China has suspended exports of a wide range of critical minerals and magnets, threatening to choke off supplies of components central to automakers, aerospace manufacturers, semiconductor companies and military contractors around the world.

中国暂停了多种关键矿产和磁铁的出口，此举可能切断对全球汽车制造商、航空航天制造商、半导体企业和军事承包商来说至关重要的零部件供应。

Shipments of the magnets, essential for assembling everything from cars and drones to robots and missiles, have been halted at many Chinese ports while the Chinese government drafts a new regulatory system. Once in place, the new system could permanently prevent supplies from reaching certain companies, including American military contractors.

磁铁对于汽车、无人机到机器人和导弹等各种产品的组装过程都必不可少。在中国政府起草新的监管体系之际，中国许多港口已停止了磁铁的运输。一旦到位，新系统可能永久性阻止某些公司获得供应，包括美国的军工承包商在内。

The official crackdown is part of China’s retaliation for President Trump’s sharp increase in tariffs that started on April 2.

官方的这一举措是中国对特朗普总统自4月2日起大幅提高关税的报复行动的一部分。

On April 4, the Chinese government ordered restrictions on the export of six heavy rare earth metals, which are refined entirely in China, as well as rare earth magnets, 90 percent of which are produced in China. The metals, and special magnets made with them, can now be shipped out of China only with special export licenses.

4月4日，中国政府下令限制六种仅在中国提炼的重稀土金属，以及稀土磁铁（其中90%产自中国）的出口。这些金属以及用它们制造的特殊磁铁现在只有在获得特殊出口许可证的情况下才能运出中国。

But China has barely started setting up a system for issuing the licenses. That has caused consternation among industry executives that the process could drag on and that current supplies of minerals and products outside of China could run low.

然而，中国才刚刚开始着手建立许可证发放制度。这引起了业内高管的惊恐，他们担心这一过程可能会持续拖延，而且还担心中国境外的现有矿产和产品供应可能出现短缺。

If factories in Detroit and elsewhere run out of powerful rare earth magnets, that could prevent them from assembling cars and other products with electric motors that require these magnets. Companies vary widely in the size of their emergency stockpiles for such contingencies, so the timing of production disruptions is hard to predict.

如果底特律和其他地方的工厂用完现有的强力稀土磁铁，它们可能就无法装配汽车和其他需要这些磁铁的电机产品。针对这类突发事件，各公司的应急储备规模差别很大，因此很难预测生产中断的时间。

中国常熟的一家工厂正在加工含有重稀土金属的化学品，以用于发光二极管。这些金属还用于制造喷气发动机、激光器、汽车前大灯和某些火花塞的化学品。

The so-called heavy rare earth metals covered by the export suspension are used in magnets essential for many kinds of electric motors. These motors are crucial components of electric cars, drones, robots, missiles and spacecraft. Gasoline-powered cars also use electric motors with rare earth magnets for critical tasks like steering.

暂停出口所涉及的所谓重稀土金属用于制造多种电动机所必需的磁铁。这些发动机是电动汽车、无人机、机器人、导弹和航天器的关键部件。燃油车也使用带有稀土磁铁的电动机来完成转向等关键任务。

The metals also go into the chemicals for manufacturing jet engines, lasers, car headlights and certain spark plugs. And these rare metals are vital ingredients in capacitors, which are electrical components of the computer chips that power artificial intelligence servers and smartphones.

这些金属还可以用于制造喷气发动机、激光、汽车前灯和某些火花塞的化学品。这些稀有金属也是电容器的重要成分，而电容器是为人工智能服务器和智能手机提供动力的计算机芯片的电子元件。

Michael Silver, the chairman and chief executive of American Elements, a chemicals supplier based in Los Angeles, said his company had been told it would take 45 days before export licenses could be issued and exports of rare earth metals and magnets would resume. Mr. Silver said that his company had increased its inventory last winter in anticipation of a trade war between the United States and China, and could meet its existing contracts while waiting for the licenses.

总部位于洛杉矶的化学品供应商美国元素公司董事长兼首席执行官迈克尔·西尔弗表示，他的公司已被告知，需要45天才能发放出口许可证，届时稀土金属和磁铁的出口才能恢复。西尔弗说，他的公司去年冬天增加了库存，因为预见到了中美之间会爆发贸易战，在等待许可证的同时，它可以履行现有的合同。

Daniel Pickard, the chairman of the critical minerals advisory committee for the Office of the United States Trade Representative and Department of Commerce, expressed concern about the availability of rare earths.

美国贸易代表办公室和商务部关键矿产咨询委员会主席丹尼尔·皮卡德对稀土的供应情况表示担忧。

“Does the export control or ban potentially have severe effects in the U.S.? Yes,” he said. Mr. Pickard, leader of the international trade and national security practice at the Buchanan Ingersoll & Rooney law firm, said a swift resolution of the rare earths issue was necessary because a sustained disruption of exports could hurt China’s reputation as a reliable supplier.

