An investigation was conducted on three samples of mill tailings from the Blackbird Mine tailings pond near Cobalt, Idaho, to determine if cu, CO, and ni could be extracted and concentrated. The samples, obtained by the U.S. Bureau of Mines, represented both the sand and slime areas of the pond. Bulk sulfide mineral flotation on the two sand tailings samples resulted in cu recoveries of 74 to 86 pct, CO recoveries of 71 to 89 pct, and ni recoveries of 90 to 95 pct, with average concentrate grades of 2.75 pct cu, 2.41 pct CO, and 0.14 pct ni. The recovery of cu, CO, and ni from bulk sulfide mineral flotation on the third sample from the slime end of the pond was 68, 54, and 90 pct, respectively, at percent grades of 0.68 Cu, 0.70 Co, and 0.37 Ni. Reduction roasting of dead-roasted concentrates from the sand tailings followed by leaching with ammonia-ammonium sulfate solutions extracted 92 pct cu, 87 pct CO, and 86 pct ni.
Proc. 5th Miner. Waste Util. Symp., Chicago, Illinois, Apr. 13-14, 1976, PP. 62-67