Beryllium Carbide Carbides

Beryllium Carbide. Beryllium carbide [506-66-17, Be2C, maybe prepared by heating a mixture of beryllium oxide and carbon to 1950—2000°C,... 

Beryllium carbide slowly hydroly2es to beryllium oxide and methane in the presence of atmospheric moisture although months may be requited to complete the reaction. Any carbon contained in beryllium metal is present as the carbide because the solubiUty of carbon in beryllium is extremely low. 

Saltlike Carbides. Almost all carbides of Groups 1—3 of the Periodic Table are saltlike. Beryllium carbide and Al C may be considered as derivatives of methane ion) and most carbides having C2 groups, ie, ions, as derivatives of acetylene. This is supported to some extent by hydrolysis reactions ... 

Diamondlike Carbides. SiUcon and boron carbides form diamondlike carbides beryllium carbide, having a high degree of hardness, can also be iacluded. These materials have electrical resistivity ia the range of semiconductors (qv), and the bonding is largely covalent. Diamond itself may be considered a carbide of carbon because of its chemical stmeture, although its conductivity is low. 

Dry hydrogen chloride gas readily attacks solid beryllium above about 500° C with the formation of volatile beryllium chloride. Beryllium carbide and nitride are similarly attacked, but not beryllium oxide this behaviour is of use in one method for the determination of beryllium-oxide in metallic beryllium. 

Beryllium carbide, Be, produced by the pyrolysis of metallo-organic compounds. 

Beryllium bromide, 3 663 physical properties of, 4 328 Beryllium carbide, 3 661-662 4 648,... 

Beryllium carbide (Be C) is used for the cores in nuclear reactors. 

Beryllium oxide Zirconium oxide Aluminum nitride Boron carbide Silicon carbide and nitride Tungsten carbide Beryllium carbide... 

Beryllium carbide is used in a nuclear reactor as core material. 

Beryllium carbide is prepared by heating the elements beryllium and carbon at elevated temperatures (above 900°C). It also may be prepared by reduction of beryllium oxide with carbon at a temperature above 1,500°C ... 

Beryllium carbide decomposes very slowly in water ... 

Whiskers (nonoxides) (aluminum nitride, boron carbide, silicon carbide, silicon nitride, tungsten carbide, beryllium carbide)... 

Total carbon in beryllium is determined by combustion of the sample, along with an accelerator mixture of tin, iron, and copper, in a stream of oxygen (15,16). The evolved carbon dioxide is usually measured by infrared absorption spectrometry. Beryllium carbide can be determined without interference from graphitic carbon by dissolution of the sample in a strong base. Beryllium carbide is converted to methane, which can be determined directly by gas chromatography. Alternatively, the evolved methane can be oxidized to carbon dioxide, which is determined gravimetrically (16). 

The crystal structure of beryllium carbide is cubic, density = 2.44 g/mL. The melting point is 2250—2400°C and the compound dissociates under vacuum at 2100°C (1). This compound is not used industrially, but Be2C is a potential first-wall material for fusion reactors, one on the very limited list of possible candidates (see Fusion energy). 

Beryllium Carbide, Be,C, yel or brn-yel crysts, d 1.9 at 15°. Was first prepd by heating beryllium oxide with carbon in an electric furnace (Ref 2). Other methods of prepn arej listed in Ref 1. Henry (Ref 3) established its formula as BeaC... 

Beryllium Carbide., See under Acetylides and Carbides A71-L Beryllium Diazide A524-R Binding Energy. See under Atomic Energy A5O0-R... 

---