Physical and chemical characteristics:
There are two stable isotopes of element boron: 10B (atomic weight 10.0129) and 11b (atomic weight 11.00931). The low temperature is α type
Diamond crystal, high temperature β Rhombic crystal, tetragonal crystal and amorphous crystal. Different physical properties of forms are also different.
Relative density（ α Type) 2.46（ β Type) 2.35, (tetragonal crystal) 2.31, (amorphous) 2.35. Melting point 2190 ℃,
The boiling point is 3680 ℃. Vaporization heat 480kJ / mol, melting heat 50.2kj/mol, hardness 11, thermal conductivity (25 ℃) 27.4w / (m.k).
Insoluble in water, hydrochloric acid, ethanol and ether. Dissolve in cold concentrated lye and release hydrogen. It can be oxidized by concentrated nitric acid and concentrated sulfuric acid
Boric acid. At high temperature, it can interact with oxygen, nitrogen, ammonia, sulfur, halogen and carbon to form various compounds, and can also directly combine with many metals,
It can also react with organic compounds to form organic borides. In hydrogen reaction, it can form a series of covalent hydrides boranes.
Amorphous boron powder is a kind of dark brown powder, tasteless and odorless. Its chemical properties are relatively active. It is stable in air and room temperature. When heated to 300 ℃
When it is oxidized and reaches 700 ℃, it will catch fire, and the micro gasified boron flame is green. Crystalline boron is black gray. It is a hard and brittle solid with metallic luster,
It is more stable than amorphous boron. Elemental boron is easily absorbed by intestine and skin. The poisoning phenomenon is manifested in skin rash and inhibition of central nervous system.
(1) Fireworks industry: explosive initiator, boron flame is green.
(2) Rocket and missile fuel rich propellant.
(3) Nuclear industry: neutron counter tube, neutron absorber, reactor control rod.
(4) Automobile airbag: initiator.
(5) Powder metallurgy additive, thermal spraying surface coating.
(6) Metallurgy: smelting of gas scavenger and special steel.
(7) Semiconductor industry: doped elements.
(8) Pharmaceutical industry and organic synthesis: catalysts.
(9) Synthetic boride: boron containing functional ceramics, boride superconductors, etc.
(10) Glass industry.
(11) Electronic industry: pilot electrode (cathode material) of pilot tube.
(12) Welding powder: an important department of weapons welding.
Matters needing attention:
△ safety instructions: This product is poisonous by inhalation and ingestion. Inhalation affects the central nervous system, and ingestion causes gastrointestinal irritation and boron poisoning, skin and eye contact cause mild irritation. Wear safety goggles, dust mask and rubber gloves during operation.
△ product packaging: vacuum packaging, aluminum platinum bag lined with plastic bag. The net weight of each bag is 1kg.
△ storage method: store in a cool, ventilated and dry warehouse. The shelf life is 12 months, and it can still be used if it is qualified after re inspection.
△ product transportation: avoid violent collision, rain and exposure during transportation, and do not mix with strong oxidants.
△ others: in order to meet the needs of customers, the company can develop and develop products according to the special needs of customers.
Note: the elemental boron is black or dark brown powder. During oxidation in air, the formation of boron trioxide film hinders the continuous oxidation of internal boron and amorphous boration
Lively in nature. Powder and air can form explosive mixture. Boron anhydride was reduced with magnesium to produce amorphous boron.
Technical index standard of boron powder