White Paper:

Eliminating Mercury from Chlorine Production

Posted 5/15/2012

The worldwide chlor-alkali industry produces around 60 million metric tonnes of chlorine annually. Nearly all industrial chlorine production is by the electrolysis of brine (sodium chloride solution). Both chlorine and sodium hydroxide, the other product of this process, are basic raw materials for the chemical industry and as such world demand follows worldwide economic trends, and is particularly strong in the developing economies of Asia. Traditionally, the brine electrolysis was carried out in cells using iquid mercury as the cathode. This process has the potential for loss of mercury into the environment and into the product. Environmental concerns have led to a steady decline in chlorine production by this method, which is being superseded by the mercuryfree ”membrane process”. The efficiency of the membrane process can be impaired by the presence of trace impurities in the brine. To control the quality of the brine, it is necessary to measure these...