Substance flow analysis of zinc in China

A material stock and flow (STAF) model was constructed to track the pathway of zinc in China, 2006, for the study of the industrial metabolism of a certain metal within a regional level. The primary flows of zinc include production, fabrication and manufacturing, use, and waste management. This paper traces the major flows of zinc from ore, to product, to potential secondary resource as it moves through the China's economy over 1 year, and inventory data, and mass balance equations were used to determine the quantity of flows. The domestic ore produced was 3248.3 Gg and output of refined lead ingot was 3162.7 Gg in 2006. It was calculated that, in the production and manufacture and fabrication stage, the self-supply efficiency of zinc raw materials in 2006 is 87.58% and 94.92%, respectively. The results reveal that China has richer zinc raw resources. But only about 3.68% and 9.06% of the discarded zinc in the two stages were recycled, respectively. While zinc's residence time can be high for many of its applications in the building and construction sector, since the majority of zinc is used as an anti-corrosion coating, there are dissipative losses occurring during the lifetime of products and infrastructure containing zinc. This study and others suggest that zinc losses to the environment are significant in magnitude, and their impacts should be evaluated over time and at various spatial scales. In addition, the results of this study and other element and material flow analyses can help guide resource managers, environmental policy makers, and environmental scientists in their efforts to increase material recovery and recycling, address resource sustainability, and ameliorate environmental problems.