Berylliumfluorid Chemische Eigenschaften,Einsatz,Produktion Methoden
ERSCHEINUNGSBILD
FARBLOSE STüCKE.
CHEMISCHE GEFAHREN
Reagiert mit starken S?uren.
ARBEITSPLATZGRENZWERTE
TLV: (als Be) 0.002 mg/m?(als TWA); 0.01 mg/m?(als STEL); Krebskategorie A1(best?tigte krebserzeugende Wirkung beim Menschen); Beabsichtigte ?nderung; 0,00005 mg/m?als TWA; 0,0002 mg/m?as STEL; Hautresorption Sensibilisierung Krebskategorie A1(best?tigte krebserzeugende Wirkung beim Menschen); (ACGIH 2008).
MAK: Sensibilisierung der Atemwege und der Haut; Krebserzeugend Kategorie 1 (DFG 2008).
AUFNAHMEWEGE
Aufnahme in den K?rper durch Inhalation des Aerosols und durch Verschlucken.
INHALATIONSGEFAHREN
Verdampfung bei 20°C vernachl?ssigbar; eine gesundheitssch?dliche Partikelkonzentration in der Luft kann jedoch beim Dispergieren schnell erreicht werden.
WIRKUNGEN BEI KURZZEITEXPOSITION
WIRKUNGEN BEI KURZZEITEXPOSITION: Die Substanz reizt stark die Augen, die Haut und die Atemwege. Inhalation von Staub oder Rauchen kann zu chemischer Pneumonie führen. Die Auswirkungen treten u.U. verz?gert ein. ?rztliche Beobachtung notwendig. Exposition kann zum Tod führen.
WIRKUNGEN NACH WIEDERHOLTER ODER LANGZEITEXPOSITION
Wiederholter oder andauernder Hautkontakt kann zu Hautsensibilisierung führen. Risiko der Lungensch?digung bei wiederholter oder l?ngerer Exposition. Führt zu chronischer Berylliose (Husten, Gewichtsverlust, Schw?che). Krebserzeugend für den Menschen.
LECKAGE
Verschüttetes Material in abdichtbaren Beh?ltern sammeln; falls erforderlich durch Anfeuchten Staubentwicklung verhindern. Reste sorgf?ltig sammeln. An sicheren Ort bringen. NICHT in die Umwelt gelangen lassen. Chemikalienschutzanzug mit umgebungsluftunabh?ngigem Atemschutzger?t.
R-S?tze Betriebsanweisung:
R51/53:Giftig für Wasserorganismen, kann in Gew?ssern l?ngerfristig sch?dliche Wirkungen haben.
R49:Kann Krebs erzeugen beim Einatmen.
R48/23:Giftig: Gefahr ernster Gesundheitssch?den bei l?ngerer Exposition durch Einatmen.
R43:Sensibilisierung durch Hautkontakt m?glich.
R36/37/38:Reizt die Augen, die Atmungsorgane und die Haut.
R26:Sehr giftig beim Einatmen.
R25:Giftig beim Verschlucken.
S-S?tze Betriebsanweisung:
S61:Freisetzung in die Umwelt vermeiden. Besondere Anweisungen einholen/Sicherheitsdatenblatt zu Rate ziehen.
S53:Exposition vermeiden - vor Gebrauch besondere Anweisungen einholen.
S45:Bei Unfall oder Unwohlsein sofort Arzt zuziehen (wenn m?glich, dieses Etikett vorzeigen).
Beschreibung
Beryllium fluoride has the formula, BeF2, and is
a hygroscopic, amorphous solid with a melting point
of 800°C. It is soluble in water and is used in beryllium
metallurgy in which the metal, Be, is employed as an
alloy. Solid crystalline BeF2 has a silica-like structure with
beryllium in a four-coordinate position.
