BORON CARBIDE |
PRODUCT
IDENTIFICATION
|
CAS
NO. |
12011-54-0
(B-C) 12069-32-8 (B4-C) |
|
EINECS
NO. |
235-111-5 |
FORMULA |
CB4 |
MOL
WT. |
55.25 |
H.S.
CODE
|
|
TOXICITY |
|
SYNONYMS |
B4-C; Tetrabor;
|
SMILES |
|
CLASSIFICATION
|
|
PHYSICAL
AND CHEMICAL PROPERTIES
|
PHYSICAL
STATE |
black
powder |
MELTING
POINT |
2350
C |
BOILING
POINT |
|
SPECIFIC
GRAVITY |
2.52 |
SOLUBILITY
IN WATER |
|
pH |
|
VAPOR
DENSITY |
|
AUTOIGNITION
|
|
NFPA
RATINGS
|
|
REFRACTIVE
INDEX
|
|
FLASH
POINT |
Not
considered to be a fire hazard |
STABILITY |
Stable
under ordinary conditions. |
APPLICATIONS
|
Boron carbide is a compound that contains boron and carbon, especially B4C; an
extremely hard, non-metallic, black crystalline compound or solid solution. Only
diamond is harder. In addition to its hardness property, boron carbide has the
physical properties of corrosion resistance, heat strength, low specific gravity
and high elastic modulus. It is used as an abrasive, neutron absorber for
nuclear reactors, and as an alloying agent in composite structural
materials. |
SALES
SPECIFICATION |
APPEARANCE
|
black
powder |
CB4 |
95.0%
min
|
TOTAL
B
|
78.0%
min
|
TOTAL
C
|
19.0%
min
|
MEAN
PARTICLE SIZE |
100
mesh, 325 mesh, 1000 grit |
FREE
C |
2.5%
max
|
B2O3 |
0.15%
max
|
Fe |
0.2%
max |
TRANSPORTATION |
PACKING |
|
HAZARD
CLASS |
Not
regulated |
UN
NO. |
|
OTHER
INFORMATION |
European
Hazard Symbols: XN, Risk Phrases: 20, Safety
Phrases: 22-36/37/39-38
|
GENERAL DESCRIPTION OF BORON AND ITS
COMPOUNDS |
Boron is a
nonmetallic element, group III in the periodic table. Symbol B; aomic number 5;
atomic mass 10.811; melting point ca 2,300 C; sublimation point ca 2,550 C;
specific gravity 2.37 or 2.34; valence +3; electronic config. [He]2s22p1. There
are two allotropes of boron; amorphous boron is a dark brown to black amorphous
powder, but metal-like crystalline solid is an extremely hard (9.3 on Mohs'
scale), black to silver-gray, brittle, lustrous and has a bad conductor in room
temperatures. The specific gravities of amorphous and crystalline forms are 2.37
and 2.34 respectively. The crystalline form is far less reactive than the
amorphous form. The amorphous powder is oxidized slowly in air at room
temperature and ignites spontaneously at high temperatures to form an oxide but
the crystalline form is oxidized only very slowly, even at higher temperatures.
Boron is widely distributed in the form of borates but is never found in the
elemental form in nature. The important commercial borate products are borax
penta (or deca) hydrate, boron oxide, sodium perborate, boric acid and minerals
are borax, colemanite, ulexite, tincal, kermite, and brines as well as
ascharite, hydroboracite, datolite, tourmaline, etc. The simple way to prepare
boron of amorphous powder form is the reduction of boron trioxide by heating
with magnesium. Boric acid is produced mainly from borate ores containing sodium
or calcium by the reaction with sulfuric acid in the presence of a hot aqueous
boric acid liquor to recycle.
Major end
uses for borates include;
- FIBERGLASS
AND GLASS : Boron fibers probide very high tensile strength and can be added to
plastics to make a material that is stronger than steel yet lighter than
aluminum. Boron is used primarily in fiberglass and boronsilicate glass which is
the strong heat-resistant glass that contains a minimum of 5 percent boric
oxide. The resistance to heat and chemical is attributable to the boric oxide
which replace for sodium oxide in the structure of the glass, creating low
thermal expansion. Replace for sodium oxide, Boric Oxide is a powerful base
offering a high quality of heat and chemical resistance. Boric compouds are
important components in optical glass industry to reduce thermal and mechanical
shocks but to increase chemical resistance and durability.
- CERAMICS :
Boric compounds reduce significantly the melting point and can be used as an
essential ingredient for the production of ceramic frits and borosilicate
glazes. Boric compounds are used to control the coefficient of expansion to
ensure that the glaze remains fixed with the body without crazing or distortion.
- AGRICULTURE
AND FERTILIZER: Boron is an essential micronutrient for plant growth. Boron
fertilizers mixed with other compounds or NPK fertilizers are useful
boron-deficient soils.
- FLAME
RETARDANT : Boron is an effective chemical flame retardant for an ample array of
products. It is also used for wood, plywood, textile products, cotton, paper and
cellulose.
- CORROSION
INHIBITOR : Different boric composition can be used as Corrosion Inhibitors and
anti-freeze (mixed with Ethylene Glycol in automobile motor cooling systems), as
well as in brewing, heat treating, hydraulic fluids, and treatment of metallic
products.
- WOOD
PRESERVATIVES and PESTICIDES : Borates and Boric Acid are very effective in
controlling and eliminating insects and fungi. Though they are not harmful to
mammals, they are toxic against cockroaches, ants, scarabs, larvae, and other
insects, resulting in manipulation at any location and environment.
- METALLURGY :
Boron is used as a sealing for non-ferrous metals and used as a deoxidizer and
degasifier in metallurgy. Because it absorbs neutrons. It is used in the
production of steel. Traces of Ferro boron in boric steel increase its strength.
Bron eliminates impurities metallurgist systems, resulting in highly pure
material to be used in electrical conductors especially.
- PHARMACEUTICALS AND COSMETICS : Boric Acid is
recognized for its application as a pH buffer and as a moderate antiseptic agent
and emulsifier. It is a component of ointments, mouth-washes, eye-drops, bath
salts, creams and shampoos. It can be
used for skin cooking sensation due to good thermal conductivity.
It is also known boron compounds made with all 10B
isotope selectively destroy cancer cell.
- NUCLEAR
APPLICATIONS : Boron is used in the shielding material, in neutron detection
and in some control rods of nuclear reactors as it absorbs
neutrons.
|
|