Bismuth is a silvery white to pink metal that is brittle and easy to crush. Its chemical properties are relatively stable. Bismuth exists in nature in the form of free metal and minerals .
1. [Nature]
Pure bismuth is a soft metal, while impure bismuth is brittle. It is stable at room temperature. Its main ores are bismuthinite (Bi2S5) and bismuth ochre (Bi2o5). Liquid bismuth expands when solidified.
It is brittle and has poor electrical and thermal conductivity. Bismuth selenide and telluride have semiconductor properties.
Bismuth metal is a silvery white (pink) to light yellow luster metal , brittle and easy to crush; at room temperature, bismuth does not react with oxygen or water and is stable in the air. It has poor electrical and thermal conductivity; bismuth was previously considered to be the most stable element with the largest relative atomic mass, but in 2003, it was discovered that bismuth is weakly radioactive and can decay into thallium-205 through α decay . Its half-life is about 1.9X10^19 years, which is 1 billion times the life of the universe.
2. Application
semiconductor
Semiconductor components made by combining high-purity bismuth with tellurium, selenium, antimony, etc. and pulling crystals are used for thermocouples , low-temperature thermoelectric power generation and thermorefrigeration. They are used to assemble air conditioners and refrigerators. Artificial bismuth sulfide can be used to manufacture photoresistors in photoelectric devices to increase the sensitivity in the visible spectrum region.
Nuclear Industry
High-purity bismuth is used as a heat carrier or coolant in nuclear industry reactors and as a material for protecting atomic fission devices.
Electronic Ceramics
Bismuth-containing electronic ceramics such as bismuth germanate crystals are a new type of scintillating crystals used in the manufacture of nuclear radiation detectors , X-ray tomography scanners , electro-optics, piezoelectric lasers and other devices; bismuth calcium vanadium (pomegranate ferrite is an important microwave gyromagnetic material and magnetic cladding material), bismuth oxide-doped zinc oxide varistors , bismuth-containing boundary layer high-frequency ceramic capacitors , tin-bismuth permanent magnets , bismuth titanate ceramics and powders, bismuth silicate crystals , bismuth-containing fusible glass and more than 10 other materials have also begun to be used in industry.
Medical treatment
Bismuth compounds have the effects of astringency, antidiarrhea, and treatment of gastrointestinal dyspepsia . Bismuth subcarbonate, bismuth subnitrate , and potassium bismuth subrubberate are used to make stomach medicines. The astringent effect of bismuth drugs is used in surgery to treat trauma and stop bleeding. In radiotherapy , bismuth-based alloys are used instead of aluminum to make protective plates for patients to prevent other parts of the body from being exposed to radiation. With the development of bismuth drugs, it has been found that some bismuth drugs have anti-cancer effects.
Metallurgical Additives
Adding trace amounts of bismuth to steel can improve the processing properties of the steel, and adding trace amounts of bismuth to malleable cast iron can make it have properties similar to those of stainless steel.
Post time: Mar-14-2024