“出口管制或禁令是否可能对美国产生严重影响？答案是肯定的，”他说。皮卡德是布坎南英格索兰和鲁尼律师事务所国际贸易和国家安全业务的负责人，他说，迅速解决稀土问题是必要的，因为持续的出口中断可能会损害中国作为可靠供应国的声誉。

中国最有名的稀土磁铁工厂由总部位于赣州的金力永磁公司运营。

In a potential complication, China’s Ministry of Commerce, which issued the new export restrictions jointly with the General Administration of Customs, has barred Chinese companies from having any dealings with an ever-lengthening list of American companies, particularly military contractors.

中国商务部与海关总署联合发布了新的出口限制，禁止中国公司与越来越多的美国公司，特别是军工承包商进行任何交易，这可能会使情况变得更加复杂。

One American mining leader, James Litinsky, the executive chairman and chief executive of MP Materials, said that rare earth supplies for military contractors were of particular concern.

美国矿业领袖、MP材料公司的执行主席兼首席执行官詹姆斯·利廷斯基表示，军事承包商的稀土供应情况尤其令人担忧。

“Drones and robotics are widely considered the future of warfare, and based on everything we are seeing, the critical inputs for our future supply chain are shut down,” he said. MP Materials owns the sole rare earths mine in the United States, the Mountain Pass mine in the California desert near the Nevada border, and hopes to start commercial production of magnets in Texas at the end of the year for General Motors and other manufacturers.

他说：“无人机和机器人被广泛视为未来战争的发展方向，根据我们所看到的所有情况，我们未来供应链的关键投入已经关闭。”MP材料公司拥有美国唯一的稀土矿——位于内华达州边境附近加州沙漠中的帕斯山矿，该公司希望今年年底在得克萨斯州开始为通用汽车和其他制造商商业化生产磁铁。

A few Japanese companies keep rare earth inventories of more than a year’s supply, having been hurt in 2010, when China imposed a seven-week embargo on rare earth exports to Japan during a territorial dispute.

一些日本公司拥有超过一年使用量的稀土库存，2010年，中国因领土争端对日本实施了为期七周的稀土出口禁运，这些企业深受影响。

But many American companies keep little or no inventory because they do not want to tie up cash in stockpiles of costly materials. One of the metals subject to the new controls, dysprosium oxide, trades for $204 per kilogram in Shanghai, and much more outside China.

但是，许多美国公司只有很少库存或根本没有库存，因为它们不想把现金浪费在昂贵材料的库存上。此次受到新的管制措施影响的金属之一——氧化镝，在上海的交易价格为每公斤204美元，在中国境外的交易价格要高得多。

Rare earth magnets make up a tiny share of China’s overall exports to the United States and elsewhere. So halting shipments causes minimal economic pain in China while holding the potential for big effects in the United States and elsewhere.

稀土磁铁在中国对美国和其他国家的整体出口中只占很小的份额。因此，暂停出口对中国的经济影响微乎其微，而对美国和其他地方却有可能产生重大影响。

Chinese customs officials are blocking exports of heavy rare earth metals and magnets not just to the United States but to any country, including Japan and Germany. Enforcement of the new export license requirement, though, has been uneven so far among different Chinese ports, rare earth industry executives said.

中国海关官员不仅禁止向美国出口重稀土金属和磁铁，还禁止向包括日本和德国在内的任何国家出口。不过，稀土行业高管称，到目前为止，中国不同港口对新出口许可证要求的执行情况并不一致。

Most but not all rare earth magnets include heavy rare earths, which are needed to prevent magnets from losing their magnetism at high temperatures or in some electrical fields. Some rare earth magnets are made only from light rare earths, and are not subject to export restrictions. Customs officials at a few Chinese ports are tolerating exports of magnets if they have only tiny traces of heavy rare earth metals in them, and if the magnets are not going to the United States.

大多数、但并非所有稀土磁铁都包括重稀土，重稀土是防止磁铁在高温或某些电场中失去磁性所必需的。一些稀土磁铁仅由轻稀土制成，不受出口限制。一些中国港口的海关官员允许磁铁出口，前提是磁铁中只含有微量的重稀土，而且这些磁铁不运往美国。

Officials at other Chinese ports are taking a more stringent stance, however, demanding that exporters run tests to prove that any batch of magnets does not have heavy rare earth metals in them before the magnets can be loaded on a ship for export.

然而，中国另外一些港口的官员采取更为严格的立场，要求出口商在装船出口之前进行检测，证明任何一批磁铁都不含重稀土。