Rare earth is a general term for lanthanides and scandium, yttrium and other 17 metal elements in the periodic table. There are 250 kinds of rare earth minerals in nature. Finnish chemist Gadolin was the first person to discover rare earths. 1794, he separated the first rare earth "element" (yttrium soil, that is, Y2O3) from a heavy ore shaped like asphalt. Because few rare earth minerals were found in the18th century, only a small amount of water-insoluble oxides could be obtained by chemical methods. Historically, this oxide was customarily called "soil", hence the name rare earth. According to the electronic shell structure and physical and chemical properties of rare earth elements, as well as their occurrence in minerals and the characteristics that different ionic radii can produce different properties, seventeen rare earth elements are usually divided into two groups: light rare earth elements include lanthanum, cerium, praseodymium, neodymium, promethium, samarium and europium. Heavy rare earths include gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium and yttrium. Classification by extraction and separation: light rare earth (P204 weak acid extraction)-lanthanum, cerium, praseodymium, neodymium; Medium rare earth (P204 low acidity extraction)-samarium, europium, gadolinium, terbium, dysprosium; Heavy rare earth elements (acidic extraction in P204)-holmium, erbium, thulium, ytterbium, lutetium and yttrium.
At its peak, China's rare earth reserves accounted for 7 1. 1% of the world's, and now it accounts for less than 23%. The rare earth reserves in China decreased by 37% from 1996 to 2009, leaving only 27 million tons. According to the current production speed, China's medium and heavy rare earth reserves can only be maintained for 15 to 20 years, and it must be imported from abroad around 2040-2050 to meet domestic demand. China is not the only country with rare earths in the world, but it has taken on the role of supplying rare earths to the world in the past decades, resulting in the destruction of its natural environment and the consumption of its own resources. Japan began to search for rare earth resources that can replace China in the world. Tokyo plans to invest $654.38+0.2 billion to improve the supply of rare earths. Japan has reached an agreement with Mongolia Lightning to develop the country's rare earth resources from this month. South Korea, another big consumer of rare earths, has a similar plan. At the beginning of this month, South Korea announced an investment of US$ 6.5438+0.5 million, and reserved 654.38+0.200 tons of rare earth before 2065.438+06.