Berylliumoxid Chemische Eigenschaften,Einsatz,Produktion Methoden
ERSCHEINUNGSBILD
WEISSE KRISTALLE ODER PULVER.
CHEMISCHE GEFAHREN
Beim Erhitzen bilden sich giftige Rauche.
ARBEITSPLATZGRENZWERTE
TLV: (als Be) 0.002 mg/m?(als TWA); 0.01 mg/m?(als STEL); Krebskategorie A1(bestätigte krebserzeugende Wirkung beim Menschen); Beabsichtigte änderung; 0,00005 mg/m?als TWA; 0,0002 mg/m?as STEL; Hautresorption Sensibilisierung Krebskategorie A1(bestätigte krebserzeugende Wirkung beim Menschen); (ACGIH 2008).
MAK: Sensibilisierung der Atemwege und der Haut; Krebserzeugend Kategorie 1 (DFG 2008).
AUFNAHMEWEGE
Aufnahme in den Körper durch Inhalation des Aerosols und durch Verschlucken.
INHALATIONSGEFAHREN
Verdampfung bei 20°C vernachlässigbar; eine gesundheitsschädliche Partikelkonzentration in der Luft kann jedoch beim Dispergieren schnell erreicht werden.
WIRKUNGEN BEI KURZZEITEXPOSITION
WIRKUNGEN BEI KURZZEITEXPOSITION: Die Substanz reizt die Augen, die Haut und die Atemwege. Inhalation von Staub kann zu chemischer Pneumonie führen. Die Auswirkungen treten u.U. verzögert ein. ärztliche Beobachtung notwendig. Exposition kann zum Tod führen.
WIRKUNGEN NACH WIEDERHOLTER ODER LANGZEITEXPOSITION
Wiederholter oder andauernder Hautkontakt kann zu Hautsensibilisierung führen. Risiko der Lungenschädigung bei wiederholter oder längerer Exposition. Führt zu chronischer Berylliose (Husten, Gewichtsverlust, Schwäche). Krebserzeugend für den Menschen.
LECKAGE
Verschüttetes Material in abdichtbaren Behältern sammeln; falls erforderlich durch Anfeuchten Staubentwicklung verhindern. Reste sorgfältig sammeln. An sicheren Ort bringen. NICHT in die Umwelt gelangen lassen. Chemikalienschutzanzug mit umgebungsluftunabhängigem Atemschutzgerät.
R-Sätze Betriebsanweisung:
R49:Kann Krebs erzeugen beim Einatmen.
R25:Giftig beim Verschlucken.
R26:Sehr giftig beim Einatmen.
R36/37/38:Reizt die Augen, die Atmungsorgane und die Haut.
R43:Sensibilisierung durch Hautkontakt möglich.
R48/23:Giftig: Gefahr ernster Gesundheitsschäden bei längerer Exposition durch Einatmen.
S-Sätze Betriebsanweisung:
S53:Exposition vermeiden - vor Gebrauch besondere Anweisungen einholen.
S45:Bei Unfall oder Unwohlsein sofort Arzt zuziehen (wenn möglich, dieses Etikett vorzeigen).
Beschreibung
Beryllium oxide
(BeO) is formed by the ignition of beryllium metal in an oxygen atmosphere. The resulting solid is colourless
and insoluble in water.
Physikalische Eigenschaften
In the transmittance and reflectance spectra of BeO, the main peak of the reflectance is located at 730 cm
-1and the small peak is located at 1050 cm
-1.The fundamental frequency of the lattice absorption is υ
0=700±10 cm
-1, according to the reflectance analysis.
Physikalische Eigenschaften
It is the only material with
diamond that combines both
excellent thermal shock
resistance, high electrical
resistivity, and high thermal
conductivity, and hence is used
for heat sinks in electronics.
Beryllia is very soluble in water,
but slowly in concentrated acids
and alkalis. Highly toxic.
Exhibits outstanding corrosion
resistance to liquid metals Li,
Na, Al, Ga, Pb, Ni, and Ir.
Readily attacked by molten
metals such as Be, Si, Ti, Zr, Nb,
Ta, Mo, and W. Maximum
service temperature 2400°C.
