On the military side
Rare earth is called "gold" in industry. Because of its excellent physical properties such as photomagnetism, it can be combined with other materials to form new materials with different properties. Its most significant function is to greatly improve the quality and performance of other products. For example, the tactical performance of steel, aluminum alloy, magnesium alloy and titanium alloy used to manufacture tanks, planes and missiles will be greatly improved. Moreover, rare earth is also a lubricant for electronics, lasers, nuclear industry, superconductivity and many other high technologies. Once rare earth technology is used in the military, it will inevitably bring about a leap in military technology. In a sense, the overwhelming control of the US military in several local wars after the Cold War and its ability to openly kill the enemy without scruple stem from its advantages in the field of rare earth science and technology.
In the metallurgical industry
Adding rare earth metals, fluorides and silicides to steel can play the role of refining, desulfurization and neutralization of harmful impurities with low melting point, and can improve the machinability of steel; Rare-earth ferrosilicon alloy and rare-earth ferrosilicon magnesium alloy are used as nodulizers to produce rare-earth nodular cast iron, which are widely used in machinery manufacturing industries such as automobiles, tractors and diesel engines because they are particularly suitable for producing complex nodular cast iron with special requirements. Adding rare earth metals to non-ferrous alloys such as magnesium, aluminum, copper, zinc and nickel can improve the physical and chemical properties of the alloy and improve its mechanical properties at room temperature and high temperature.
In the petrochemical industry
Rare earth molecular sieve catalyst has the advantages of high activity, good selectivity and strong resistance to heavy metal poisoning, and it can replace aluminum silicate catalyst in the process of petroleum catalytic cracking. In the process of synthetic ammonia production, a small amount of rare earth nitrate is used as cocatalyst, and its gas treatment capacity is 1.5 times that of nickel-aluminum catalyst; In the process of synthesizing cis-polybutadiene rubber and isoprene rubber, rare earth naphthenate-triisobutyl aluminum catalyst is used, and the obtained products have the advantages of excellent performance, less equipment adhesion, stable operation and short post-treatment process. Composite rare earth oxides can also be used as catalysts for purifying the exhaust gas of internal combustion engines, and cerium naphthenate can also be used as paint drier.
In terms of glass ceramics
Rare earth oxide or processed rare earth concentrate can be widely used as polishing powder for polishing optical glass, spectacle lens, kinescope, oscilloscope tube, flat glass, plastic and metal tableware; In the process of melting glass, the strong oxidation of cerium dioxide to iron can be used to reduce the iron content in glass, so as to achieve the purpose of removing green from glass; Adding rare earth oxides can make optical glass and special glass with different uses, including glass that can pass infrared rays and absorb ultraviolet rays, glass that is acid-resistant and heat-resistant, and glass that can prevent X rays. Adding rare earth to ceramic glaze and porcelain glaze can reduce the fragmentation of glaze and make products show different colors, which is widely used in ceramic industry.
In terms of new materials
Rare earth cobalt NdFeB permanent magnet materials have high remanence, high coercivity and high magnetic energy product, which are widely used in electronics and aerospace industries. Garnet ferrite single crystals and polycrystals composed of pure rare earth oxides and iron oxides can be used in microwave and electronic industries. Neodymium glass made of yttrium aluminum garnet and high purity neodymium oxide can be used as solid laser materials; Rare earth hexaboride can be used to make cathode materials for electron emission; La-Ni metal is a newly developed hydrogen storage material in 1970s. Lanthanum chromate is a high temperature thermoelectric material; In recent years, superconducting materials made of barium-based oxides modified by barium, yttrium, copper and oxygen can obtain superconductors in liquid nitrogen temperature region, which makes a breakthrough in the research and development of superconducting materials. In addition, rare earths are also widely used in lighting sources, projection TV phosphors, intensifying screen phosphors, tricolor phosphors and copy lamp powders; In agriculture, applying a small amount of rare earth nitrate to field crops can increase the yield by 5 ~10%; In textile industry, rare earth chloride is also widely used in tanning fur, fur dyeing, wool dyeing and carpet dyeing.
The role of agriculture
The results show that rare earth elements can increase the chlorophyll content of plants, enhance photosynthesis, promote root development and increase the absorption of nutrients by roots. Rare earth can also promote seed germination, improve seed germination rate and promote seedling growth. In addition to the above main functions, it also has the ability to enhance the disease resistance, cold resistance and drought resistance of some crops. A large number of studies also show that the use of appropriate concentrations of rare earth elements can promote the absorption, transformation and utilization of nutrients by plants. Seed dressing of maize with rare earth advanced the emergence and jointing stage by 1 ~ 2 days, increased the plant height by 0.2 meters, advanced the seeds by 3 ~ 5 days, and increased the yield by 14%. When soybean seeds were dressed with rare earth, the emergence was advanced 1 day, the number of pods per plant increased 14.8 ~ 26.6, the number of three pods increased, and the yield increased 14.5% ~ 20.0%. Spraying rare earth can improve the Vc content, total sugar content and sugar-acid ratio of apple and citrus fruits, and promote fruit coloring and early maturity. It can also inhibit the respiratory intensity during storage and reduce the decay rate.
