In the periodic table, a large number of metals are labeled as "rare metals". As the saying goes, "rarity breeds value". Is it because their reserves in nature are scarce? In fact, when it comes to reserves, some rare metals are actually quite abundant! For example, titanium is a rare metal, but its content in the Earth's crust is even greater than that of common metals such as lead, zinc, copper, and tin. In the kingdom of metals, its reserves rank seventh, just behind aluminum, iron, calcium, sodium, potassium, and magnesium. So why is titanium called a rare metal?
It turns out that the origin of the term "rare metal" is not only because some metals have lower reserves or are more scattered in the Earth's crust, but also because they were discovered and applied in industrial technology much later than other metals. At the beginning of their discovery, many rare metals had the characteristics of scattered distribution, low content, difficult extraction, and limited application. For example, people discovered titanium dioxide in titanomagnetite as early as 1789, but due to the high melting point of titanium (1660°C), it must be smelted at high temperatures, and titanium's chemical properties are very active at high temperatures. Therefore, it was not until around the 1950s that people developed titanium smelting processes and equipment. Thirty years later, titanium production saw significant growth.
In the past, due to relatively backward separation and extraction technologies, most research on rare metals was limited to superficial understanding. After the 19th century, related physical and chemical technologies developed rapidly. Especially since the Second World War, research and applications of rare metals have developed rapidly. In addition to their applications in the traditional three materials fields of steel, glass, and ceramics, their consumption share in new materials has also increased significantly over the years, reaching 55.6% in 2005. Rare metals have evolved from an optional "industrial seasoning" to an indispensable "industrial vitamin". Almost every 3-5 years, people discover a new use for rare metals. For example, metal titanium has risen to become the "third metal" after iron and aluminum.
Today, rare metals are mainly used in rare earth permanent magnets, polishing materials, hydrogen storage alloys, and automotive exhaust purifiers, and maintain a rapid growth momentum. Scientists predict that rare metals will play an even more extensive and important role in future industries, military, medicine, scientific research, and daily life.