Chemical Properties
Antimony is a silvery-white metal found in the earth’s crust. It is insoluble in hot or
cold water, but soluble in hot concentrated sulfuric acid and hot nitric acid, and reacts
with oxidizing acids and halogens (fl uorine, chlorine, or bromine). It does not react with
water at room temperature, but will ignite and burn in air at higher temperatures. Ores
of antimony are mined and later mixed with other metals to form antimony alloys,
which are used in lead storage batteries, solder, sheet and pipe metal, bearings, castings, and pewter. Antimony oxide is added to textiles and plastics to prevent them from
catching fi re. It is also used in paints, ceramics, and fi reworks, and as enamels for plastics, metal, and glass. Antimony is alloyed with other metals, such as lead, to increase
its hardness and strength; its primary use is in antimonial lead, which is used in grid
metal for lead acid storage batteries. Antimony salts are used in the treatment of leishmaniasis and schistosomiasis.
General Description
A silvery or gray solid in the form of dust. Denser than water and insoluble in water. Toxic by inhalation and by ingestion. May burn and emit toxic fumes if heated or exposed to flames. Used to make electric storage batteries and semiconductors.
Reactivity Profile
ANTIMONY is spontaneously flammable in fluorine, chlorine, and bromine. With iodine, the reaction produces heat, which can cause flame or even an explosion if the quantities are great enough [Mellor 9:379 1946-47]. Even at 10° C. bromine trifluoride reacts with antimony incandescently. Bromine trifluoride reacts similarly with arsenic, boron, bromine, iodine, phosphorus, and sulfur [Mellor 2:113 1946-47]. Bromoazide explodes on contact with antimony, arsenic, phosphorus, silver foil, or sodium. ANTIMONY POWDER(7440-36-0) is very shock sensitive. Explosions of chloric acid have been due to the formation of unstable compounds with antimony, bismuth, ammonia, and organic matter [Chem. Abst. 46:2805e 1952]. The reaction of finely divided antimony and nitric acid can be violent [Pascal 10:504 1931-34]. Powdered antimony mixed with potassium nitrate explodes when heated [Mellor 9:282 1946-47]. When antimony or arsenic and solid potassium permanganate are ground together, the metals ignite [Mellor 12:322 1946-47]. Sodium peroxide oxidizes antimony, arsenic, copper, potassium, tin, and zinc with incandescence [Mellor 2:490-93 1946-47].
Air & Water Reactions
Insoluble in water.
Hazard
Use with adequate ventilation. Soluble salts
are toxic.
Health Hazard
Oxides from metallic fires are a severe health hazard. Inhalation or contact with substance or decomposition products may cause severe injury or death. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may cause pollution.
Health Hazard
The toxicity of antimony compounds is comparable to that of arsenic, but as antimony
compounds are hardly absorbed in the gastrointestinal tract, there is less hazard of acute
poisoning. In addition, antimony compounds often cause vomiting, thus being removed
from the organism. Chronic poisoning may result in damage to the liver, kidneys, and
even the heart and the circulatory system. The symptoms differ among the compounds.
Stibine accumulates in fatty tissue. Exposures to antimony and its compounds cause
poisoning and toxicity to the worker with symptoms that include, but are not limited to,
irritation to eyes, skin, nose, and throat, ulceration of nasal septum and larynx, dermatitis as characterized by antimony spots, cough, dizziness, seizures, headache, anorexia,
nausea, vomiting, diarrhea, stomach cramps, bloody stools, insomnia, inability to smell
properly, metallic taste, cardiovascular disturbances, pulmonary edema, pharyngitis,
tracheitis, heart and lung damage, pneumoconiosis, slow and shallow respiration, coma,
and death. Antimony fumes and dusts inhaled by occupational workers are associated
with the development of benign tumors of the lungs, dermatitis and, less commonly,
effects on the heart and kidneys. Laboratory animals exposed to antimony by inhalation or ingestion exhibit effects similar to those noted in humans. Antimony can be
measured in the urine, feces, and blood. To date, little is known about the environmental
risks involved. Water pollution seldom occurs because of the low solubility of most compounds. Extreme caution should be taken when coming into direct contact with antimony compounds.
Potential Exposure
Exposure to antimony may occur during
mining, smelting or refining; alloy and abrasive manufacture;
and typesetting in printing. Antimony is widely
used in the production of alloys, imparting increased hardness,
mechanical strength, corrosion resistance, and a low
coefficient of friction. Some of the important alloys are
Babbitt, pewter, white metal, Britannia metal and bearing
metal (which are used in bearing shells), printing-type,
metal, storage battery plates, cable sheathing, solder, ornamental
castings, and ammunition. Pure antimony compounds
are used as abrasives, pigments, flame-proofing
compounds, plasticizers, and catalysts in organic synthesis;
they are also used in the manufacture of tartar emetic,
paints, lacquers, glass, pottery, enamels, glazes, pharmaceuticals,
pyrotechnics, matches, and explosives. In addition,
they are used in dyeing, for blueing steel; and in coloring
aluminum pewter; and zinc. A highly toxic gas, stibine,
may be released from the metal under certain conditions.
