The contemporary Latin American and Caribbean copper cycle: 1 year stocks and flows

摘要

Substance flow cycles can provide a picture of resource uses and losses through a geographic region, thus allowing the evaluation of approaches to regional resource management and the estimation of gross environmental impacts. This paper traces the flow of copper as it enters and leaves the Latin American and the Caribbean (LAC) economy over 1 year. A regional material flow model was developed to estimate patterns of copper use in the early 1990s throughout LAC. Material balance calculations were used to determine copper flows, including the amount of metal that enters use in society and in waste repositories. A database and modeling tool that records temporal and spatial boundary conditions and data quality was developed for continental substance flow analysis. The result provides a numerical accounting of copper from ore, to product, to potential secondary resource. The modeling also shows how materials are transformed and processed, recovered, and stored at each stage in the life cycle of copper. LAC is a significant global producer of primary copper through its mining, smelting, and refining operations; about three-fourths of this output is exported from the continent. The remainder is fabricated within LAC and enters the societal use reservoir in infrastructure, buildings, industry, private households, and other uses. Chile is the dominant producer and exporter of copper in the region. The majority of copper in finished products is contained in pure form (70%, 212 Gg out of 305 Gg), the remainder in alloy form. Copper from post-consumer waste is roughly 10 times smaller than tailings and slag waste. This research shows that there is a significant stock of copper both in use and hibernating in retired electronic products. There is also an informal recycling system and secondary market that is not quantified, but estimated to be up to 80% of recovered post-consumer copper.