The crisis we’re now facing with the worldwide shortage of rare earth metals is a case of history repeating itself. That was the message delivered by Critical Materials Institute Director Alex King during a Lunch and Learn session held Aug. 20.
King provided a brief history lesson on the Bronze Age as a backdrop to his talk on critical materials and how the CMI plans to address those problems. Bronze, a combination of tin and copper, was a major advancement for early civilization for use in tools and weapons. It was harder and held a much better edge than plain copper implements and it didn’t corrode.
This technological advance also led to expanded trade throughout the Middle East and Africa which also brought about even wider spread bronze use. As demand increased, the primary source of copper in Cyprus dried up and trade subsequently collapsed along with the civilizations dependent on it.
Archeologists and anthropologists have uncovered a “gap” of about 200 years between this collapse in about 1200 B.C. and the rise of the Iron Age. In that gap, bronze was recycled, emerging power Egypt found alternative copper sources in Africa and improved processing led to the development of iron as a substitute material.
Shift to present day and the scenario is similar. New technologies, many of them energy-related, have developed around rare-earth materials, but shortages of those materials are impacting the effectiveness and/or implementation of those technologies. And demand is growing because on a worldwide basis, the percentage of people considered to be middleclass – those with disposable income – is growing.
For example, King said the transition to high-output T5 fluorescent lamps has been delayed by two years because manufacturers claim that they can’t find enough europium and terbium for the phosphors – the coatings inside the tubes that glow and give off the light. A similar problem is affecting the wind generation industry.
“Most wind turbines use a mechanical gearbox to spin the generators fast enough to generate electricity,” King said. “The problem with this design is that the gearbox can literally explode; the maintenance costs are high and so is the failure rate.”
Direct-drive designs already exist that use only the turbine shaft to drive the generator motor, eliminating the gearbox and the associated problems. But these generator motors require much larger neodymium-based magnets and it’s just not feasible to use that much neodymium and dysprosium.
“There are 33,000 commercial wind turbines today and only 233 of them are direct-drive units,” he said.
Fortunately, it won’t take 200 years to come up with a solution like it did for the Bronze Age, but it still won’t happen overnight.
“If we have a known source of raw material, it still takes at least 10 years to develop a mine to extract the material,” King said.
To deploy a substitute material that already exists, industry still needs an average of four years to make the switch. It takes time to use up existing inventory, do the necessary retooling and establish a new supply chain. And to develop and deploy a NEW substitute material it takes an average of 18 years. The Critical Materials Institute will address this interim period and help ease the transition.
“CMI’s mission is to eliminate materials criticality as an impediment to the commercialization of clean energy technologies for today and tomorrow,” King said. It will do this with a “Three-D” approach of diversifying supply, development of substitutes and driving reuse, recycling and efficient use of materials in manufacturing.
The two guiding principles are to produce more and use less. While that may sound simple, it is the focus for the initial 35 projects that will have the involvement of all 18 CMI partner institutions. This includes making sure the project can make an impact at a key point in the material’s lifecycle and having a commercialization plan in place on day one. And if conditions change, such as increased supply or decreased demand for a particular material, related projects will be terminated and resources shifted to new areas.
To illustrate the approach, King highlighted efforts underway to address the rare-earth phosphor shortage for fluorescent lamps.
On the supply side, phosphate used primarily for fertilizer, is one of the most common and heavily mined materials in the world. While the concentration of rare-earths in phosphate rock is very small (.01 to 0.1 percent), it represents a worthwhile, untapped source simply because of the huge amounts of phosphate being processed – about 220 million tons annually in the world.
CMI is investigating ways to extract those rare earths at different points in the phosphate production process without adding steps or significant cost or time.
On the recycling front, fluorescent tubes and compact fluorescent bulbs are already collected for recycling as a way to keep mercury from being released into the environment. CMI will assess the physical and chemical character of phosphor from such lamps and potential processes for separating rare-earth oxides from this source.
A variety of factors from changing markets, inadequate forecasting tools, and a lack of control at key points in the supply all present challenges.
"Materials can go critical on very short notice," King said. "We can't always see crises coming."
~ by Kerry Gibson