An American Child's Future.

With decreasing concentrations of many minerals thus requiring more energy to mine and process. With the decreasing ERoEI of fossil fuels primarily petroleum also requires more energy to obtain. With many minerals and other materials requiring high temperatures (2000°C) to process, this will be an interesting future.

This paper quantifies, on a global level, the relationship between ore grade and energy intensity. With the case of copper, the study has shown that the average copper ore grade is decreasing over time, while the energy consumption and the total material production in the mine increases. Analyzing only copper mines, the average ore grade has decreased approximately by 25% in just ten years. In that same period, the total energy consumption has increased at a higher rate than production (46% energy increase over 30% production increase).

“Decreasing Ore Grades in Global Metallic Mining: 

A Theoretical Issue or a Global Reality?”

Guiomar Calvo 1,*, Gavin Mudd 2, Alicia Valero 1 and Antonio Valero

http://www.mdpi.com/2079-9276/5/4/36/htm

Resources 2016, 5(4), 36; doi:10.3390/resources5040036

Things may change?

REE = Rare Earth Elements