Constant current electrochemical reactivation in electroplating of gold:
In 1950 The United States Bureau of Mines, Zadra and other developed carbon-in-pulp process, which is put granular activated carbon directly into mixed slurry ore powder and cyanide pulp, to gernerate cyanide gold adsorb by activated carbon, through multiple reverse adsorption, concentration enrichment, then followed by desorption, to get gold, in this process, granular activated carbon can be repeated application of regeneration. 1973 US Homestake Mining Company built its first production CIP plant in extract gold. Then, South Africa has built a number of similar mines plant.
Rectifier-Granular activated carbon electrochemical reactivation apparatus:
Rectifier is a apparatus to provide a consists of power supply of electrochemical reactivation in electroplating of gold from granular activated carbon. The electrical power was supplied by a potentiostatic controller and an accessory power supply. This unit was used as a transformer–rectifier to provide constant current.