BEIJING (Reuters) - China's exports of rare earth magnets to the United States rose more than 20% in May from the previous month to their highest since at least 2016, data released by the General Administration of Customs showed on Tuesday, as Beijing considers restricting shipments as part of a long-running trade row.
Rare earth magnets are widely used in medicine, consumer electronics and the military, although U.S. President Donald Trump in August last year signed a defense policy bill banning the purchase of rare earth magnets from China for the military in the 2019 fiscal year.
The most widely used type, prized for their strength, are those made with neodymium, one of the 17 rare earth elements.
Exports to the United States of permanent rare earth magnets, or material that will be turned into permanent magnets, came in at 430,961 kg, or around 431 tonnes last month, the customs data showed. That was up 21.5% from April and up 4.4% from May 2018.
It was also the highest monthly export figure on customs database records going back to January 2017.
In 2018, China's exports of rare earth magnets to the United States were worth a total 1.325 billion yuan ($192.7 million), the customs data showed.
Chinese President Xi Jinping visited a rare earth magnet plant in Jiangxi province on May 20 this year, sparking speculation that China's dominance of global rare earth production could be used as a weapon in the Sino-U.S. trade war.
Beijing has since said it is considering strengthening controls on rare earth exports.
Ryan Castilloux, managing director of consultancy Adamas Intelligence, said big fluctuations in the export numbers were normal, however. "I wouldn't doubt that some of it is stockpiling but there's nothing definitive there to point us in that direction," he said.
Another key rare earth for the United States is lanthanum, which is used in the oil refining industry. Exports of lanthanum oxide stood at 534 tonnes in May, the customs data showed. That was up 59.4% from April and up 14.1% year-on-year.
Exports of lanthanum carbonate, meanwhile, were at 400.1 tonnes, down 64.3% from April but more than double the 197 tonnes exported in May 2018.
China's overall rare earth exports, which can fluctuate wildly, fell by 16% in May from the previous month, according to data released earlier in June.