Fire Hazard
May react violently or explosively on contact with water. Some are transported in flammable liquids. May be ignited by friction, heat, sparks or flames. Some of these materials will burn with intense heat. Dusts or fumes may form explosive mixtures in air. Containers may explode when heated. May re-ignite after fire is extinguished.
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.
Shipping
UN2871 Antimony powder, Hazard Class: 6.1;
Labels: 6.1-Poisonous materials.
Incompatibilities
Pyrophoric. Finely dispersed powder
may form explosive mixture in air. Strong oxidizers; strong
acids , produce a violent
reaction, and deadly stibine gas (antimony hydride). Heat
forms stibine gas. Mixtures with nitrates or halogenated
compounds may cause combustion. Forms an explosive
mixture with chloric and perchloric acid. Note: Stibine is
formed when antimony is exposed to nascent (freshly
formed) hydrogen.
Waste Disposal
Recovery and recycling is an
option to disposal which should be considered for scrap antimony
and spent catalysts containing antimony. Dissolve
spilled material in minimum amount of concentrated HCl.
Add water, until white precipitate appears. Then acidify to dissolve
again. Saturate with H2S. Filter, wash and dry
the precipitate and return to supplier. Consult with environmental
regulatory agencies for guidance on acceptable disposal
practices. Generators of waste containing this contaminant
(≥100 kg/mo) must conform with EPA regulations governing
storage, transportation, treatment, and waste disposal.
Physical properties
Physically, antimony’s properties are related to sulfur and some of the nonmetals, butchemically, its properties are related to metals. It behaves like a metal and is often found innature along with other metals. In its pure form it is rather hard and brittle with a grayishcrystal structure.
Isotopes
There are 53 isotopes of antimony. They range from Sb-103 to Sb-139 (a fewhave two forms). Their half-lives range from 150 nanoseconds to 2.7 years. The twostable isotopes of antimony and their contribution to the natural abundance of antimonyon Earth are as follows: Sb-121 = 57.21% and Sb-123 = 42.79%.
Origin of Name
The element’s name comes from the Greek words anti and minos,
which mean “not alone,” and antimony’s symbol (Sb) is derived from the name for its
ancient source mineral, stibnium.
Occurrence
Although antimony is not a rare metal, it is not well known, despite having been knownand used for many centuries. It is the 63rd most abundant element on Earth, and it occursmainly as sulfide ores or in combination with the ores of other metals. The ore that is theprimary source of antimony is the mineral stibnite (antimony sulfide, Sb2S3). Antimony is alsofound in copper, silver, and lead ores. Breithauptite (NiSb) and ullmanite (NiSbS) are twoores containing nickel. Dicrasite (Ag2Sb) and pyrargyrite (Ag3SbS3) are silver ores containingsome antimony.
Characteristics
There are two allotropes of antimony. The native metallic form is one allotrope, and theother allotrope is an amorphous grayish form. Antimony is a true metalloid that is brittle witha low melting point. And similar to nonmetals, it is a poor conductor of heat and electricity.
Antimony is unique in that when it solidifies from a molten liquid state to a solid state, itexpands, which is just the opposite of most metals. This is useful in making some typesettingcastings in which the expansion assures an accurate reproduction of the letter mold.
Application
It is important as wire materials of the thermocouples for spectroscopic measurements. The alloy with other metal is used because the material is fragile.
Definition
antimony: Symbol Sb. An elementbelonging to group 15 (formerly VB)of the periodic table; a.n. 51; r.a.m.121.75; r.d. 6.68; m.p. 630.5°C; b.p.1750°C. Antimony has several allotropes.The stable form is a bluishwhitemetal. Yellow antimony andblack antimony are unstable nonmetallicallotropes made at low temperatures.The main source isstibnite (Sb2S3), from which antimonyis extracted by reduction withiron metal or by roasting (to give theoxide) followed by reduction withcarbon and sodium carbonate. Themain use of the metal is as an alloyingagent in lead-accumulator plates,type metals, bearing alloys, solders,Britannia metal, and pewter. It is alsoan agent for producing pearlitic castiron. Its compounds are used inflame-proofing, paints, ceramics,enamels, glass dyestuffs, and rubbertechnology. The element will burn inair but is unaffected by water or diluteacids. It is attacked by oxidizingacids and by halogens. It was first reportedby Tholden in 1450.
Manufacturing Process
Antimony metal is recovered from ore primarily by pyrometallurgical techniques. Either antimony(III) sulfide is converted into the oxide, which is then reduced, or the ore is partially roasted and allowed to react with sulfide to form the metal and sulfur dioxide. Sulfide ores with antimony contents between 5 and 25% are roasted to give volatile Sb2O3, which is reduced directly to the metal. In many smelters mixed oxide – sulfide ores are processed in water-jacketed furnaces together with recycled material and byproducts containing antimony. Reverberatory furnaces are used mostly for reducing rich oxide materials.
