METALLURGICAL DEVELOPMENT OF THE NQRTHMET DEPOSIT OF POLYMET MINING FOR RECOVERY OF COPPER, NICKEL, COBALT AND PRECIOUS METALS

摘要

The NorthMet project of PolyMet Mining is well advanced and ready to proceed to construction upon receipt of key permits. The NorthMet project will begin with an initial phase of separate copper and nickel concentrate production for sale followed by commissioning of the hydrometallurgical circuit for bulk concentrate leaching. The PLATSOL~(TM) process will be used for the treatment of the concentrate. The PLATSOL~(TM) process will dissolve all the metals of value to high levels of extraction in an autoclave, followed by a series of precipitation and SX/EW processes for recovery of final metal products. The final products from the commercial plant will include; Copper Cathode of LME Grade A Quality; Au and PGM Precipitate for Toll Processing; Mixed Hydroxide Product Containing Ni-Co-Zn; Synthetic Gypsum; The current design basis is for 32,000 short tons of ore per day to be processed through the refurbished Erie plant and a new hydrometallurgical refinery for metal extraction. Figure 10 shows how the hydrometallurgical plant will be integrated with the existing Erie facility.