Chemical Properties
Bismuth is a white, crystalline, brittle metal with a pinkish tinge. Bismuth is the most
diamagnetic of all metals, and its thermal conductivity is lower than any metal. It
occurs naturally in the metallic state and in minerals such as bismite. The most important ores are bismuthinite or bismuth glance and bismite, and countries such as Peru, Japan, Mexico, Bolivia, and Canada are major producers of bismuth. It is found as crystals in the sulfi de ores of nickel, cobalt, silver, and tin. Bismuth is mainly produced as a
by-product from lead and copper smelting. It is insoluble in hot or cold water. Bismuth
explodes if mixed with chloric or perchloric acid. Molten bismuth explodes and bismuth powder glows red-hot on contact with concentrated nitric acid. It is flammable in
powder form.
Bismuth is used in the manufacture of low melting solders and fusible alloys, as key
components of thermoelectric safety appliances, such as automatic shut offs for gas and
electric water heating systems and safety plugs in compressed gas cylinders, in the production of shot and shotguns, in pharmaceuticals, in the manufacture of acrylonitrile,
the starting material for synthetic fi bers and rubbers. Bismuth oxychloride is sometimes
used in cosmetics. Also bismuth subnitrate and bismuth subcarbonate are used in medicine. Bismuth subsalicylate is used as an antidiarrheal and to treat other gastrointestinal
diseases.
Health Hazard
Exposures to bismuth salts are associated primarily by ingestion. Bismuth is known to
cause adverse health effects. The symptoms include, but are not limited to, irritation
of the eyes, skin, respiratory tract, lungs, foul breath, metallic taste, and gingivitis.
On ingestion, bismuth causes nausea, loss of appetite, weight, malaise, albuminuria,
diarrhea, skin reactions, stomatitis, headache, fever, sleeplessness, depression, rheumatic pain, and a black line may form on gums in the mouth due to deposition of
bismuth sulfi de. Prolonged exposure to bismuth causes mild but deleterious effects
on the kidneys and high concentrations of bismuth result in fatalities. Occupational
exposures to bismuth occur during the manufacture of cosmetics, industrial chemicals, and pharmaceuticals. Acute exposure with over dosage of bismuth-containing
drugs causes anorexia, nausea, vomiting, abdominal pain, and possibly a dry mouth
and thirst. Bismuth also causes neurotoxicity. Bismuth pentafl uoride is highly toxic
and causes irritation to the skin, eyes, and respiratory tract, while bismuth subnitrate
causes blurred vision.
Potential Exposure
Bismuth is used as a constituent of
tempering baths for steel alloys; in low Freezing/Melting
point alloys which expand on cooling; in aluminum and
steel alloys to increase machinability; and in printing type
metal. Bismuth compounds are found primarily in pharmaceuticals
as antiseptics, antacids, antiluetics, and as a
medicament in the treatment of acute angina. They are also
used as a contrast medium in roentgenoscopy and in cosmetics.
For the general population the total intake from food
is 5 20 μg with much smaller amounts contributed by air
and water.
First aid
If this chemical gets into the eyes, remove any
contact lenses at once and irrigate immediately for at least
15 minutes, occasionally lifting upper and lower lids. Seek
medical attention immediately. If this chemical contacts the
skin, remove contaminated clothing and wash immediately
with soap and water. Seek medical attention immediately.
If this chemical has been inhaled, remove from exposure,
begin rescue breathing (using universal precautions, including
resuscitation mask) if breathing has stopped and CPR if
heart action has stopped. Transfer promptly to a medical
facility. When this chemical has been swallowed, get medical
attention. Give large quantities of water and induce
vomiting. Do not make an unconscious person vomit. Note:
Dimercaptol (BAL) brings good results in the treatment of
bismuth poisoning if given early. Other measures include
atropine and meperidine to relieve gastrointestinal discomfort.
Shipping
UN3089 Metal powders, flammable, n.o.s.,
Hazard Class: 4.1; Labels: 4.1—Flammable solid.
Incompatibilities
Finely divided powder is highly flammable.
Reacts with strong acids and strong oxidizers, chlorine,
fused ammonium nitrates, iodine pentafluoride, and nitrosyl
fluoride.
Waste Disposal
Dissolve in a minimum
amount of concentrated HCl. Dilute with water until precipitate
is formed. Redissolve in HCl. Then saturate with
H2S. Filter, wash, dry and return to supplier.
Physical properties
Bismuth has unusually low toxicity for a heavy metal.
Bismuth is stable to both dry and moist air at ordinary
temperatures. When red hot, it reacts with water to
make bismuth(III) oxide. Bismuth forms trivalent and
pentavalent compounds. The trivalent compounds are
more common. Many of its chemical properties are
similar to those of As and Sb, although they are less toxic
than derivatives of those lighter elements. At elevated
temperatures, the vapors of the metal combine rapidly
with oxygen, forming the yellow trioxide, Bi2O3.
