Production residues in copper technological cycles

Calculations by a top-down method based on copper output and the efficiency of milling and smelting show that in making of 101 x 10(3) kt of metal from ore in the US 12.9 x 10(6) kt of tailings and 212 x 10(3) kt of slag containing 16.5 x 10(3) kt of copper were placed in wastes retained at mill and smelter sites through the 20th century in the US. The lost copper is 14% of the metal content of the ore processed, and its recovery would supply nearly 10 years of copper demand in the US at present consumption rates. Comparison with end-of-life copper in the different use categories shows that mill and smelter residues are the single largest component of the copper waste budget. for the US. Because state-of-the-art copper production techniques were promptly adopted worldwide through the 20th century, the top-down method can be used to determine milling and smelting losses in the global anthropogenic copper cycle. (C) 2002 Elsevier Science B.V. All rights reserved.