Estimation of In-Use Stock of Copper in China, Korea and Taiwan

Recently, material stock accounting has been of interests to investigate the potentials of metal scrap recovery in designated areas. There are two approaches, a top-down approach and a bottom-up approach, for estimating the in-use stock of materials. Top-down approach uses time-series data of consumption and trade of materials and products' life time distributions, whereas bottom-up approach uses the numbers of product units in the designated area and its material use intensities. In this paper, the copper stock in China, Korea and Taiwan were divided into 7 end-uses and estimated by the top-down approach and/or bottom-up approach. The total copper stocks in 2005 were estimated as 25,000 Gg in China, 4,000 Gg in Korea and 2,600 Gg in Taiwan, whereas the ones in 1990 were 4,800 Gg in China, 900 Gg in Korea and 950 Gg in Taiwan. These results show that copper stock in these 3 countries has increased to almost 5 times in the past 15 years.