Dynamic analysis of copper consumption, in-use stocks and scrap generation in different sectors in the U.S. 1900-2016

More and more attention is paid to application of material flow accounting for the sustainability of resource management. This paper evaluates the dynamics stocks and flows associated with the U.S. copper industry based on historical data of copper consumption during1900-2016. This paper shows the current in-use stocks and predicts the amount of scrap generation until 2031 of different consumption scenarios. During1900-2016, about 60% of consumed copper transformed to scrap, the rest still existed in in-use stocks. The change of copper consumption during 2016-2031 has little effect on the amount of scrap generation in 2031. For sectors, building construction is the largest consumer of copper, with an average of 37% of total consumption. But scrap generated from building construction is only 16,800 Gg, far less than the 33,900 Gg generated from electric and electronic products. This is due to the generally long-life expectancy of building construction. Besides, the maximum amount of in-use stocks is 74,400 Gg in the calculation period, 67% (about 49,700 Gg) of which is from building construction. Several recycling indicators defined from different perspectives also have been measured. All recycling indicators in the U.S. are higher than the global average. However, compared to the considerable amount of scrap generation, recycled copper for domestic consumption is very small, only accounting for 8.1% in the past decades. This is because of large amount of export scrap and high recovery costs.