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Metals in your smartphone have no substitutes

A few centuries ago, there were just a few widely used materials: wood, brick, iron, copper, gold and silver. Today’s material…

Shades of 60 elements that make a computer chip. intelfreepress

A few centuries ago, there were just a few widely used materials: wood, brick, iron, copper, gold and silver. Today’s material diversity is astounding. A chip in your smartphone, for instance, contains 60 different elements. Our lives are so dependent on these materials that a scarcity of a handful of elements could send us back in time by decades.

If we do ever face such scarcity, what can be done? Not a lot, according to Thomas Graedel of Yale University and his colleagues who decided to investigate the materials we rely on. He chose to restrict his analysis to metals and metalloids, which could face more critical constraints because many of them are relatively rare.

The authors’ first task was to make a comprehensive list of uses for these 62 elements. This is a surprisingly difficult task. Much of the modern use of metals happens behind closed doors of corporations, under the veil of trade secrets. Even if we can find out how certain metals are used, it may not always be possible to determine the proportions they are used in. Their compromise was to account for the use of 80% of the material that is made available each year through extraction and recycling.

The next task was to determine if there were any substitutes for these uses. But, as Graedel writes, “the best substitute for a metal in a particular use is not always readily apparent.” Elemental properties are quite unique and substitution will often reduce the performance of the product. But it can be done.

Two examples stand testament to that. In the 1970s, cobalt was commonly used in magnets. When a civil war in Zaire caused scarcity of cobalt, scientists at General Motors and elsewhere were forced to develop magnets that used no cobalt. More recently, a shortage of rhenium, which is used in superalloys for gas turbines, forced General Electric to develop alternatives that use little or no rhenium.

Graedel’s analysis of substitutes involved ploughing through scientific literature and interviewing product designers and material scientists. The results are a sobering reminder of how critical some metals are. On seeing the data, Andrea Sella of University College London said, “This is an important wake up call.”

Which metals have good substitutes and which don't. PNAS

None of the 62 elements have substitutes that perform equally well. And some of those have no substitutes at all (or if there are substitutes, then they are inadequate). They include: rhenium, rhodium, lanthanum, europium, dysprosium, thulium, ytterbium, yttrium, strontium and thallium.

Economists have long assumed that a shortage of anything will promptly lead to the development of suitable substitutes, an attitude fostered in part because there have been successful substitutions in the past, such as the cobalt and rhenium examples. But metals are special, Graedel said: “We have shown that metal substitution is very problematic. Substitution would need to mimic these special properties – a real challenge in many applications.”

“The clarity of Graedel’s thinking is impressive,” said Sella. “No one has analysed metal criticality in such detail.” One of Graedel’s biggest contributions has been developing a visual way of understanding how critical metals are. They created a 3D map, where the three axes represent supply risk, environmental implications and vulnerability to supply restriction.

The Yale analytical framework for determining metal criticality. PNAS

The scarcity of metals came to public attention in 2010 when China suddenly decided to restrict its export of a group of metals called the rare earths. Prices of these metals shot up by as much as five times and caused companies around the world to consider reopening their rare earth mines. This had knock-on effects on the prices of everything from gadgets to wind turbines.

Some comfort may be drawn from the fact that consumptions of some metals can peak. For example, the use of iron has reached saturation in many countries. And, in the US, this seems to have happened for aluminium too. This, however, is the case only for bulk metals. Scarcer metals, even with superior recycling, may never reach saturation.

Apart from China, a handful of countries, including the US, South Africa, Australia, Congo, and Canada, hold the most diverse and largest metal reserves. “A national disaster or extended political turmoil in any of them would significantly ripple throughout the material world in which we live,” said Graedel.

As Sella puts it, Graedel’s measured analysis, published in the Proceedings of the National Academy of Sciences, is a warning of a serious issue. “But he has a thoughtful way of putting it.”

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  1. Ade Jones

    logged in via Facebook

    '“The clarity of Graedel’s thinking is impressive,” said Sella. “No one has analysed metal criticality in such detail.”

    Well, apart from several other reports which have done just this. is an example from 2010 - a report on an EU working group. There are other studies in the literature too - there is a good KTN report on critical raw materials (the title of which escapes me at this precise moment), and Oakdene Hollins have written several good reports on material scarcity.

    A lot of interest in all this - has been building for some years.

  2. garybass

    Education IT Physics

    Many of the rare earths are sourced from meteorite strikes, 27 of the nickel mines in Australia are sourced from such anomalies. Perhaps this goes part way to explaining the urgency/seriousness associated with asteroid mining and moon mining.

    1. Gerard Dean

      Managing Director

      In reply to garybass

      Moon mining!!Spare us please!

      I love it when urban types glimpse the fact that rough, tough miners and millions of litres of diesel fuel are the key to our modern lifestyle.

      Rare earths are now just as critical to human life and progress as the staples like iron, copper, lead , coal and oil.

      Although the above is obvious, the cafe late sipping set turn up their noses at the miners and shippers and smelters and machinists and chemists and scientists and bankers who extract tand process he minerals and energy that brings us the Iphone and lpad and the internet and flying holidays.

      Numbats the lot of them!

    2. garybass

      Education IT Physics

      In reply to Gerard Dean

      And your problem with moon mining?...
      Demonstrably less cost than deep mining once the less than 1km sources are depleted.
      Most existing mines have end of productive life measured in years, a few have decades, though Olympic dam is about 110 years.
      In you look ahead 50 years or so then some serious off planet infrastructure needs to be in place. Most obviously power generation 24/7 directed to where it will be used without the expensive transmission.
      Recall fully one third of the electricity in Australia is used to make big rocks into little rocks and to transport it. ..includes diesel-electric generators and trains.

      This arcticlee was looking ahead to sounces of rare earths, I merely pointed out they are not a renewable resource. With the source originally off planet and a limited number of sites known and no simple means of identifying new sites. The current method, use satellite geo physical maps to identify anomalies, or just look for a crater!

    3. Gerard Dean

      Managing Director

      In reply to garybass

      moon mining will cost billions and use millions of kg of fossil fuels to get a few kg of ore back from the moon.

      you guys should try thinking before typing.

    4. garybass

      Education IT Physics

      In reply to Gerard Dean

      These vehicles do not use fossil fuels! Hydrogen peroxide, oxygen are variants on water. Read a bit more, we are talking about 50-100 years away! There is water on the moon, water in/on asteroids all available for fuels, plenty of solar energy for electricity and high temperature metals separation.

      NASA is launching an asteroid catcher experiment in 2014!

      What price these 'rare earth elements' when there are very few terrestrial sources available. The eay access sand mining is well past the peak of known reserves. Oil is listed as 90 years ((BP 2012 resources survey-exec summary) natural gas 120years, coal several hundred years(!)

      Rare earth elements are called that for a reason, most mines are at sites of meteor impacts...which is where this thread began.
      By going to the source of the 'rare earth elements' in space it will avoid intrusive and extensive digging..500-1500 metres deep