Urban Mining A Contribution to Reindustrializing the City

Megacities can produce sufficient amounts of secondary resources for large-scale production of raw materials by urban mining, and cities are always in need of energy. Thus, combining recycling plants for metals such as iron, aluminum, and copper in cities with utilization of waste energy from such plants to fuel the city (heating and cooling, electricity) seems an attractive option for improving the sustainability of cities. Today’s most advanced societies are serviceoriented economies. The main resources of such societies are knowledge and information created by and embedded in people and institutions. Classical resources, such as materials, energy, and land, are of less value for service-oriented societies. Nevertheless, even if one acknowledges the primary role of intellectual resources, material resources are still the backbone of all societies. We cannot pursue our daily activities without the provision of cement, steel, aluminum, cellulose, polyethylene, linear alky benzene sulfonates, and many other materials. Given the high volatility of resource prices and the still heavy pollution of primary production, recycling becomes mandatory. A new approach toward recycling is “urban mining.” The term denotes the systematic reuse of anthropogenic materials from urban areas. It is based on the fact that large stocks of materials are incorporated into cities, in particular in buildings and infrastructure but also in landfills. These stocks represent a large resource potential that will eventually—at the end of the product lifetime—become available for reuse. There is no general definition for urban mining yet: Whereas some researchers use