Physikalische Eigenschaften
Beryllium oxide (BeO) is a white crystalline oxide. It occurs in nature as the mineral “Bromellite”. Historically, beryllium oxide was called glucina or glucinium oxide. It is an electrical insulator and its thermal conductivity is such that it is higher than any other nonmetal except diamond, and actually exceeds that of some metals. Its high melting point leads to its use as a refractory.
Verwenden
Beryllium oxide is used in the manufacture of high-temperature refractory material and high-quality electrical porcelains, such as aircraft spark plugs and ultrahigh-frequency radar insulators. The high thermal conductivity of beryllium oxide and its good high- frequency electrical insulating properties find application in electrical and electronic fields.
Another use of beryllium oxide is as a slurry for coating graphite crucibles to insulate the graphite and to avoid contamination of melted alloys with carbon. Beryllium oxide crucibles are used where exceptionally high-purity or reactive metals are being melted. In the field of beryllium oxide ceramics, a type of beryllia has been developed that can be formed into custom shapes for electronic and microelectronic circuits. Beryllium oxide has a high thermal conductivity, equal to that of aluminum, and excellent insulating properties, which permits closer packing of semiconductor functions in silicon integrated circuits.
Definition
ChEBI: A beryllium molecular entity consisting of beryllium (+2 oxidation state) and oxide in the ratio 1:1. In the solid state, BeO adopts the hexagonal wurtzite structure form while in the vapour phase, it is present as discrete diatomic covalent molecules.
synthetische
Beryllium oxide can be prepared by calcining beryllium carbonate, dehydrating the hydroxide or igniting the metal with oxygen gas, as shown in the following reactions:
BeCO
3→BeO＋CO
2
Be(OH)
2→BeO＋H
2O
2Be＋O
2→2BeO
Igniting beryllium in air
Allgemeine Beschreibung
Odorless white solid. Sinks in water.
Air & Water Reaktionen
The amount of heat generated by hydrolysis may be large.
Reaktivität anzeigen
BERYLLIUM OXIDE is incompatible with the following: Acids, caustics, chlorinated hydrocarbons, oxidizers, molten lithium, magnesium .
Hazard
Highly toxic by inhalation. Keep container
tightly closed and flush out after use.
Health Hazard
Any dramatic, unexplained weight loss should be considered as possible first indication of beryllium disease. Other symptoms include anorexia, fatigue, weakness, malaise. Inhalation causes pneumonitis, nasopharyngitis, tracheobronchitis, dyspnea, chronic cough. Contact with dust causes conjunctival inflammation of eyes and irritation of skin.
Brandgefahr
Special Hazards of Combustion Products: Toxic BERYLLIUM OXIDE fume may form in fire.
Industrielle Verwendung
A colorless to white crystalline powder of the composition beryllium oxide, also called beryllia. It has a specific gravity of 3.025, a high melting point, about 2585 C, and a Knoop hardness of 2000. It is used for polishing hard metals and for making hot-pressed ceramic parts. Its high heat resistance and thermal conductivity make it useful for crucibles, and its high dielectric strength makes it suitable for high-frequency insulators. Single-crystal beryllia fibers, or whiskers, have a tensile strength above 6800 MPa.
Beryllium oxide is tapped for nuclear reactor service because of its refractoriness, high thermal conductivity, and ability to moderate (slow down) fast neutrons. The thermal neutrons that result are more efficient in causing fusion of uranium- 235. Nuclear industry uses for beryllia include reflectors and the matrix material for fuel elements. When mixed with suitable nuclear poisons, beryllium oxide may be a new candidate for shielding and control rod assembly applications.
Sicherheitsprofil
Confirmed carcinogen withexperimental tumorigenic data. Experimental teratogenicdata. Other experimental reproductive effects. Incompatible with (Mg +heat). When heated to decomposition it emits very toxicfumes of BeO.
Structure and conformation
The space lattice of Beryllium oxide belongs to the hexagonal system with lattice constants a=0.2698 nm and c=0.4380 nm.
Berylliumoxid Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
