Bismuth and its uses
Bismuth, which has been known since ancient times, was often confused with lead and tin. Bismuth was first shown to be a distinct element in 1753 by Claude Geoffroy the Younger. Bismuth does occur free in nature and in such minerals as bismuthinite (Bi2S3) and bismite (Bi2O3). The largest deposits of bismuth are found in Bolivia, although bismuth is usually obtained as a by-product of mining and refining lead, copper, tin, silver and gold.
Bismuth has many uses. The most important ores are bismuthinite or bismuth glance and bismite. Peru, Japan, Mexico,and Canada are also major bismuth producers. Much of the bismuth produced in the U.S. is obtained as a by-product in refining lead, copper, tin, silver, and gold ores.
"Bismanol" is a permanent magnet of high coercive force, made of MnBi, by the U.S. Naval Surface Weapons Center. Bismuth expands 3.32% on solidification. This property makes bismuth alloys particularly suited to the making of sharp castings of objects subject to damage by high temperatures. With other metals such as tin, cadmium, etc., bismuth forms low-melting alloys which are extensively used for safety devices in fire detection and extinguishing systems. Bismuth is used in producing malleable irons and is finding use as a catalyst for making acrylic fibers. When bismuth is heated in air it burns with a blue flame, forming yellow fumes of the oxide. The metal is also used as a thermocoupling material, and has found application as a carrier for 235U or 233U fuel in nuclear reactors. Its soluble salts are characterized by forming unsoluble basic salts on the addition of water, a property sometimes used in detection work. Bismuth compounds are used as a pigment in paints and cosmetics.
Bismuth has been incorporated into semiconductor materials and Nanoparticles for a number of useful purposes.
Bismuth in medicine
Bismuth carbonate (Bi2(CO3)3) is used to treat diarrhea and gastric ulcers. Bismuth isotopes are used in medicine. The isotopes 212Bi and 213Bi (with half-lives of 1 h and 0.76 h, respectively) are both used in medicine for radioimmunotherapy as bismuth-labeled monoclonal antibodies to treat cancer cells from melanoma (skin cancer) and ovarian cancer. 212Bi has also been used for radioimmunotherapy of leukemia and for targeting the vascular endothelial cells (thin layer of simple squamous cells that forms the interface between circulating blood or lymph and the remainder of the vessel wall) of tumors.
Bismuth compounds are considered to be poorly to moderately absorbed following inhalation, topical application, or gastrointinal ingestion and depends on the water solubility of bismuth salts. The mechanism by which bismuth produces toxicity has not been identified. Symptoms of bismuth poisoning include fever, weakness, pain similar to rheumatism, and diarrhea.
Bismuth nephrotoxicity from injection of bismuth compounds has been known for many years . Bismuth has also been shown to induce the renal synthesis of the metal-binding protein metallothionein (MT). There does not appear to be an antidote of choice for bismuth toxicity in humans.