There are two kinds of rare earths: light rare earths and medium heavy rare earths. Light rare earths are mostly used in making screens, sunscreens, glass products and other civilian fields, while medium and heavy rare earths are widely used in military and aviation fields because of their abundant reserves.
Rare earth plays an irreplaceable role in fluorescence, magnetism, optical fiber communication, metallurgy, hydrogen storage, laser and other fields. China is rich in rare earth reserves and monopolizes the world. It is the only country that can provide 17 kinds of rare earths, and the proven reserves of rare earths in China account for nearly 40% of the world.
China has the world-leading rare earth mining and smelting separation technology, thus becoming the only country in the world with a complete rare earth industrial chain. Meng Qingjiang, executive deputy secretary general of Jiangxi Rare Earth Society, said: Rare earths mined abroad can only be sent to China. ?
Therefore, most of the rare earths in other countries are transported to China for smelting and separation, and a considerable part of the rare earths in China are imported from foreign countries, refined and finally exported.
China imported about 25,000 tons of rare earths and oxides from the United States in 2065,438+08, making it the largest importer of rare earths. This not only ensures that China's rare earth reserves will not be excessively consumed, but also prevents rare earth enterprises in Europe and America from making a comeback.
Many people say that one of China's three trump cards to the United States is to control the export of rare earths to the United States.
Among the materials and equipment made of rare earth, China, a rare earth permanent magnet, occupies a monopoly position. As the name implies, rare earth permanent magnets contain rare earth metals as alloying elements.
Rare earth permanent magnet materials are important materials in electronic technology communication, which are mainly used in traveling wave tubes and circulators in satellites and radars, as well as electronic instruments such as micro-motors, micro-recorders, aviation instruments, electronic watches and seismographs.
In addition, the application of rare earth permanent magnets has penetrated into the fields of automobiles, household appliances, electronic instruments, nuclear magnetic resonance imaging machines, audio equipment, micromotors, mobile phones and so on.
Last year, Chinese mainland's magnet exports totaled 1 178 million US dollars, of which 257 million US dollars came from Chinese mainland.
It is worth mentioning that the rare earth magnet processing plants outside China are mainly in Japan and Germany, but the rare earths in these two countries are also imported from China. Even if other countries have rare earth mines, their rare earth processing is still inseparable from China.
Citigroup reported that if China only restricts the export of rare earth metals and rare earth alloys to the United States, and the processing capacity outside China is rapidly established, the United States can still cope. However, if the restrictions are extended to finished products such as magnets and permanent magnet motors, the situation will be much more serious, and some special industries in the United States may fall into the dilemma of supply interruption.
In order to obtain China's rare earth permanent magnet materials, the United States even exchanged rhenium. Rhenium is a rare refractory metal, its content in the earth's crust is only one billion, its melting point is 3 180℃, and its boiling point is 5627℃. Pure rhenium is soft and looks like platinum. It not only has good plasticity, mechanical properties and creep resistance, but also has good wear resistance and corrosion resistance.
Rhenium and its alloys are widely used in aerospace, electronic industry, petrochemical industry and other fields. Rhenium plays an important role in jet engines, especially rocket engines. Rhenium can double the engine life and improve the high temperature resistance of engine turbofan blades. The melting point of rhenium is as high as 3 100 degree, and its strength is extremely high. When it is applied to hollow single crystal turbine blades, it can make the engine afterburner, work longer, and is not easy to be damaged, which plays a great role in improving the thrust of the engine.
Therefore, about 80% of rhenium in the world is used to produce aero-engines, which is of great significance in military strategy and is one of the necessary choices for strategic reserves of various countries.
But it is harder to get than diamonds. According to the report of the US Geological Survey, the proven rhenium reserves in the world are only about 2,500 tons, among which the rhenium reserves in the United States rank first in the world. The United States and some other western countries have imposed a material and technical blockade on China all the year round in order to maintain their dominant position in the aviation industry. Rolls royce, a British aero-engine giant, invested in China, but strengthened its staff in China.
In 20 10, the workers accidentally discovered the rare metal rhenium in the mine at the southern foot of Huashan Mountain, with a reserve of 176 tons, accounting for about 7% of the global reserves. Chengdu Aerospace has purified rhenium and produced qualified single crystal blades, but the domestic rhenium production is far from enough.
At this time, China took advantage of its rare-earth advantages to let the United States exchange rhenium for rare-earth permanent magnet materials through an embargo. At present, the J-20 engine in China is said to be made of rhenium.
But let's not be too happy. China still lags behind the United States in many core technologies and materials. China needs to continue its efforts.