Isotopes
There are a total of 59 radioactive isotopes for bismuth, ranging in half-livesfrom a few milliseconds to thousands of years. At one time it was thought that there wasjust one stable isotope (Bi-209), but it was later found that Bi-209 is radioactive witha half-life of 19,000,000,000,000,000,000 years. Such a long half-life means that Bi-209 has not completely disintegrated and is still found in nature, and is thus consideredstable. In this case, Bi-209 makes up 100% of Bismuth’s natural abundance.
Origin of Name
Bismuth was known and used by the ancient alchemists along with
other metals both for chemical reactions and for medical purposes. The name comes
from the German bismu, which had been changed from wismu, meaning “white.”
Occurrence
Bismuth is the 70th most abundant element, and it is widely spread over the Earth’s crust, butin very small amounts. There are no major concentrated sources. It occurs both in the free elementalstate and in several ores. The major ore, bismuthinite (B2S3), is found in South America.
The United States gets most of its bismuth as a by-product from smelting ores of lead,silver, copper, and gold. It is also recovered from the refining of tin and tungsten ores.
Characteristics
Bismuth is more resistant to electrical current in its solid state than it is in its liquid form.Its thermal conductivity is the lowest of all metals, except mercury. Even though it is considereda metal-like element, it is a very poor conductor of heat and electricity.
Bismuth has a characteristic similar to water. It expands when changing from the liquidphase to the solid phase. This factor makes it useful as an alloy in metals that are used to fillmolds, given that it will expand to the cast’s dimensions.
Uses
Bismuth is used to make the drugs such as Pepto-Bismol for upset stomachs and diarrheaand in medicine to treat intestinal infections. Bismuth is used in the cosmetics industry toprovide the “shine” for lipsticks, eye shadow, and other products.
It is added to steel and other metals as an alloy to make the metals easier to roll, press, pullinto wires, and turn on a lathe. It is also used in the semiconductor industry and to makepermanent magnets.
Bismuth is similar to antimony in that it expands from the molten liquid state to the solidstate. This property makes it an excellent material to pour into molds and can produce finedetails in whatever is being molded, such as metallic printing type and similar fine castings.
Uses
Several bismuth compounds have been used medicinally.
Some are used for gastrointestinal distress (Pepto-Bismol
contains bismuth subsalicylate). Others are used as salves and,
in rare cases, for treatment of parasites. In the past, bismuth was
also used to treat syphilis and malaria.
Commercially, bismuth is also used in the manufacture of
permanent magnets, semiconductors, and thermoelectric
materials; as a catalyst in making acrylonitrile; and as an
additive to improve the machinability of steels and other
metals.
Bismuth is also frequently used in cosmetics, generally nail
polish and lipstick.
Definition
A brittle pinkish metallic element belonging to group 15 (formerly VA) of the periodic table. It occurs native and in the ores Bi2S3 and Bi2O3. The element does not react with oxygen or water under normal temperatures. It can be dissolved by concentrated nitric acid. Bismuth is widely used in alloys, especially low-melting alloys. The element has the property of expanding when it solidifies. Compounds of bismuth are used in cosmetics and medicines.
Definition
bismuth: Symbol Bi. A white crystallinemetal with a pinkish tinge belongingto group 15 (formerly VB) ofthe periodic table; a.n. 83; r.a.m.208.98; r.d. 9.78; m.p. 271.3°C; b.p.1560°C. The most important ores arebismuthinite (Bi2S3) and bismite(Bi2S3). Peru, Japan, Mexico, Bolivia,and Canada are major producers. Themetal is extracted by carbon reductionof its oxide. Bismuth is the mostdiamagnetic of all metals and itsthermal conductivity is lower thanany metal except mercury. The metalhas a high electrical resistance and ahigh Hall effect when placed in magneticfields. It is used to make lowmelting-point casting alloys with tinand cadmium. These alloys expandon solidification to give clear replicationof intricate features. It is alsoused to make thermally activatedsafety devices for fire-detection andsprinkler systems. More recent applicationsinclude its use as a catalystfor making acrylic fibres, as a constituentof malleable iron, as a carrierof uranium–235 fuel in nuclearreactors, and as a specialized thermocouplematerial. Bismuth compounds(when lead-free) are used for cosmeticsand medical preparations. It is attackedby oxidizing acids, steam (athigh temperatures), and by moisthalogens. It burns in air with a blueflame to produce yellow oxide fumes.C. G. Junine first demonstrated that itwas different from lead in 1753.
