The Legacy of American Copper Smelting: Industrial Heritage versus Environmental Policy

Chapter 2. The American System: A Technological Context

Chapter 2 The American System: A Technological Context The seriously degraded American copper mining and smelting landscapes that required extensive EPA involvement in the late twentieth century resulted from the ever-increasing and nationally significant role that technology played both in smelting copper ores and in escalating demands for the metal. Were it not for copper’s high conductivity, the rapid spread of electricity across the North American continent, and the continued development of applications that produced light, produced or used electromagnetic power, or enabled long-range telecommunications, there may have never been such a high demand for the red metal, and copper companies would have never needed to develop technological systems to successfully process ores containing as little as 0.5% copper. Although the three districts discussed in this book generally did not work ores less than 2% rich, many of the systems they implemented made even poorer ores economically viable. But processing such lean ores left considerable amounts of waste and extensive destruction on the landscape, including tailings from the presmelting concentrating of the ores, slag from smelting and refining, gas damage from roasting and smelting, and a host of toxic materials from the ores themselves and from their processing. Each of the districts also operated for more than a century, leaving a considerable environmental legacy with which their postmining communities would have to contend. But the very technologies at the root of such environmental destruction, however, helped propel American technological and economic ascendancy, thus leading to sites and landscapes of significant historic value. The American System 16 This chapter will explore the historic context of copper smelting in the United States, and how this industry gave rise to three historically important areas, whose contributions to American history rightly deserve commemoration and recognition alongside efforts to remediate their landscapes . Specifically, this chapter will examine the broad historical and technological trends in American smelting, which led to the development of successful systems in the mining districts of Michigan, Tennessee, and Montana, and the evolutionary technological changes that were required to maintain profitability as ore quality diminished. Next, it will look more closely at the three individual regions chronologically and at the specific smelting technologies they used to exploit their particular copper deposits. The chapter will then introduce the environmental histories and consequences of their smelting technologies, which led to direct federal interaction either under Superfund or federally monitored remediation. Smelting USA There never was a truly American system of copper smelting. After the decline of British copper production and a very short period of dominance by Chile, the United States became the world’s largest copper producer and consumer, and maintained that lead for nearly a century. Two primary factors drove this ascendancy: the discovery of significant American copper deposits and the adoption and modification of existing European technologies to fit the new deposits. The “Americanization” of the smelting industry was further propelled by the persistent need to overcome high labor costs with mechanization and by the general growth of large-scale corporations using available capital to foster technological improvements and to create significant economies of scale. The scale of these operations became increasingly important as rich copper deposits declined and very large deposits of exceptionally lean ores remained or were discovered. These lean ore bodies often contained as little as 0.5% copper and required ever-greater technological sophistication to eliminate up to 99.5% waste and further reduce labor and processing costs to make the extraction and production of copper from such lean ores economically viable. In fact, complex copper smelting would only succeed when enough capital existed to invest heavily in technologies to adapt those The American System 17 processes to the local geology. Both of these conditions coalesced in the late nineteenth century, as very large American copper deposits opened, demand significantly increased, and, to disseminate information and encourage innovation, a technical community developed from expanding mining colleges, mining journals, and industry-wide conferences. While technological improvements led to ever-increasing production, few engineers at the time considered the lasting environmental effects of successful metallurgical applications on such lean ores. But the elimination of such a high proportion of gangue, or waste rock, on such a massive scale posed not simply a short-term disposal problem for mining companies, but also a significant long-term pollution problem for the United States. By the mid-nineteenth century, the Welsh system in Britain had evolved...