China’s medium and heavy rare earths reserves may only last 15-20 years at the current rate of production needs, Chao Ning, section chief of foreign trade at the Ministry of Commerce, said today at a conference.

“We can not rule out the possibility that China may need to rely on imports sometime in the future for these minerals, instead of supplying the world,” Chao said.

China’s rare earths deposits dropped to 27 million tons by the end of 2009, or just 30 percent of the world’s total known reserves, from 43 million tons, or 43 percent of the world total, in 1996, Chao said.

To contact the editor responsible for this story: Bloomberg News at [email protected]