Beryllium powder

It is reported that beryllium powder, of unspecified particle size, will burn in air at 1 200°C and react with nitrogen at 500 C Fluorine appears to attack beryllium at room temperature, and the other halogens, nitrogen dioxide and hydrogen sulphide are said to attack it at elevated temperatures ... 

The magnesium-reduced beryllium pebbles generally assay 96% beryllium and are always associated with residual magnesium and slag. These pebbles are purified to about 99.5% by vacuum induction melting in beryllia crucibles at temperatures of about 1400 °C. The ingots are machined and machined scarf is milled to produce beryllium powder. The ground metal powder is pressed and sintered under vacuum. The product is called vacuum hot-pressed beryllium, and this is machined for component manufacture. 

The standard reduction potential for Be2+ is the least negative of the elements in the group and by the same token beryllium is the least electropositive and has the greatest tendency to form covalent bonds. The bulk metal is relatively inert at room temperature and is not attacked by air or water at high temperatures. Beryllium powder is somewhat more reactive. The metal is passivated by cold concentrated nitric acid but dissolves in both dilute acid and alkaline solutions with the evolution of dihydrogen. The metal reacts with halogens at 600°C to form the corresponding dihalides. 

Die compaction of simple shapes can be carried out at elevated temperature using carbide, superalloy, refractory metal, or graphite dies. An inert gas atmosphere or vacuum is often used to protect the die and/or the powder. For example, beryllium powder is compacted at about 1350°C in a graphite die under vacuum with pressures of 2-4 MPa. 

Cold-isostatic-pressing followed by vacuum sintering or HIP is also used to manufacture smaller intricate shapes. In this instance beryllium powder is loaded into shaped rubber bags and pressed isostatically in a pressure chamber up to 410 MPa (60,000 psi). After the pressing operation the rubber bag is stripped from the part which is then vacuum sintered to about 99% of theoretical density at about 1200°C. If full theoretical density is required, the sintered part may be simply given a HIP cycle because there is no open porosity after vacuum sintering. In a similar manner, conventional axial cold-pressing... 

The price of beryllium oxide powder was 154/kg in 1991. The beryllium content of copper—beryllium master alloy was 352/kg. Pure beryllium powder was priced at 615/kg whereas simple shapes in vacuum hot-pressed material were priced at about 685/kg in 1991. 

SYNS BERYLLIUM-9 BERYLLIUM COMPOUNDS, n.o.s. (UN 1566) (DOT) BERYLLIUM, powder (UN 1567) (DOT) GLUCINIUM GLUCINUM RCRA WASTE NUMBER POl 5... 

Beryllium is a very toxic metal. It is especially dangerous in powder form. The effects of inhaling beryllium powder can be acute or chronic. Acute effects are those that occur very quickly as the result of large exposures. Chronic effects are those that occur over very long periods of time as the result of much smaller exposures. Acute effects of inhaling beryllium powder include pneumonia-like symptoms that can result in death in a short time. Chronic effects include diseases of the respiratory system (throat and lungs), such as bronchitis and lung cancer. 

Be otherwise capable of causing or significantly contributing to an increase in serious, irreversible, or incapacitating reversible illness. Wastes listed in this manner are classified as acute hazardous wastes that become subject to full hazardous waste regulation in smaller quantities than those for other hazardous wastes. An example of an acute listed hazardous waste is P0I5, beryllium powder. 

As FGM interlayer, eleven kinds of sintered compacts in which the mixing ratio of beryllium powder and oxygen free copper powder was different, were manufactured by powder metallurgical method, that is, HP and HIP. In this study, to estimate thermal stress at joining interface, thermal conductivity and thermal expansion coefficient of Be/Cu sintered compacts were measured by laser flash method and laser interferometry method, respectively. The characterization on these compacts was performed by using SEM (Scanning Electron Microscope) to investigate distribution of intermetallic phases on these compacts. 

Five-tenths gram of beryllium powder or chips f (0.056 mol) is placed in a pyrex boat in reaction chamber B. The open end is then sealed at A. Both reaction chamber B... 

CHEMICAL PROPERTIES stable under ordinary conditions of use and storage hazardous polymerization has not been reported reacts with chemically active metals such as sodium, potassium, beryllium, powdered magnesium, aluminum, and zinc will attack some... 

The nuclide gCf emits neutrons through spontaneous fission in 3% of all decays, the rest being a-decays. All the other neutron sources listed involve a radioactive nuclide whose decay causes a nuclear reaction in a secondary substance which produces neutrons. For example, ffSb produces neutrons in beryllium powder or metal as a result of the initial emission of 7-rays, in which case there is no coulomb barrier to penetrate. Radium, polonium, plutonium, and americium produce neutrons by nuclear reactions induced in beryllium by the a-particles from their radioactive decay. For the neutrons produced either by spontaneous fission in californium or by the a-particle reaction with beryllium, the... 

Incompatibilities and Reactivities Chemically-active metals such as potassium, beryllium, powdered aluminum, zinc, calcium, magnesium sodium acids ... 

Synonyms Beryllium, powder Classification Metallic element Empirical Be... 

Beryllium, powder. See Beryllium Beryllium sulfate tetrahydrate CAS 7787-56-6 EINECS/ELINCS 236-842-2 UN 1566... 

After complete reduction, the melt is maintained unstirred at a temperature just below 1100 C to allow the beryllium powder to collect near the surface and sinter together. It is important that the boiling-point of magnesium (1107°C) is not reached, for above this temperature the reduction reaction tends to reverse and re-form beryllium fluoride and magnesium metal. 

The neutron provided the nuclear physicist (or chemist) for the first time with a simple means to carry out artificial nuclear reactions. The production of neutrons did not require large and expensive accelerators. A mixture of beryllium powder with an a emitter in a little tube was sufficient to produce a neutron source of 10 neutrons per second. Neutrons possess no charge. Consequently, they do not have to overcome a Coulomb barrier and therefore do not have to be accelerated to enter an atomic nucleus. On the contrary, capture cross sections are usually larger for neutrons of smaller energy (thermal neutrons) because due to their lower velocity their residence time near a particular nucleus is larger. 

It can be prepared by heating a mixture of beryllium powder and nitrogen gas at high temperatures. Write the complete, balanced equation for this reaction. How many moles of beryllium are required to react completely with... 

Liquid O2F2, close to its melting point, reacts vigorously when added to charcoal cooled to 90 K. It does not appear to react with beryllium powder even upon warming to room temperature [1,2]. O2F2 reacted vigorously when added rapidly to red phosphorus at 110 K [1,2]. 

The list of industries using powders, or processes in which there is a substance used as spray or a mist, is long and increasing. My first exposure to the problems of powder technology began in 1955 when I studied the characterization of powders used to fabricate parts of nuclear weapons. One study involved the metal beryllium which was used in powder form. The production of dense beryllium required powders having a specific size and shape distribution. Beryllium powder is however a respirable health hazard and to characterize the powder in a safe atmosphere required the development of new methods of characterizing powders. 

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