Secondary Zinc Reserves of Nations

As an outcome of global growth of economies and populations during recent decades, global trends of metal consumption have increased rapidly, creating vast quantities of metallic materials accumulated in human society. Those... [ view full abstract ]

As an outcome of global growth of economies and populations during recent decades, global trends of metal consumption have increased rapidly, creating vast quantities of metallic materials accumulated in human society. Those anthropogenic stocks of metals constitute reserves of secondary resources. From the perspective of sustainable use of resources, secondary reserves of metals in society are expected to become fundamentally important for meeting the growing demand, thereby lessening reliance on limited primary metal reserves in the lithosphere. Wider use of secondary reserves is also expected to contribute to energy savings and emissions reduction in metal production processes.

Using a classification framework of secondary resources, this study defined and quantified the reserves of secondary zinc in different final destinations and the profitability levels for reutilization in major countries. The secondary reserve ratio, the fraction of anthropogenic zinc stocks that are technically and economically feasible for recovery, has been determined. Zinc use in the five sectors of construction, electrical and electronic products, industrial machinery and equipment, transportation, and consumer and general products were considered. Preliminary results indicate that the United States possesses the largest secondary zinc reserves, as well as the zinc stocks in use, followed in order by China, Japan, and Germany. The quantity of secondary zinc reserves in the United States has exceeded its primary zinc reserves in the lithosphere.

Quantitative assessment of secondary reserves and resources provides new knowledge that can be useful for establishing policies and strategies related to urban mining and recycling systems.