SX-EW copper and the technology cycle
Fig. 1 summarizes the production of US based mined copper (SX-EW and otherwise) from 1970 to 2000. This figure can be divided into three main periods. The first period, 1970–1984, features irregular, but overall declining, production in US mined copper from a high of 1.56 million tonnes 3 in 1970 to a low of 1.04 million tonnes in 1983 (Table 1).