Handbook of Environmental Engineering

22Waste Reduction in Metals Manufacturing

Carl C. Nesbitt

Department of Chemical Engineering, Michigan Technological University, Houghton, MI, USA

The metals industry is one of the most important sectors of the world economy. In the United States alone, the consumption of steel products approaches 120 million tons each year, while the consumption of aluminum averages 6.5 million tons per year and the copper consumption averages over 4 million tons each year. The production of metals comes from primarily two routes – production of metal from mineral resources or recycle of spent metal products. For example, on average approximately 67 million tons of steel are produced from recycled scrap (~55%), 2.9 million tons of aluminum were made from old and new scrap (~52%), and 1.3 million tons of copper were produced from scrap (~30%) in the United States each year. Almost 75% of the lead used in the United States is from secondary sources and recycling. Recycling metals directly saves our society by reducing the amount of waste generated, and energy consumed, to produce new metal products. Improving economies of individual nations typically are preceded by an increased demand for metals and metal products. An increased consumption of construction products (especially steel and copper) is one of the leading indicators that an individual country’s economy is growing – as has occurred in the China and Asia markets.

The mining of ores is still the primary means of producing new metals ...