Manufacturing Bits: Dec. 6

China’s rare earth land grab; separation process; neodymium.


China’s rare earth power play
Rare earth elements (REEs) are back in the news.

China, the world’s largest supplier of rare earths, plans to combine three domestic vendors to create a large state-owned company with a nearly 70% share of the REE market, according to reports from Nikkei and others.

In 2020, China in total accounted for 85% of global production of refined REEs, according to Wood Mackenzie, a research firm. REEs are chemical elements found in the Earth’s crust. These elements, which are critical, are used in cars, consumer electronics, computers, communications, clean energy and defense systems.

Meanwhile, the entities involved in China’s consolidation efforts include China Minmetals Corp., China Aluminum Corp. and the government of Ganzhou City in Jiangxi Province, according to the reports. China in turn plans to consolidate these entities into a new state-run firm called China Rare Earth Group., according to the Wall Street Journal.

The move is designed to strengthen China’s control over the REE market. In response, the United States is developing its rare earth industry to reduce its reliance here.

REEs, also known as lanthanides, are a group of 15 elements that can be separated into two categories. “Light REEs include lanthanum (La), cerium (Ce), praseodymium (Pr) and neodymium (Nd),” said Wood Mackenzie analysts Ross Embleton and David Merriman. “Heavy REEs include the suite of lanthanides ranging from samarium (Sm) to lutetium (Lu) and plus yttrium (Y).”

REEs are critical. “They’re used in the electrical and electronic industries, the oil industry, aviation and the manufacture of glass and lasers, among other things. However, their use in magnet technologies, in particular, provide an opportunity to improve the efficiency of and/or miniaturize critical electronic components. The development of high strength rare earth permanent magnets has proven crucial to the development of certain new energy technologies,” said Embleton and Merriman.

“REEs have numerous applications, being used in specialty ceramics, fluorescent lighting and PET scanners,” they added. “New energy technologies, specifically, wind turbines and electric vehicle (EV) drivetrains, have spurred demand for rare earth permanent magnets, with neodymium (NdFeB) magnets commanding the largest market share.”

Separating REEs
The U.S. Department of Energy (DOE) recently announced $30 million in funding for 13 national lab and university-led research projects to develop new technologies that will help secure the supply of critical materials in the United States. These materials include cobalt for electric vehicles batteries, neodymium for windmills and electronics, and platinum for emissions control and fuel production technologies.

In one project, Ames Laboratory has been awarded up to $2.89 million by the DOE to research a new separation process for rare earths. Operated by Iowa State University, Ames Laboratory is one of several national laboratories in the U.S. Department of Energy.

The project will investigate the fundamental mechanisms of rare earth separations using an existing process. It involves a separation process, which takes place in ionic adsorption clays. “Ionic adsorption clays adsorb the heavier rare earths that come from the weathering of rocks by water, and hang on to them. Lighter and more soluble rare earths pass through the clays,” according to Ames Laboratory.

Adsorption and absorption are different. Absorption involves a liquid, which is soaked up into an object. “Adsorption refers to individual molecules, atoms or ions gathering on surfaces,” according to ChemBAM, a research site.

The work in Ames’ rare earth project utilized analytical electron microscopy imaging and characterization capabilities. The goal is to understand the dynamics of adsorption and mechanisms of retention of rare earth elements in natural micas and synthetic layered materials.

“One of the problems is the geological time scale,” said Tanya Prozorov, an Ames Laboratory scientist. “In nature, this process can take thousands of years and yield unpredictable adsorption of rare earths. We want to understand how this process works, learn to control it, and then replicate it as a faster, more efficient, and tunable process for adsorbing and separating rare earths using layered synthetic clays.”

Finding neodymium
Pennsylvania State University has developed a new process to separate and recycle neodymium using plant cellulose.

Neodymium, one of several rare earth elements, can be combined with iron and boron to make a strong permanent magnet.

Neodymium-iron-boron magnets are used in the motors of electric and hybrid vehicles. For example, the Toyota Prius contains some 1 kg of neodymium in its motor. Neodymium magnets are also used in wind turbines, aerospace and other products, according to the American Chemical Society.

Neodymium and other rare earths are found in the Earth’s crust, but these deposits are relatively sparse. Thus, the industry has turned to recycling to obtain these elements in cars and other products. But separating the valuable elements from other minerals is difficult.

In response, Penn State has developed a new process to separate and recycle neodymium. The process involves so-called hairy cellulose nanocrystals, which are nanoparticles derived from cellulose.

In Penn State’s process, the nanocrystals bind to neodymium ions, separating them from other ions, according to researchers. “To do this, the researchers negatively charged the hairy layers of the nanoparticles in order to attract and bind with the positively charged neodymium ions, resulting in particle aggregation into larger pieces that can then be effectively recycled and reused,” according to Penn State researchers.

“The process is effective in its removal capacity, selectivity and in its speed,” said Amir Sheikhi, assistant professor of chemical engineering and biomedical engineering at Penn State. “It can separate neodymium in seconds by selectively removing the element from some of the tested impurities.”

“Using cellulose as the main agent is a sustainable, cost-effective, clean solution. Using this process, the United States will be able to compete with other giants like China to recover rare earth materials and independently produce them,” Sheikhi said. “This contribution to rare earth recycling will have a strategic and economically-viable impact on several industries. The more neodymium we recycle, the more we can manufacture electric and hybrid vehicles and wind turbines, leading to less strain on the environment.”

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