Chemische Eigenschaften
Beryllium fluoride is readily soluble in water, dissolving in its own water of hydration as BeF2·2H2O. The compound cannot be crystallized from solution and is prepared by thermal decomposition of ammonium fluoberyllate, (NH4)2BeF4.
Physikalische Eigenschaften
Glassy solid; tetragonal crystal system; hygroscopic; density 2.1 g/cm
3; melts BERYLLIUM FLUORIDE 101 at 552°C; vaporizes at 1,169°C; very soluble in water; sparingly soluble in alcohol.
Verwenden
Beryllium fluoride is used in biochemistry, particularly protein crystallography, since it binds in some of the same ways as phosphate does in human tissues. ADP and beryllium fluoride together tend to bind to ATP sites and inhibit protein action, making it possible to crystallize proteins in the bound state. Beryllium fluoride forms a basic constituent of the preferred fluoride salt mixture used in liquid-fluoride nuclear reactors. Typically, beryllium fluoride is mixed with LiF to form a base solvent, into which fluorides of uranium and thorium are introduced. Beryllium fluoride is exceptionally chemically stable and LiF/BeF2 mixtures have low melting points and the best neutronic properties of any of the fluoride salt combinations appropriate for reactor use.
Definition
ChEBI: The fluoride salt of beryllium (+2 oxidation state). In the solid state it exists as a glass, with four-coordinate Be2+ tetrahedral centres and two-coordinate fluoride centres. As a gas it adopts a linear triatomic structure and in the
liquid state a fluctuating tetrahedral structure. In protein crystallography it is used as a mimic of phosphate.
synthetische
Beryllium fluoride is made by thermal decomposition of ammonium beryllium fluoride at 900 to 950°C.
Manufacturing Process
First, beryllium hydroxide is dissolved in an ammonium hydrogen fluoride solution. The resulting ammonium tetrafluoroberyllate is dissociated to a small extent in the solution that the pH can be varied over a wide range without precipitating beryllium hydroxide. Impurities can thus be precipitated relatively easily as hydroxides. Aluminum is precipitated as hydroxide by increasing the pH to 8.3. Chromium and manganese are precipitated by oxidation with lead dioxide, and manganese is precipitated by oxidation with lead dioxide and manganese dioxide. Copper, nickel, and lead are precipitated as sulfides. Ammonium tetrafluoroberyllate is freely soluble in water. When concentrated by evaporation, it crystallizes without water or hydration. Above 130 ?C, it dissociates into ammonium fluoride and beryllium fluoride. Between 900 and 1100 ?C, ammonium tetrafluoroberyllate dissociates into gaseous beryllium fluoride and gaseous ammonium fluoride. The latter can be recycled into the process as ammonium hydrogen fluoride by dissolving it in aqueous hydrogen fluoride. Cooling produces beryllium fluoride as vitreous grains.
Allgemeine Beschreibung
Odorless white solid. Denser than water.
Air & Water Reaktionen
Water soluble.
Reaktivit?t anzeigen
Beryllium fluoride is incompatible with the following: Acids, caustics, chlorinated hydrocarbons, oxidizers, magnesium, molten lithium .
Hazard
A known carcinogen. Toxic by inhalation and ingestion.
Health Hazard
Any dramatic weight loss should be considered as possible first indication of beryllium disease. Inhalation causes irritation of nose, throat, and lungs, severe pneumonitis, and/or pulmonary edema. Ingestion causes fatigue, weakness, loss of appetite. Contact with eyes causes severe irritation and burns. Contact with skin causes dermatitis and non-healing ulcers.
Brandgefahr
Special Hazards of Combustion Products: Toxic and irritating vapor of unburned material may form in fire.
Sicherheitsprofil
Confirmed carcinogen withexperimental carcinogenic and tumorigenic data byinhalation. Poison by ingestion, subcutaneous,intravenous, and intraperitoneal routes. Incompatible with Mg. When heated to decomposition, itemits very toxic fumes of BeO and F
Berylliumfluorid Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
