulting in a commodity that is then exchanged on the world market. In short, it is the connected path from which a good travels from producers to consumers. Commodity chains can be unique