Let's recall the metals challenge as it was explained two weeks ago.
It revolves around two questions:
Do we have access to sufficient metals to fulfill the needs of
the world and are
the environmental impacts related to mental production and use acceptable.
We have seen that for both issues,
we may run into constraints in the future and in some cases already now.
The question for this week is, how can we reduce these challenging issues.
Basically, there are two ways of doing this.
In the first place,
we can take a step by step approach where we look to
the life-cycle of the metals and see how in each step we can make improvements.
This is the topic of this week, Week four,
and we will have lectures on such improvement options from experts in the field.
In the second place,
we can take a more integrated approach, where we look at the metals life-cycle as
a system and see how we can make improvements from that wider system's perspective.
This we will explore next week.
So, let's look at the metals life-cycle,
using the figure of the Yale STAF project we've seen earlier.
We have the mining and refining of metals.
Then we have to production of compound materials and the manufacturing of products.
Then we have to use of these products in households and companies.
And finally, there is a waste management after the products have ended their useful life.
All of these stages are connected to energy use and all of them have waste and emissions.
Over the whole lifecycle,
losses of metals occur and after discarding all the metals are lost anyway,
unless something is done about it.
And there are possibilities to do so over the whole lifecycle.
To start with mining and refining,
the aim of this life-cycle stage is to produce new metals and from our point of view,
this should be done by using as little energy as
possible and create as little waste and emissions as possible.
That means the focus is actually on the processes themselves.
Technological options to increase the efficiency of those processes.
We have seen the process efficiency of mining and refining has improved significantly
over the last century and the end of that is not yet in sight.
The waste streams that are unavoidable should be stored safely.
So they do not contaminate the surrounding environment.
After mine closure, there are possibilities for remediation.
So the site is restored as much as possible.
These options exist, and they are practiced.
Although in many places,
they are not or not yet,
at least so we hope.
In this stage of material production,
a lot of improvements can be made by a more careful material design.
Professor Eric Hofman will go into the possibilities of designing materials
with much less additives which would really improve the possibilities for recycling.
In the stage of product manufacturing,
a design for recycling or designed for the environment can increase
the options we have for repair, remanufacturing, or recycling.
And so keep the materials in use for a longer time.
It's also possible to try and design products using less materials altogether.
Professor Conny Bakker in her lecture will tell
us about the possibilities that exist there.
In the use phase,
the technological options for improvement are limited.
That doesn't mean that nothing can be done.
Consumers are powerful actors in the supply chain.
Their demand drives the supply chain,
and they can take care to keep products in use for a longer time by deciding to
repair instead of throwing the products away or by postponing replacements for some time.
Technological options to keep the material and products
in use for a longer time do exist.
Repair, refurbishing and remanufacturing do just that.
Professor Nabil Nasr a well-known expert on
remanufacturing will tell us about these options.
Finally, there is a waste management.
The main option here,
at least for metals,
is to recycle them instead of throwing them away.
Professor Thomas Graedel talks about recycling.
So, this is a full week.
But we are lucky to have experts from all over the world to inform us.