摘要:Rare earths were not mined domestically in 2016. Bastnaesite, a rare-earth fluorocarbonate mineral, was previously mined as a primary product at Mountain Pass, CA, which was put on care and maintenance in the fourth quarter of 2015. The estimated value of rare-earth compounds and metals imported by the United States in 2016 was $120 million, a decrease from $160 million imported in 2015. The estimated distribution of rare earths by end use was as follows: catalysts, 55%; metallurgical applications and alloys, 15%; ceramics and glass, 10%; polishing, 10%; and other, 10%.