Calamine brass slowly phased out as zinc smelting techniques were developed in Europe, which produced metallic zinc more suitable for brass production than calamine. However, the conversion away from calamine brass manufacture was slow; a British patent was awarded to William Champion in 1738, but the alloying of metallic zinc and copper to produce brass was not patented until 1781 (by James Emerson), and calamine brass mills persisted in South Wales until as late as 1858. The slow diffusion of this technology was probably the result of economic factors. Calamine brass Calamine brass is brass produced by a particular alloying technique using
Iron ore by Fe oxidation on the anodic zone inside the pit must be quickly compensated / neutralised by negative charges brought by the electrokinetic migration of anions in the capillary pit. Some of the electrochemical processes occurring in a capillary pit are the same than these encountered in capillary electrophoresis. Higher the anion electrokinetic migration rate, higher the rate of pitting corrosion. Electrokinetic transport of ions inside the pit can be the rate limiting step in the pit growth rate. Iron ore Iron ores are rocks and minerals from which metallic iron can be economically extracted. The ores are usually rich