One article takes you into rare earths (part two)

As a large country of rare earth resources, China is changing from the development of rare earth raw materials to the promotion and application of rare earths, instead of relying on the export of rare earth minerals to make profits. Rare earth, known as industrial vitamin, has great effect and low dosage, so it is widely used in various industries.

In 2020, rare earth permanent magnets account for the largest proportion of rare earth downstream consumption in China, followed by metallurgical machinery, petrochemical industry, polishing materials, glass ceramics, hydrogen storage, catalysis, luminescence, agriculture and other fields. This paper mainly introduces the applications of rare earths in permanent magnet, hydrogen storage, luminescence, catalysis and polishing.

Rare earth permanent magnet material

The rare earth permanent magnet material is an alloy composed of samarium and neodymium mixed rare earth metals and transition metals (such as cobalt, iron, etc.). It is a kind of magnetic material prepared by powder metallurgy pressing sintering and magnetization. The specific classification is shown in the following figure:

Whether in the global market or the domestic market, rare earth permanent magnet materials show low-end oversupply and high-end undersupply. According to SMM research, China's sintered NdFeB blank output in 2020 was about 190000 tons, an increase of 11.8 percent from 170000 tons in 2019. Among them, the output of high-performance sintered NdFeB blank is 51300 tons, accounting for only 27% of the total NdFeB blank.

China's rare earth permanent magnet industry is widely distributed in China, including Inner Mongolia, Shanxi, Shandong, Shaanxi, Jiangxi, Zhejiang and other places. In recent years, the concentration of rare earth permanent magnet industry in China is increasing, and the development trend of industrial cluster in Ningbo, Zhejiang Province is obvious.

At present, there are more than 200 sintered NdFeB enterprises in China, with a total annual production capacity of 24-250000 tons per year. Among them, there are no more than 20 NdFeB enterprises with an annual production capacity of more than 3000 tons. China's representative enterprises producing high-performance NdFeB include Jinli permanent Magnet, Zhongke Sanhuan, Ningbo Yunsheng, Yingluohua, Yantai Zhenghai and so on. Some enterprises are still carrying out production expansion and reconstruction. As the largest downstream area of the rare earth industry and the fastest growing area in the future, with the development of downstream application fields, the market demand of rare earth permanent magnet materials will continue to release.

Rare earth hydrogen storage materials

Rare earth hydrogen storage materials can be divided into AB5 type and non-AB5 type rare earth hydrogen storage alloys, which can absorb and release hydrogen at appropriate temperature and pressure. Lanthanum, cerium and other rare earth elements are mainly used as negative electrode materials for Ni-MH batteries.

Rare earth hydrogen storage materials are mainly used in the field of hybrid electric vehicles, and the main domestic production enterprises include Xiamen tungsten industry, Baotou Sande battery, Sihui City Dabowen and so on.

Rare earth hydrogen storage materials are closely related to the development of Ni-MH batteries. At present, Ni-MH batteries are the mainstream of commercial use, and Ni-MH batteries are widely used in hybrid electric vehicles, including Toyota Prius, which has the highest sales in the world. From the perspective of the industry cycle, Ni-MH battery has entered the mature stage, formed a large-scale production, and has the advantage of price.

More than 70% of the world's Ni-MH batteries are made in China, followed by Japan, which accounts for more than 95% of the world's total output. SMM expects China's production of rare earth hydrogen storage materials to be 12000 tonnes in 2021, up 8 per cent from a year earlier.

Rare earth luminescent materials

The luminescent materials of rare earth in China are mainly LED phosphor, long afterglow phosphor and tricolor phosphor.

Nowadays, most of the new electric light sources widely used in the world are related to rare earths, among which the most widely used electric light sources are rare earth tricolor fluorescent lamps. Tricolor refers to the three basic colors of red, green and blue. after the combination of mixed colors, the white light for lighting can be obtained. The red, green and blue phosphors used in rare earth tricolor fluorescent lamps are mainly composed of rare earth elements such as yttrium, europium and terbium.

Rare earth tricolor phosphors are the main raw materials used in the production of high-efficiency energy-saving lamps all over the world. Compared with the ordinary incandescent lamp, the rare earth tricolor energy-saving lamp has a power saving rate of up to 80%, and can obtain a color temperature similar to that of sunlight, so that the color of the illuminated object is pure and undistorted, and its production process does not pollute the environment.

Rainbow display device Co., Ltd., Jiangmen Keheng Industrial Co., Ltd., Youyan New Materials Co., Ltd., Hangzhou Daming fluorescent Materials Co., Ltd., Jiangsu Bolui Radio and Television Co., Ltd. are mainstream manufacturers of rare earth light-emitting materials.

Rare earth catalytic materials

Rare earth catalytic materials are mainly divided into motor vehicle exhaust purification catalysts and petroleum cracking catalysts. The rare earth materials used are mainly the mixture of cerium oxide, praseodymium oxide and lanthanum oxide, in which cerium oxide is the key component.

Motor vehicle exhaust purification catalyst is mainly used to purify automobile exhaust, among which rare earth-based three-way catalyst is the most widely used, which is favored because of its low price, good thermal stability, high activity and long service life.

Molecular sieve rare earth catalytic materials are used in petroleum cracking catalysts, which can greatly increase the cracking conversion of crude oil and increase the yield of gasoline and diesel oil. The application of rare earth molecular sieve catalyst in petroleum cracking catalysis has the advantages of large crude oil treatment capacity, high light oil yield, high product quality, high activity, low coke formation rate, low catalyst loss, good selectivity and so on.

The main production enterprises of rare earth catalysts in China include Sinopec Catalyst Co., Ltd., Sichuan Runhe Catalytic New Materials Co., Ltd., Hongda Industrial Co., Ltd., etc.

Rare earth polishing powder

Rare earth polishing powder is a kind of mixed light rare earth oxide powder with cerium oxide as the main component, which can be used to improve the surface finish of parts. It is widely used in polishing optical glass, glasses, picture tube, oscilloscope tube, flat glass, plastic and metal tableware. Since the 1960s, China has had the ability to produce various specifications of polishing powder using mixed rare earth carbonate, fluorocarbon cerite and cerium oxide as raw materials.

According to the content of cerium oxide, the polishing powder can be divided into three kinds of rare earth polishing powder: high, medium and low cerium.

According to the size and particle size of polishing powder, it can be divided into nanometer rare earth polishing powder, submicron rare earth polishing powder and micron rare earth polishing powder.

According to the statistics of polishing Materials Branch of China rare Earth Industry Association, the output of polishing powder from five major enterprises in the industry accounts for more than 70% of the total output of the whole year. China's main production enterprises of rare earth polishing powder are Tianjiao Qingmei, Zibo Ganoderma lucidum, Zibo Xinfangyuan Chemical Industry, Gansu rare Earth, Baotou Zhongke Yuhang and so on. Benefiting from the development of the electronics industry and the national regulation and control of the rare earth industry policy, the number of rare earth polishing powder enterprises has increased rapidly in recent years, and the production capacity has expanded rapidly. The output of rare earth polishing powder in China is expected to reach 37000 tons in 2021.