Electroplating continued electrolytes

However, it can be assumed for most electrochemical applications of ionic liquids, especially for electroplating, that suitable regeneration procedures can be found. This is first, because transfer of several regeneration options that have been established for aqueous solutions should be possible, allowing regeneration and reuse of ionic liquid based electrolytes. Secondly, for purification of fiesh ionic liquids on the laboratory scale a number of methods, such as distillation, recrystallization, extraction, membrane filtration, batch adsorption and semi-continuous adsorption in a chromatography column, have already been tested. The recovery of ionic liquids from rinse or washing water, e.g. by nanofiltration, can also be an important issue. 

The first attempt to electrolytically deposit an aluminum layer was carried out more than 100 years ago. Since then, other methods of electrolytic aluminum deposition were continued to be published. However, none stood up to careful scrutiny. The wish to electrodeposit a newly-to-be-erected statue of William Penn with aluminum led the city council of Philadelphia to be swindled. A charlatan claimed to be able to complete the electroplating process by using a secret recipe. The aluminum was to protect the statue from corrosion in the sea climate. The contractor had the city finance the construction of the world s largest eletroplating plant. Only subsequently would the defraud be publicized, when it became clear that zinc had been elec-trodeposited instead of eiluminum [203]. 

The cell is of a very simple design. It consists of a bipolar stack of carbon steel sheets whose cathode faces are smoothly electroplated with cadmium to a thickness of 0.1-0.2 mm. The anode-cathode gap is fixed with spacers at about 2 mm and the steel sheets are surrounded by insulating skirts to reduce the bypass currents. The electrolyte is fed uniformly across the parallel interelectrode gaps to give a flow velocity of 1-2 m s" The emulsion is recycled through the cell from a reservoir and a fraction of the organic phase is removed continuously for extraction of the product. The process is run so that the organic phase in... 

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