MINI PILOT PLANT EVALUATION OF THE AVR PROCESS FOR THE LAS CRISTINAS GOLD PROJECT

摘要

The feasibility of recovering cyanide and copper from a gold mill barren solution was evaluated in a small AVR pilot plant. The campaign lasted 64 hours, during which time about 4,000 L of gold mill barrens solution were processed. The results showed of gold mill barren solution were processed. The results showed that AVR is an effective technology for recovering cyanide and copper from barren solutions. Under the best conditions, the copper precipitation and the cyanide volatilization attained 94 percent and 98 percent, respectively. Using 5M NaOH as the absorbent, practically all the HCN gas was recovered in the form of a concentrated NaCN solution containing 70 g/L free CN. Basic engineering design parameters applicable to a large-scale operation were obtained, including the Henry's Law constant and the mass transfer coefficient for HCN gas.