By Siyi Liu and Dominique Patton

BEIJING (Reuters) -China, the world’s top processor of rare earths, on Thursday banned the export of technology to extract and separate the strategic metals, as it overhauled a list of technologies deemed key to national security.

The commerce ministry sought public opinion last December on the potential move to add the technology to its “Catalogue of Technologies Prohibited and Restricted from Export”.

It also banned the export of production technology for rare earth metals and alloy materials as well as technology to prepare some rare earth magnets.

The move comes as Europe and the United States scramble to wean themselves off rare earths from China, which accounts for 90% of global refined output.

Rare earths are a group of 17 metals used to make magnets for use in electric vehicles, wind turbines and other electronics.

China has mastered the solvent extraction process to refine the strategic minerals, which Western rare earth companies have struggled to deploy due to technical complexities and pollution concerns.