Patent ID: 6679984
Filing Date: 2004-01-20
Classification: C22B,Y02P

Abstract:
A method for eluting a metal-cyanide complex comprising a gold-cyanide complex and/or silver cyanide complex from loaded activated carbon contained in respective first and second strip columns and recovering precious metal comprising respective gold and silver therefrom, the loaded activated carbon occupying respective first and second bed volumes of space in the first and second strip columns, respectively, the strip columns being selectively connectable in series and each strip column individually to an electrowinning device forming respective continuous loops, a strip solution being selectively flowable through the respective loops using a pump connected therewith, comprising the steps of:flowing the strip solution in a first continuous loop as barren strip solution from the electrowinning device through the loaded activated carbon in the first strip column and back through the electrowinning device as pregnant strip solution thereby at least partially depleting the loaded activated carbon in the first strip column to produce partially depleted loaded activated carbon in the first strip column, while the strip solution simultaneously elutes the metal-cyanide complex from the loaded activated carbon, and the electrowinning device removes the precious metal from the eluted metal-cyanide complex in the strip solution; flowing the strip solution in a second continuous loop as barren strip solution from the electrowinning device, through the partially depleted loaded activated carbon in the first strip column to produce substantially depleted activated carbon in the first strip column and through the loaded activated carbon in the second strip column thereby at least partially depleting the loaded activated carbon in the second strip column to produce partially depleted loaded activated carbon in the second strip column, and back through the electrowinning device as pregnant strip solution, while the strip solution simultaneously elutes the metal-cyanide complex from the loaded and partially depleted loaded activated carbon, and the electrowinning device removes the precious metal from the eluted metal-cyanide complex in the strip solution; and flowing the strip solution in a third continuous loop as barren strip solution from the electrowinning device through the partially depleted loaded activated carbon in the second strip column and back through the electrowinning device as pregnant strip solution, while the strip solution simultaneously elutes the metal-cyanide complex from the partially depleted loaded activated carbon, and the electrowinning device removes eluted precious metal from the eluted metal-cyanide complex in the strip solution.