Wohlwill process Wohlwill process The Wohlwill process is an industrial-scale chemical procedure used to refine gold to the highest degree of purity (99.999%). The process was invented in 1874 by Emil Wohlwill. This electrochemical process involves using a cast gold ingot, often called a Doré bar, of 95%+ gold to serve as an anode. Lower percentages of gold in the anode will interfere with the reaction, especially when the contaminating metal is silver or one of the platinum group elements. The cathode(s) for this reaction are small sheets of pure (24k) gold sheeting or stainless steel. Current is applied to the system,
Ultra-high-purity steam for oxidation and annealing high temperature combustion. Within its optimal operating range, torches deliver good purity. Pyrolytic systems can support a middle range of flow but have a difficult time with very low flow rates and low steam to hydrogen ratios when adding water vapor to a carrier gas. Also, thermal management of the heat profile of the furnace and incomplete combustion affect furnace performance. In selective oxidation processes, water vapor is needed with hydrogen and without molecular to oxygen. This allows for the oxidation of specific metals. Torches and catalytic system are not 100% efficient so low levels of oxygen may still enter