Production Methods
Bismuth is obtained as a by-product in smelting and refining of lead, copper or tungsten ores. The metal is partially volatilized when the ore is smelted at the high temperature. Separation from copper is achieved by electrolytic refining, bismuth accumulating in the anode slimes with lead, arsenic, antimony, tellurium, and other metal impurities. All throughout the smelting and refining operations bismuth accompanies lead. It finally is removed from lead by Betterton-Kroll or Betts processes. The Betterton-Kroll process involves the addition of calcium-lead alloy or magnesium metal to lead slime, thus converting bismuth to high-melting bismuthides of calcium or magnesium, Ca3Bi2 or Mg3Bi2, respectively. These bismuthides liquate from the bath and are separated as dross. Bismuth dross is then melted in kettles forming Bi7Mg6K9 which liquates to the top of the bath and is removed from the molten lead. Treatments with caustic soda finally produce the high quality bismuth.
In a modified process, potassium substitutes for calcium to form Bi7Mg6Ca9 which liquates to the top of the bath and is removed from the molten lead. The Betts process is based on electrolytic refining using a solution of lead fluorosilicate and fluorosilicic acid. While lead is deposited on the cathode, bismuth goes to the anode where it is collected with other impurity metals. It is then filtered, dried, smelted, and further refined, depending on the purity desired. Impurities are removed by adding molten caustic and zinc, and finally by chlorination.
Bismuth may be obtained from other ores, too. The recovery process however, depends primarily on the chemical nature of the ores. For example, the sulfide ore requires smelting, carbon reduction, and the addition of iron (to decompose any bismuth sulfide present). Oxide ores, on the other hand, are treated with hydrochloric acid to leach bismuth from the mineral. The bismuth chloride solution is then diluted with water to precipitate bismuth oxy-chloride. The precipitate is roasted with lime and charcoal. Satisfactory recovery of the metal from its carbonate ore may be achieved by both the above techniques.
Bismuth is sold in the form of rod, lump, powder, and wire.
General Description
All foils are mounted on a permanent support which cannot be removed without damaging the foil.
Hazard
Bismuth is flammable as a powder. The halogen compounds of bismuth are toxic wheninhaled or ingested. Some of the salts of bismuth can cause metallic poisoning in a mannersimilar to mercury and lead.
At the beginning of the twentieth century, before penicillin, bismuth compounds wereused to treat some venereal diseases. However, the treatment was generally unsuccessful.
Flammability and Explosibility
Nonflammable
Industrial uses
Bismuth (symbol Bi) is a brittle, crystallinemetal with a high metallic luster with a distinctivepinkish tinge. The metal is easily cast butnot readily formed by working. Within a narrowrange of temperature, around 225°C, it can beextruded. Its crystal structure is rhombohedral.It is one of the few metals that expand onsolidification; the expansion is 3.3%. The thermalconductivity of bismuth is lower than thatof any metal, with the exception of mercury.Bismuth is the most diamagnetic of all metals(mass susceptibility of –1.35×106). It showsthe greatest Hall effect (increase in resistanceunder influence of a magnetic field). It also hasa low capture cross section for thermal neutrons(0.034 barn).
Bismuth is playing an important role innuclear research. Its high density gives it excellentshielding properties for gamma rays whileits low thermal neutron capture cross sectionallows the neutrons to pass through. For investigationsin which it is desired to irradiateobjects, i.e., animals, with neutrons but protectthem from gamma rays, castings of bismuth areused as neutron windows in nuclear reactors.Bismuth has been proposed as a solventcoolantsystem for nuclear power reactors. Thebismuth dissolves sufficient uranium so that,when the solvent and solute are pumpedthrough a moderator (graphite), criticality isreached and fission takes place. The heat generatedfrom the fission reaction raises the temperatureof the bismuth. The heated bismuth isthen pumped to conventional heat exchangersproducing the steam power required for eventualconversion to electricity.
Carcinogenicity
An old lifetime study with rats fed 2% bismuth subcarbonate (BSC) in the diet did not show an increase of tumors or a decrease of survival.
Environmental Fate
The mechanism by which bismuth produces toxicity has not
been identified. Interaction with thiol compounds has been
proposed as a primary mechanism.
storage
Color Code—Green: General storage may be used.
Purification Methods
Melt it in an atmosphere of dry helium, then filter through dry Pyrex wool to remove any bismuth oxide present [Mayer et al. J Phys Chem 64 238 1960].
Structure and conformation
The space lattice of Bi belongs to the trigonal system, and its arsenic type structure has lattice constants of a=0.4736 nm, Bi–Bi=0.310 nm, α=57°16', and u=0.474.
Toxicity evaluation
In aerated water, bismuth oxidizes; however, in an anaerobic
aqueous environment, bismuth is unaffected. Similarly, in the
atmosphere, bismuth is unaffected unless condensation or
deposition of water occurs.
Due to the inability for air and water to affect bismuth
under most circumstances, bismuth tends to persist until wet or
dry deposition, and therefore long-range transport is possible
and likely.
