China said it was changing its production rules -- which will idle a third of the country's 23 mines and about half of its 99 smelting facilities, to improve the environment and consolidate the industry, CNN reported Wednesday.
Rare earths are 17 minerals having magnetic and conductive properties that used in electronic devices such as flat-screen televisions, smart phones, hybrid cars and weapons. Nearly all of the rare earths are from China.
The production cut threatens to agitate trade tensions between China and the United States, observers said. The United States, Japan and the European Union have complained to the World Trade Organization that China's export restrictions on rare earths violate international trade rules.
The new regulations are designed to boost the minimum annual output at mines to 20,000 metric tons and 2,000 tons per year for smelting operation, which Chinese officials say will help shutter smaller operations.