Tantalum mainly exists in tantalite ore and is symbiotic with niobium. Tantalum has moderate hardness and ductility, and can be drawn into filaments to make thin foils. Its thermal expansion coefficient is very small.
1. Chemical properties of tantalum:
Tantalum also has excellent chemical properties and has extremely high corrosion resistance. It does not react to hydrochloric acid, concentrated nitric acid and "aqua regia" no matter under cold or hot conditions. However, tantalum can be corroded in hot concentrated sulfuric acid. Below 150°C, tantalum will not be corroded by concentrated sulfuric acid. It will only react at temperatures higher than this. In concentrated sulfuric acid at 175 degrees for one year, the thickness of the corrosion will be is 0.0004 mm. When tantalum is soaked in sulfuric acid at 200°C for one year, the surface layer is only damaged by 0.006 mm. At 250 degrees, the corrosion rate increased, with a thickness of 0.116 mm per year. At 300 degrees, the corrosion rate was even faster. After one year of immersion, the surface was corroded by 1.368 mm. The corrosion rate in fuming sulfuric acid (containing 15% SO3) is more serious than that in concentrated sulfuric acid. After being immersed in this solution at 130 degrees for one year, the thickness of the surface corroded is 15.6 mm. Tantalum will also be corroded by phosphoric acid at high temperatures, but this reaction generally occurs above 150 degrees. After soaking in 85% phosphoric acid at 250 degrees for one year, the surface will be corroded by 20 mm. In addition, tantalum will be corroded by hydrofluoric acid and nitric acid. It can be quickly dissolved in mixed acid and can also be dissolved in hydrofluoric acid. But tantalum is more afraid of strong alkali. In a caustic soda solution with a concentration of 110 degrees and a concentration of 40%, tantalum will be quickly dissolved. In a potassium hydroxide solution of the same concentration, it will be quickly dissolved at 100 degrees. Except for the above situation, general inorganic salts generally cannot corrode tantalum below 150 degrees. Experiments have shown that tantalum has no effect on alkali solutions, chlorine gas, bromine water, dilute sulfuric acid and many other chemicals at normal temperature. It only reacts under the action of hydrofluoric acid and hot concentrated sulfuric acid. Such situations are relatively rare in metals.
However, at high temperatures, the oxide film on the surface of tantalum is destroyed, so it can react with a variety of substances. Tantalum can react with fluorine at room temperature. At 150 degrees, tantalum is inert to chlorine, bromine and iodine. At 250 degrees, tantalum still has corrosion resistance to dry chlorine. When heated to 400 degrees in chlorine containing water vapor, it can still remain bright. At 500 degrees It begins to be corroded. Tantalum reacts with bromine above 300 degrees, and is inert to iodine vapor until the temperature reaches red heat. Hydrogen chloride reacts with tantalum at 410 degrees to produce pentachloride, while hydrogen bromide reacts with tantalum at 375 degrees. When heated to 200 degrees or lower, S can interact with Ta, and carbon and hydrocarbons can interact with tantalum at 800-1100 degrees.
2. Application of Tantalum:
Tantalum is extremely resistant to corrosion. This makes tantalum widely used in the chemical industry, such as in the manufacture of corrosion-resistant pressure vessels, reactors, pipelines and other equipment. Due to its stability and biocompatibility, tantalum is also used in the manufacture of medical devices such as artificial joints, dental implants and pacemakers. In addition, the application of tantalum in the electronics industry is also very important. Its good electrical conductivity and thermal stability make tantalum suitable for manufacturing high-end electronic components, such as capacitors, integrated circuits and semiconductor equipment.
In the aerospace industry, tantalum's high-temperature stability and corrosion resistance make it an ideal material for manufacturing aircraft and rocket components. Its applications include high-temperature components such as nozzles and turbine blades in aircraft engines. Tantalum also has refractory properties and low chemical activity, making it suitable as a minor component of alloys. It can even replace some precious metals, such as platinum, in the manufacture of experimental equipment.
Tantalum also has important applications in many high-tech fields such as the energy industry, communications and superconducting technology, such as anode materials used in the manufacture of lithium-ion batteries, high-frequency circuits and antennas. Overall, tantalum is a versatile material whose applications in various fields benefit from its unique chemical and physical properties.
