As ore grades drop at today's large mines, and environmental regulations for waste discharges increase, economics drives new recovery innovations. This paper describes some technological advances in the recovery processes for copper, gold, silver, lead and zinc. It does not discuss pyrometallurgy. Korea, like many nations with industrial economies, consumes large amounts of these metals, and is dependent on overseas suppliers for nearly its entire supply. This paper also discusses how technology for recovery of metal now in Korea, for example from existing wastes, is important. Improved reagents for both leaching and froth flotation of copper minerals, plus bio-oxidation and pressure autoclaving for gold have improved metal recovery. Copper recovery by SX-EW is expanding rapidly, and the method is also commercial for zinc. Biooxidation of encapsulating waste materials and, in some instances, of the desired metal has reached commercial scale. Pressure leaching on a large scale solves specific problems for several metals. Improvements in gold and silver cyanidation include variants of activated carbon adsorption from solution. Zinc and lead still largely depend on flotation for the treatment of ores. However, innovation in hydrometallurgical extraction has been spurred by environmental concerns. Computer modeling and process control worldwide have likely led to the largest improvements in recovery. The limited availability of land, clean water and sites for waste disposal in many countries affects the economics of re-treatment of existing wastes. Some of the new technologies could be combined, for example in modular plants that can be moved between reclamation sites to economic advantage on the Korean Peninsula.

Nonferrous Metallurgy Korea Precious Metals Waste Dumps Tailings Imports Economics Grinding Bioleaching Flotation Solvent Extraction Pressure Autoclaving Chloride Leaching Cyanide Arsenic Industrial Nations

Alpers CN, Blowes DW, "The Environmental Geochemistry of Sulfide Oxidation," Washington, DC, American Chemical Society (1990)
Avecia, Inc., "Acorga Technical Library," CD ROM, Wilmington (2001)
Brierley C, "Commercial Status of Bioleaching," IN Randol Gold & Silver Forum '99, Denver:, Randol International Inc., 137 (1999)
Brittan M, Arthur B, Mining Eng., 52, 37 (2000)
Cathles LM, "Personal Perspectives from Attempts to Model the Industrial Scale Leaching of Copper-Bearing Mine Waste," In The Environmental Geochemistry of Sulfide Oxidation (ed. C.N. Alpers and D.W. Blowes, pp. 123-131), Washington, DC, American Chemical Society (1994)
Chae YB, J. Korean Recycling, 8, 37 (1999)
Chon HT, Ahn JS, Jung MC, "Heavy Metal Contamination of Some Abandoned Base Metal and Au-Ag Mines in Korea: A Review," Proceeding of the Korean Society of Groundwater and Environment '99, 51 (1999)
Cope LW, Eng. Min. J., 201, 26 (2000)
De la Vergne JR, "Hard Rock Miners Handbook (CD)," Tempe: McIntosh Redpath Engineering Inc., 2nd edition (2001)
DeVoto RH, McNulty TP, Mining Eng., 52, 19 (2000)
Free ML, Oolman T, Nagpal S, Dahlstrom DA, "Bioleaching of Sulfide Ores - Distinguishing Between Indirect and Direct Mechanisms," In Ross W. Smith and Manoranjan Misra, eds., Mineral Bioprocessing, TMS, Warrendale, PA, 485 (1991)
Garcia C, Ballester A, Gonzalez F, Blazquez ML, Acosta M, Miner. Eng., 9(11), 1127 (1996) 
Hiskey JB, Sanchez VM, Miner. Process. Extractive. Metal. Rev., 15, 65 (1995)
James LP, "Metalliferous Recent Sediments? Mineralogical and Historical Approaches to the Study of Utah Mill Tailings," In H. Doelling, ed. Energy and Mineral Resources of Utah, Utah Geological Association Publication, 18, 59 (1990)
Jones WG, Clauber C, Linge HG, "Fundamental Aspects of Gold Cyanide Adsorption on Activated Carbon," In R. Bhappu and R. Harden, Eds., Gold Forum on Technology and Practices, Littleton, Colorado, Society for Mining, Metallurgy and Exploration, Inc., 278 (1989)
Kawatra SK, Natarajan KA, "Mineral Biotechnology: Microbial Aspects of Mineral Beneficiation, Metal Extraction and Environmental Control," Denver: Society for Mining, Metallurgy and Exploration (2001)
Kral S, Mining Eng., 53, 25 (2001)
Langmuir D, "Aqueous Environmental Chemistry," New Jersey, Prentice-Hall Simon and Shuster, 598 (1997)
Ness V, "Alternatives to Conventional Mixer Settlers," In Randol Cooper Hydrometallurgy Roundtables '99, Denver, Randol International Inc., 29 (1999)
Park ME, Sung KY, Koh YK, Econ. Environ. Geol., 33, 405 (2000)
Prasad S, Pandey BD, Miner. Eng., 11(8), 763 (1998) 
Shuey SA, Eng. Miner. J., 200, 16BB (1999)
Spence JR, "Practical Aspects of Copper Solvent Extraction from Acidic Leach Liquors," SME Annual Meeting, Denver, 19 (1999)
Wells J, "New Developments in Extractive Metallurgical and Mineral Processing, What these may mean for the Definition of "Ore" and "Ore Reserves," P. and D., Assoc. of Canada Short Course Notes, Toronto, 239 (1999)