Gold parting in 1860's Australia. It is able to refine gold up to 99.5% purity. The process involves blowing a stream of chlorine gas over and through a crucible filled with molten impure gold. Impurities in the gold form chlorides before the gold does and these insoluble salts are removed from the melt by skimming the surface. Invented by Emil Wohlwill in 1874, this produces the highest purity gold (99.999%). It is an electrolytic process using pure gold for the cathode (or titanium as a starter cathode) and chloroauric acid (gold chloride-hydrochloric acid) as the electrolyte; this is made by dissolving gold
Ultra-high-purity steam for oxidation and annealing processes are commonly used to generate TCO layers and modify crystal structures via grain size or defect repair. The ability to deliver water vapor free from atmospheric contaminants is critical to film integrity. The ideal water vapor for industrial manufacturing processes is extremely pure, moderate in temperature and free of extra oxygen or water microdroplets. In addition, this water vapor is ideally delivered in a range of flow rates from sccm to slm, into vacuum or atmosphere pressure environments for days or weeks at a time. Purity is paramount in avoiding contamination. Purity can be achieved by blending pure gases