Graedel, Harper, “A Tale of Three Metals” in E-Waste Management;
From Waste to Resource
Introduction
This review focuses on the issue of resource sustainability, highlighting three important
metal elements - copper, tungsten and indium with quite different spectra of use, reuse and
loss. Copper is essential in its ability to conduct electricity and heat, making it the metal of
choice for power transmission and heat transfer. Tungsten has the highest melting point for
metal (3,422 Degrees) which make it vitally important for use in metalworking and aircraft
construction. Indium is a by-product of zinc ores and is used for display services such as
LCDs and touchscreens.
What are the three most important findings you can take from this paper?

20 years ago, a computer chip contained 11 different elements, today they contain
over 60, resulting in faster speeds and capabilities. This highlights the need to
maintain such elements at a sustainable rate.

Over Half-century ago, a dozen or so elements were sufficient to satisfy most
industrial uses. Today, modern technology requires essentially the whole periodic
table to perform the specialized functions that enable and enhance our lives.

The resource occurrence of tungsten is heavily weighted toward China, which could
present a geopolitical challenge if resources elsewhere are depleted over time.
Why are coppers prospects relatively satisfactory?

Copper is recycled more efficiently than other metals because of its use in
conducting electricity and heat.

The typical recycled content is roughly 20-30%, and the end-of-life (EoL) recycling
rate is estimated to be 40-50%.

Since Copper has a long-term supply potential and if the predictions of world
population at nine billion by 2050 are correct, the suspected demand for copper
meets the estimated upper limit of its resources predicted. The resource magnitudes
that have been advanced are approximately 1.6 Pg Cu while the total requirement by
2050 will be approximately 1.4 Pg Cu.
Why is there more concern about indium?

There is no information available on the geological stocks of indium.

Indium is an example of a by-product element that is wholly dependent on the
mining of zinc ores and its abundance in those ores is almost unknown.

The countries with the largest quantities of indium are presumably the countries
with the largest geological zinc stocks such as China and the United States.

Recycling rates worldwide are estimated to be between 25% and 50%, but Indiums
end of life (EoL) recycling rate is less than 1%.

This uncertainty surrounding the resource availability of indium presents a problem
for future sustainability.
Why is this potentially a problem for the electronics sector?

Copper resources seem to be adequate at present, but problems could arise if there
is a sudden “increase in demand as global wealth rises”. Substitutes are available for
its many uses, but come at a sacrifice in performance.

Tungsten is an important element because of its inherent hardness and this is why it
is essential in mining and metalworking. So no adequate substitutes are available.
Since China holds the most reserves of tungsten, if China decides to restrict exports
for domestic use or geopolitical reasons, this could put the remaining global reserve
bases “under substantial pressure”.

Since Indium is a by-product of Zinc, “its abundance in those ores is almost
unknown”. As high technology areas such as displays and solar panels are expanding
rapidly, “short-term supply disruptions have already started”.
Name: Vincent O’Connell
ID: 10097171