Rubidium is a silvery-white light metal. In the 1850s, German chemist Bunsen accidentally discovered this metal. Rubidium's chemical reactivity is even greater than that of potassium; it reacts very easily with oxygen to form oxides, can spontaneously ignite in air, and reacts with water releasing a large amount of heat, causing the hydrogen to ignite immediately. Therefore, pure rubidium must be kept away from air during production, storage, and transportation. Usually, rubidium is stored in inert gas, liquid paraffin, or in a vacuum. Because rubidium is difficult to preserve, its use in industrial applications is limited.
Things are valuable because they are rare. The global reserves of pure rubidium are 180,000 tons, with an annual world production of 4 tons. Most rubidium exists in nature in the form of oxides. Rubidium does not have standalone industrial minerals and is often dispersed in mica, pollucite, salt layers, and other sources. Substances with a rubidium content of 99.5% are priced at 256,000 yuan per kilogram, while those with 99.9% content can reach as high as 299,000 yuan per kilogram. This shows that rubidium is truly expensive.
Rubidium is so expensive not only because it is rare, but also because of its uses. With the advancement of science and technology, rubidium is used in many fields. It is mainly used in special glass; when producing special glass, adding rubidium carbonate as an additive can reduce the glass's conductivity, extend its lifespan, and increase its stability. Nowadays, rubidium-containing special glass is widely used in night vision devices, fiber optic communications, and other fields. Rubidium salts, such as rubidium chloride, can be used as density gradient media in the ultracentrifugation of DNA and RNA, and radioactive rubidium can be used as a tracer in blood flow studies. Rubidium iodide can sometimes replace potassium iodide to treat goiter, which is an enlargement of the thyroid gland. In addition, rubidium salts can also be used as sedatives and to treat epilepsy.
In addition, rubidium can also be used in the aerospace field. The development of space technologies such as the launch systems of artificial Earth satellites, navigation, rocket navigation, missile systems, wireless communication, and GPS increasingly demands high short-term and long-term accuracy and stability of frequency and time standards. Rubidium's radiation frequency remains relatively stable over long periods, perfectly meeting these requirements. Rubidium atomic clocks, which are extremely accurate, will not deviate by more than one second over 3.7 million years.
Although rubidium ore is rare, it is not nonexistent. Previously, geological survey departments in Guangdong discovered rare, giant rubidium ore deposits in Zijin County and Jiaoling County, located in the southern section of the Wuyi metallogenic belt in Guangdong. The estimated rubidium resources in these two areas exceed 3.6 million tons, and experts say their potential economic value could be calculated in trillions. Meanwhile, the total confirmed rubidium resources across 19 mineral sites in China amount to 1.85 million tons, but most of them are difficult to utilize. The estimated resources at the two rubidium sites in Guangdong are respectively 1,000 and 800 times the national standard for large ore deposits, with relatively high recovery rates. The discovery of these two rubidium deposits in Guangdong represents a breakthrough in mineral exploration in China. Moreover, China is also the first country in the world to independently possess rubidium mineral resources.
The discovery of rubidium ore is of great significance to our country. Rubidium can also be used in high-tech fields such as energy and the national defense industry. Especially in the energy sector, as the world's energy resources become increasingly scarce, people are eager to find a new energy source that can reduce environmental pollution, save fuel, and be highly efficient. Rubidium and its compounds have shown promising prospects in new energy conversion, and the whole world is paying attention to this new energy.