Concerns that rare earth minerals could soon be at the center or trade war between the United States and China escalated when Chinese state media implied that China could restrict sales of the minerals to the United States.

China has long dominated the rare earth sector and according to estimates from the U.S. Geological Survey still controls about 80 percent of the world’s processing capability of the minerals used in a variety of high tech applications.

Efforts to build rare earth processing plants in the United States are still in the early stages and lack unified support from Congress and the administration of U.S. President Donald Trump.

Reuters reported that at least three U.S.-based companies have rare earth processing plants under construction or in the planning stages.
The Mountain Pass Mine in California, a mine with a long history of opening and closing, is on pace to return to production and will become the sole operating rare earth processor in the United States. It is set to produce about 5 kt/a (5,500 st) of two popular types of rare earth, according to a source familiar with the matter.

The other two are not expected to open until 2022 at the earliest.

"It would be important for the U.S., and the world, to have these minerals processed in a place outside of China," said Jon Blumenthal, chief executive of privately-held Blue Line Corp, which earlier this month signed a memorandum of understanding to build a rare earth processing facility in Texas with Australian-based Lynas Corp.

Blumenthal declined to say how much the project will cost or forecast its processing capability. Blue Line processes small-batch rare earths for use in the oil refining industry currently, and the Lynas venture would be its largest project to date, though Blumenthal said it would be at least three years before it would open.

Meanwhile, Texas Mineral Resources Corp is pushing to develop the Round Top rare earth deposit in a remote corner of the state's western edge. The project, which will cost more than $300 million to develop, would involve an on-site mine and processing facility that would annually process about 7.3 Mt (8 million st) of ore and produce about 3,325 t (3,665 st) of rare earths.

The company has seen its stock jump 68% in the past month, although the Round Top facility is not slated to open until 2022 at the earliest.
The United States has excluded Chinese rare earth imports from recent tariff hikes, along with some other critical Chinese minerals.

China, however, has raised tariffs on imports of U.S. rare earth metal ores from 10% to 25%, making it less economical to process the material in China.

Privately-held MP Materials, which owns the Mountain Pass mine and ships the roughly 50,000 tonnes of rare earth concentrate it extracts each year from California to China for processing, has criticized the "unilateral tariffs."