Criticality Of Metals – Approaching Difficulties
In an effort to quantify the criticality of the 62 metals on the Period Table of Elements, a group of Yale researchers has published a new paper providing key insights into how extracting the metals will fare in coming decades, with regard to the environmental cost and their role in technology.
The paper outlines that many of the metals traditionally used in manufacturing, like zinc, copper and aluminium, remain essential and show no signs of being vulnerable, but other metals, like those used in smartphones and medical imaging, may be harder to obtain in decades approaching.
The study is the first peer-reviewed assessment of the criticality of the world’s metals and metalloids.
Professor of Industrial Ecology at the Yale School of Forestry and Environmental Studies in the US and lead researcher Thomas Graedel said the metals we’ve been using for a long time probably won’t be at risk of disappearing.
“We’ve been using them for a long time because they’re pretty abundant and they are generally widespread geographically,” Professor Graedel said.
“But some metals that have become deployed for technology only in the last 10 or 20 years are available almost entirely as byproducts. You can’t mine specifically for them; they often exist in small quantities and are used for specialty purposes. And they don’t have any decent substitutes.”‘
Published in the Proceedings of the National Academy of Sciences, the paper encapsulates the Yale group’s five-year assessment of the criticality of the planet’s metal resources in the face of rising global demand and the increasing complexity of modern products.
According to an article published in Science Daily, researchers say that “criticality depends not only on geological abundance. Other important factors include the potential for finding effective alternatives in production processes, the degree to which ore deposits are geopolitically concentrated, the state of mining technology, regulatory oversight, geopolitical initiatives, regional instabilities, and economic policies”.
When assessing the state of all metals, the researchers developed a methodology that characterizes criticality in three areas: supply risk, environmental implications, and vulnerability to human-imposed supply restrictions.
It was discovered that supply limits for many of the metals, like gallium and selenium, which are critical to the emerging electronics sector, are the result of supply risks. For metals like chromium and niobium for steel alloying, and other elements used high temperature allows, the biggest vulnerabilities are associated with supply restrictions.
As mentioned, there a number of factors that contribute to the criticality challenges, including geopolitical concentration, lack of available substitutes, and political instability in countries like the Democratic Republic of the Congo, where a significant portion of tantalum, widely used in electronics, comes from.
Another issue researchers regarded was the recycling rates and how different industries have been able to use “non-virgin” sourced materials. Some metals, like lead, are recycled at a high rate since they are usually used in bulk. At the other end of the spectrum are some of the metals used in electronics, which are considerably more difficult to recycle due to the design in which they are built into.
“I think these results should send a message to product designers to spend more time thinking about what happens after their products are no longer being used,” Professor Graedel said.
“So much of what makes the recycling of these materials difficult is their design. It seems as if it’s time to think a little bit more about the end of these beautiful products.”