The argument that "China waged a rare earth war against the West" is flying all over the west. Rare earth, a resource distributed in many countries in the world, is described as China's "unique weapon" to blackmail other countries. The German Daily Mirror quoted the representative of German economic circles in Beijing as saying that China people play with rare earths just like the Organization of Petroleum Exporting Countries plays with oil. Newsweek said that rare earth is the "sword of Damocles" hanging over China's trading partners. 1, Japan. Japan, which has no rare earth resources but is a big consumer of rare earth in the world, exaggerates the argument of rare earth shortage the most. Although it bought rare earth cheaply from China and stored it for 20 years, it has made great progress in finding cheap rare earth suppliers around the world. Recently, Japanese diplomats frequently travel to India, Vietnam, Mongolia and Kazakhstan. These countries have one thing in common: they all have or may have rare earths. Japan quickly formed a "protest camp" with Europe and the United States, and Japanese media accused China of "weaponizing resources" just like the Russian way of playing with natural gas pipelines. And move out of the WTO rules to create international public opinion, the purpose is probably not only to force China to make substantial concessions to Japan on rare earth exports, but to isolate China from international public opinion. 2, the United States. American rare earth producers recently said that they plan to increase the annual output of rare earths in the United States to 20,000 tons by the end of 2065,438+02, and seize the 65,438+0/6 market at half the price of China. American rare earth producers point out that the quantity of rare earth transported and exported from China will definitely decrease. In order to break the situation that China controls the supply of rare earths, California Mine plans to start increasing production in June next year at 65438+ 10 1, and the project cost is 5 1 1 billion US dollars. On September 30th, the Assistant Secretary of the US Department of Energy said that it is imperative to diversify the supply sources of important resources. 3. European Union. According to Reuters, EU Trade Commissioner karel de gucht said on Wednesday that he will put pressure on China to ensure the supply of rare earths when he holds talks with China next month, although there is no conclusive evidence that China's restrictions on rare earth exports have harmed related industries in Europe. He said, "If necessary, we will definitely file a complaint with the World Trade Organization, but so far, there is no conclusive evidence that European companies are affected." 4. India-Japan cooperation. Indian Prime Minister Manmohan Singh told the media during his visit to Japan that India will take advantage of the "great opportunity" to promote cooperation with Japan in rare earth trade when China reduces its rare earth exports to Japan and Sino-Japanese relations are facing a test. Former Indian diplomats claimed that India-Japan cooperation could make China "dying". 5. The real purpose. "In fact, in addition to iron ore, the world's competition for oil and coal resources is still fierce, and the tragic degree is far greater than the competition for rare earths." Tang, an expert on Japanese issues at the Research Institute of China's Ministry of Commerce, said that it is a fact that some western countries exaggerate the "rare earth war". An expert in China said that rare earth should not be compared with other metal resources and oil, because they are different. The world only needs 1.2 million tons a year, which is a very small amount, and many of them are reserved by countries with strategic foresight. Rare earth is not a resource that is consumed like iron, copper, aluminum and oil at all, but a strategic element that can play a great role with only a little monosodium glutamate. The expert said that those countries that really need rare earths have already stored a lot of rare earths in China at a low price, so now China's control over rare earths will not threaten them at all. Their hype is actually to let China continue to supply them with rare earths at unreasonably low prices; At the same time, it consumes strategic resources with unique advantages in China. When China's advantage weakens, they will sell it back to China at an extremely expensive price. This is exactly the way for several big rare earth importers to compete with China. Some Japanese experts believe that countries with Japan as the prominent representative are making great efforts to find or restart the development of rare earths, and they do not rule out the gesture of containing China. Those countries that exchange resources for American political interests and strategic support will soon find themselves in a strategic passive position. The British Daily Telegraph article entitled "Rare Earth Dispute: Some Big Truth" said some fair words for China. The article quoted analysts as saying that rare earths have always been too cheap, and the world needs to get used to these materials becoming more and more expensive. In particular, China's local industries began to use more rare earths. "This is the result of China climbing up the value chain, which once again shows China's great influence on the world." Aiming at Jiangxi's unique rare earth resources, this project selects four rare earth oxides rich in rare earth minerals in southern Jiangxi as the research object to discuss their mineralization on cement clinker calcination, and uses typical rare earth tailings in southern Jiangxi as raw materials to prepare cement raw meal instead of clay ingredients, and studies their effects on cement clinker mineral formation and clinker properties. By means of chemical analysis, differential thermal analysis, ICP-AES analysis, X-ray diffraction, crystal microscope and scanning electron microscope, the characteristics of raw meal and the effects of rare earth oxides and rare earth tailings on carbonate decomposition, burnability of raw meal, morphology and composition of clinker minerals and mechanical properties of cement were systematically studied. The results show that rare earth oxides have little effect on carbonate decomposition, but can improve the burnability of raw meal. Rare earth oxides can promote the formation of an ore and the development of minerals in clinker, which is beneficial to the uniform grain size and distribution of minerals in clinker. However, excessive addition of some rare earth oxides may cause melting erosion of minerals and affect their hydration activity. Under the condition of good calcination, rare earth oxides and tailings can improve the strength of clinker, but have little effect on the setting time of cement. Due to the high sand content of the samples mixed with tailings, the burnability of raw meal is lower than that of raw meal mixed with clay. Improving the grinding fineness of raw meal can further improve the burnability of raw meal. Portland cement clinker with excellent performance can be fired by using rare earth tailings instead of clay ingredients. Combined with the petrographic analysis of clinker, the distribution of rare earth oxides in clinker was analyzed by SEM-EDS. ...