Among the rare earth metals are cerium, praseodymium, neodymium, yttrium, lanthanum, and dysprosium. The earth's crust contains a group of elements called these metals. They are widely used in a variety of applications, including catalysts, glass, ceramics, phosphors, metal alloys, permanent magnets, pigment, metallurgy, and glass and ceramics.
With the exception of scandium, rare-earth elements are heavier than iron and are thus created by asymptotic giant branch stars or supernova nucleosynthesis. Trace amounts of radioactive promethium are created naturally when uranium-238 spontaneously fissions, but the majority of promethium is created artificially in nuclear reactors. Because rare earths are chemically similar, geochemical processes only slightly alter their concentrations in rocks, making their proportions useful for geochronology and dating fossils. Global Rare Earth Metals Market was valued at US$ 4710.8 Million in 2021 in terms of revenue, exhibiting a CAGR of 6.24 % during the forecast period (2022 to 2030). India has access to some REEs, including lanthanum, cerium, neodymium, praseodymium, and samarium, among others. Others, including the HREEs dysprosium, terbium, and europium, are not present in extractable amounts in Indian deposits. As a result, there is a reliance on nations like China for HREEs. China is one of the top producers of REEs, accounting for an estimated 70% of global production. Since Beijing was constantly altering the quantities that it would permit to be produced and exported, supplies from China had already started to become erratic as early as 1990. The USGS also claims that the Chinese government started to restrict the number of businesses, including Sino-foreign joint ventures, that were allowed to export REEs from China. These metals react slowly with cold water to form hydroxides, which release hydrogen, and tarnish gradually in air at room temperature. They create oxides when they interact with steam, which ignite spontaneously at a temperature of 400°C. Apart from a few specialised enzymes, like lanthanide-dependent methanol dehydrogenases in bacteria, these elements and their compounds serve no biological purpose. The insoluble compounds are not toxic, whereas the water-soluble ones are mildly to moderately toxic. Contrary to what they are called, rare-earth elements are actually quite common in the crust of the Earth, with cerium being the 25th most common element with 68 parts per million, more common than copper. Except for a tiny amount produced by spontaneous fission of uranium-238, all promethium isotopes are radioactive and do not naturally exist in the earth's crust. They are frequently discovered in thorium- and less frequently uranium-containing minerals. Rare-earth elements are typically dispersed and not frequently found concentrated in rare-earth minerals because of their geochemical characteristics. As a result, there are few economically viable ore deposits (i.e. "rare"). Gadolinite, a black mineral made up of cerium, yttrium, iron, silicon, and other elements, was the first rare-earth mineral found (1787). The earth's crust contains a lot of rare earth elements, with cerium being the 25th most common element with 68 parts per million. It is therefore as common as copper. Rare earth elements are typically dispersed due to their geochemical properties. This indicates that they are not frequently found in sufficiently concentrated clusters to be mineable. These minerals were given the name "rare earths" due to their rarity. The Lanthanide series, which consists of 15 elements plus yttrium, is a subgroup of the periodic table known as rare earths. Light elements (from lanthanum to samarium) and heavy elements are used to categorise rare earths (europium to lutetium). The latter are more expensive because they are less common.
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