The Cathode Overvoltage in an Amalgam Cell

Abstract

It is important to determine the flow rate of mercury in designing a large capacity amalgam cell of 500-800 kA, because its operation is disturbed by the formation of the film and discharge of hydrogen ion on the mercury cathode. In the case of high flow rate of mercury, the cathode potential in amalgam cell was measured, and the results were summarized as follows:
( 1 ) The cathode overvoltage is only 30 to 80 mV.
( 2 ) Sodium concentration on the surface of the mercury cathode is appreciably high at high current density.
( 3 ) The thickness of the boundary layer was an order of 10-3 cm under high flow rate of mercury as 50 to 110 cm/sec.