Pharmaceutical Applications
Antimony presents itself
in a metallic grey form. Antimony is obtained from stibnite (Sb2S3) after reduction with iron.
Industrial uses
Antimony is a bluish-white metal, symbol Sb,with a crystalline scalelike structure that exhibitspoor electrical and heat conductivity. It isbrittle and easily reduced to powder. It is neithermalleable nor ductile and is used only in alloysor in its chemical compounds. Like arsenic andbismuth, it is sometimes referred to as a metalloid,but in mineralogy it is called a semimetal.The element is available commercially in99.999+% purity and is finding increasing usein semiconductor technology.
Antimony is produced either by roasting thesulfide with iron, or by roasting the sulfide andreducing the sublimate of Sb4O6 thus producedwith carbon; high-purity antimony is producedby electrolytic refining. Antimony is one of thefew elements that exhibits the unique propertyof expanding on solidification. Antimony isordinarily stable and not readily attacked by airor moisture. Under controlled conditions it willreact with O2 to form oxides. The chief uses ofantimony are in alloys, particularly for hardeninglead-base alloys.
Antimony imparts hardness and a smoothsurface to soft-metal alloys, and alloys containingantimony expand on cooling, thus reproducingthe fine details of the mold. This propertymakes it valuable for type metals. When alloyedwith lead, tin, and copper, it forms the babbittmetals used for machinery bearings. It is alsomuch used in white alloys for pewter utensils.Its compounds are used widely for pigments.
Carcinogenicity
Existing experimental data suggest that antimony may be an animal carcinogen, but there is
lack of data on the possible carcinogenic properties of antimony and antimony compounds for human exposures. The ACGIH refers to unpublished data on a large antimony smelter in the United Kingdom in the 1960s where workers were exposed to antimony trioxide ranging from 0.5 to 40mg/m3. The data may indicate increased mortality in lung cancer among the heavily exposed workers, but the workers were also exposed to zirconium making the data cited dif?cult to interpret.
Environmental Fate
The toxicity of Sb is a function of the water solubility and the
oxidation state of the Sb species under consideration. Antimony(
III) is generallymore toxic than antimony(V) and inorganic
forms are thought to be more toxic than organic forms. Stibane
gas (SbH3) when inhaled is the most toxic. Antimony toxicity
often parallels that of arsenic, although antimony salts are less
readily absorbed than arsenic. It is presumed that antimony, like
arsenic, complexes with sulfhydryl groups of essential enzymes
and other proteins. By analogy, antimony can uncouple oxidative
phosphorylation, which would inhibit the production of energy
necessary for cellular functions. Antimony’s trivalent compounds
are more toxic than its pentavalent compounds.
storage
Color Code—Blue: Health Hazard/Poison: Store ina secure poison location. Prior to working with this chemicalyou should be trained on its proper handling and storage.Store in tightly closed containers in a cool, well-ventilatedarea away from oxidizers, halogens, strong acids, and heat.Sources of ignition, such as smoking and open flames, areprohibited where this chemical is used, handled, or stored ina manner that could create a potential fire or explosion hazard. Contact with acids forms deadly stibine gas. Beforeentering confined space where this chemical may be present,check to make sure that an explosive concentration does notexist.
Structure and conformation
The space lattice of most stable metallic antimony (often called gray antimony) belongs to the hexagonal system, and its arsenic type structure (two atoms within a unit cell) has a lattice constant of a=0.449762 nm, a=57°6.6', u=0.233. Black antimony and yellow antimony are known, but these are unstable and transform to metallic antimony
Toxicity evaluation
Antimony is found naturally in the Earth’s crust and can be
released into the environment as windblown dust or sea spray
or from volcanic eruptions or forest fires. However, the emission
of antimony into the environment is overwhelmingly the
result of human activity, with the emission of antimony
trioxide, tetroxide, and pentoxide forms being the most
significant. Antimony trioxide is emitted as a result of coal
burning, or with fly ash when antimony-containing ores are
smelted. Humans are exposed to low amounts of antimony
from the air, drinking water, and food contaminated with
soil. Antimony concentration in the atmosphere is thought to
be 1.4–55 ng m-3. The more water soluble forms of antimony
are very mobile in aqueous media while the less soluble forms
of antimony are found attached to particles of soil, clay, and
sediment in rivers and lakes. The concentration of antimony in
the Pacific Ocean was found to be 0.2 mg l-1 and in the Rhine
river at 0.1 μg l-1. The trivalent state of antimony is the form
most often released by anthropogenic activities. In terms of soil
concentrations, it was reported by a US Geological Survey to be
less than 1–8 ppm in soil, with an average of 0.48 ppm. Studies
have estimated an exposure of less than 5 mg day1 on average
from food and water and appears to be significantly higher
than exposure by inhalation.
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