Universiteit Leiden

A Circular Economy of Metals: Towards a Sustainable Societal Metabolism

11 ratings

Metals are present everywhere around us and are one of the major materials upon which our economies are built. Economic development is deeply coupled with the use of metals. During the 20th century, the variety of metal applications in society grew rapidly. In addition to mass applications such as steel in buildings and aluminium in planes, more and more different metals are in use for innovative technologies such as the use of the speciality metal indium in LCD screens. A lot of metals will be needed in the future. It will not be easy to provide them. In particular in emerging economies, but also in industrialised countries, the demand for metals is increasing rapidly. Mining and production activities expand, and with that also the environmental consequences of metal production. In this course, we will explore those consequences and we will also explore options to move towards a more sustainable system of metals production and use. We will focus especially on the options to reach a circular economy for metals: keeping metals in use for a very long time, to avoid having to mine new ones. This course is based on the reports of the Global Metals Flows Group of the International Resource Panel that is part of UN Environment. An important aspect that will come back each week, are the UN Sustainable Development Goals, the SDGs. Those are ambitious goals to measure our progress towards a more sustainable world. We will use the SDGs as a touching stone for the assessment of the metals challenge, as well as the solutions we present in this course to solve that challenge.

From the lesson

Metals in Society

In Week 1, you will be introduced to the world of metals. What are they, what are their properties, what are they used for and how essential are they? We will address the difference between major and minor metals. Major metals are used in large basic applications such as buildings, cars, pipes, cables, bridges, trains and airplanes. Minor metals that are used mostly in all kinds of electronics and in new technologies, for example for wind and solar energy. The amounts used are much smaller. The minor metals have more attention in the news, because of problems with the supply from international trade, and are subject to criticality assessments. The major metals, on the other hand, are even more important, although less in the centre of attention. Without them, society would fall apart. In this course, we will focus mostly on those major metals. We also introduce the Sustainable Development Goals of the United Nations. These SDGs are agreed on by all nations that are part of the UN, and outline goals for the future of the global society. They include goals on economic development, social development, health and the environment and form a powerful framework to judge developments in resource use, including metal use.

Insights from the Life-Cycle of Metals by Prof. dr. Thomas E. Graedel5:37

Life-Cycles of Selected Metals (Part 1)5:27

Life-Cycles of Selected Metals (Part 2)7:15

Metals in the 20th Century9:59

Meet the Instructors

Ester van der Voet
Dr.
Institute of Environmental Sciences

Hello I'm Thom Graedel,

I'm a professor of

Industrial Ecology at Yale University and

a member of the United Nations International resource panel.

One of the tools of Industrial Ecology and thinking about

metals is the life cycle of metals.

Those have been done fairly extensively by a number of groups and

I want to show you examples of some of that work.

First, let me introduce the life cycle in

this circular version of a diagram which is sometimes done in linear fashion,

but this way of approaching the lifecycle gives a sense of the fact

that we really can have circular cycles and circular chains of resources,

and this approach makes that a little more evident.

So in the lower left,

we mined materials from the lithosphere,

smelt them into a concentrate of one kind or another,

refined them into finished metal,

fabricate them into semi-products,

such as rolls of stainless steel,

manufacture them into final goods,

used them for a period of time,

eventually discard them at end of life into

the waste management system where they may be lost to landfill,

they may be lost to other scrap markets and

therefore be nonfunctional as the metal itself

or they may get into an efficient scrap market

where they could come back into the system at various points.

The challenge of life of

material flow analysis is to put numbers on all the arrows in this diagram,

and thus quantify the life cycle.

This is two examples of doing so for

the element nickel in the country China on the left for year 2000.

So you can see that China mines smallish amounts of nickel,

or did in 2005,

moved it forward to stages of purification and processing,

imported some over the dotted line boundary here into

the country and added that to what was coming out of the country based flow,

and in manufacturing them we have a large flow out of

manufacturing into processing and flow into use.

Almost no flow coming out of manufacturing because China,

as a country that has only recently done a lot of technology,

has put material into service in

recent times but has not yet had it go through it's lifecycle and come out of service,

so we have very low flow coming out but

eventually the material that has gone in will be coming out again.

Now, on the right, we see the same diagram for China,

but this time for year 2005, five years later,

and the material flow analysis shows that in that five year period

China's use absolutely exploded from something very small in year 2000,

something quite large in year 2005 flowing through the system,

still importing substantial quantities,

still putting lots of stuff into use,

exporting a bit of manufactured goods.

Again, not very much coming out of use

because things haven't been in use long enough to be ready to come out.

So China is importing lots of scrap to add to

the little bit of scrap it has and thus moving material through

the lifecycle not only within the country but past

the country boundary itself by importing scrap as well as importing raw material.

Material flow analysis doesn't have to be done only at a country level,

if you take all the Asian countries China and Japan,

and Indonesia, and so forth,

you can add them to make an Asian cycle.

You can add Netherlands and Belgium

and the United Kingdom and so forth to make a European cycle,

and so for the rest of the world and make a planetary cycle.

So, these aggregates give you

a much more complete picture than would be available

from looking only at a part of the entire cycle.