Beryllium Oxide BeO

a compound of beryllium and oxygen; white powder with a density of 3,025 kg/m³, melting point T_m = 2570° ± 30° C, and boiling point T_b = 4260° ± 160° C. Under natural conditions it is very rarely encountered in the form of the mineral bromellite. Beryllium oxide is practically insoluble in water; it dissolves in acids with the formation of Be²⁺ salts. (Calcined beryllium oxide dissolves only in concentrated H₂S0₄ and HF; melted BeO, only in HF.) With alkalis it forms water-soluble beryllate salts. BeO does not react with hydrogen and is stable to the action of the majority of metals. At temperatures near 2000° C, BeO is reduced by coal in the presence of copper with the formation of copper-beryllium alloys (2–4 percent Be), which are used in the production of beryllium bronze. BeO is obtained by the thermal decomposition of beryllium hydroxide or salts. It is used as a refractory inert material for the production of crucibles and special ceramics with low electrical conductivity and high thermal conductivity (somewhat less than that of copper). In nuclear reactors it is used as a moderator and neutron reflector, as well as for the production of fuel grit (nuclear fuel with a base of UO₂ particles coated with BeO). In X-ray technology, BeO is used to make glass that passes X rays, and in organic synthesis it is used as a catalyst.