Beryllium metal

Group IIB and know that this means the group of elements zine. cadmium and mercury, whilst Group IIA refers to the alkaline earth metals beryllium, magnesium, calcium, barium and strontium. 

The alkali metals of Group I are found chiefly as the chlorides (in the earth s crust and in sea water), and also as sulphates and carbonates. Lithium occurs as the aluminatesilicate minerals, spodimene and lepidolite. Of the Group II metals (beryllium to barium) beryllium, the rarest, occurs as the aluminatesilicate, beryl-magnesium is found as the carbonate and (with calcium) as the double carbonate dolomite-, calcium, strontium and barium all occur as carbonates, calcium carbonate being very plentiful as limestone. 

Beryllium is found in some 30 mineral species, the most important of which are bertrandite, beryl, chrysoberyl, and phenacite. Aquamarine and emerald are precious forms of beryl. Beryl and bertrandite are the most important commercial sources of the element and its compounds. Most of the metal is now prepared by reducing beryllium fluoride with magnesium metal. Beryllium metal did not become readily available to industry until 1957. 

Magnesium fluoride is a by-product of the manufacture of metallic beryllium and uranium. The beryllium or uranium fluorides are intimately mixed with magnesium metal in magnesium fluoride-lined cmcibles. On heating, a Thermite-type reaction takes place to yield the desired metal and Mgp2 (13). Part of the magnesium fluoride produced in this reaction is then used as a lining for the cmcibles used in the process. 

The salts of the heavy metals beryllium, cadmium, chromium, copper, lead, mercury, nickel and zinc are all of high eco-toxicity. For example, the toxicity of some heavy metals to rainbow trout is demonstrated in Table 16.13 coarse fish are somewhat more resistant. 

Water as an impurity is known to promote the breakaway corrosion of a number of metals in addition to iron in CO2 the effect has been reported for magnesium (hydrocarbons have more effect on the oxidation of this metal), beryllium, zirconium and sodium. In the latter case water is known to convert the oxide to deliquescent NaOH but acceleration of beryllium oxidation probably results from hydride formation and mechanical damage to the oxide. 

As a light, strong metal, beryllium holds considerable promise as a useful engineering material, but because of an inherent directional brittleness, a really significant commercial use, e.g. in the aircraft industry, has not proved possible. It has been used to a limited extent in aerospace applications, and it was employed as heat shields for the Project Mercury space capsule. It has also found use in precision guidance systems when fairly pure environmental conditions can be assured. 

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. 

Table 21-IV shows some properties of the metals and their crystal forms. Since different crystal forms are involved in the series, trends in the properties are obscured. Figure 21-2 shows scale representations of the crystal structures of metallic beryllium, calcium, and barium.

Chlorine has caused numerous accidents with metals. Beryllium becomes incandescent if it is heated in the presence of chlorine. Sodium, aluminium, aluminium/titanium alloy, magnesium (especially if water traces are present) combust in contact with chlorine, if they are in the form of powder. There was an explosion reported with molten aluminium and liquid chlorine. The same is true for boron (when it is heated to 400°C), active carbon and silicon. With white phosphorus there is a detonation even at -34°C (liquid chlorine). 

Conroy and Perlow [235] have measured the Debye-Waller factor for W in the sodium tungsten bronze Nao.gWOs. They derived a value of/= 0.18 0.01 which corresponds to a zero-point vibrational amplitude of R = 0.044 A. This amplitude is small as compared to that of beryllium atoms in metallic beryllium (0.098 A) or to that of carbon atoms in diamond (0.064 A). The authors conclude that atoms substituting tungsten in bronze may well be expected to have a high recoilless fraction. 

The metal beryllium is prepared from its fluoride by magnesiothermic reduction. Calcium can not be used for this purpose because it would interact with beryllium to form a stable intermetallic phase (CaBel3). 

Iversen, B.B., Larsen, F.K., Souhassou, M. and Takata, M. (1995) Experimental evidence forthe existence of non-nuclear maxima in the electron density distribution of metallic beryllium. A comparative study ofthe maximum entropy method and the multipole method, Acta Cryst., B51, 580-591. 

We originally proposed NNM to be present in metallic beryllium [30] based on analysis of the X-ray diffraction data measured by Larsen and Hansen [24], Based on Fourier maps and elaborate multipole least-squares modeling, indisputable evidence... 

Figure 3. Contour plots of the bias corrected MEM densities in the (110) plane of metallic beryllium (a) uniform prior, (b) non-uniform prior. The plots are on a linear scale with 0.05 el A1 intervals. Truncation at 1.0e/A3. Maximum values in e/A3 are given at the Be position and in the bipyramidal space of the hep structure.

Heavy Metals, Beryllium, Bismuth, Gallium, Mercury, and Indium... 

One method of obtaining beryUium metal is by chemical reduction, whereby beryllium oxide is treated with ammonium fluoride and some other heavy metals to remove impurities while yielding berylhum fluoride. This beryllium fluoride is then reduced at high temperatures using magnesium as a catalyst, which results in deposits of pebbles of metallic beryllium. 

Beryllium metal, beryllium-aluminum alloy, beryl ore, beryllium chloride, beryllium fluoride, beryllium hydroxide, beryllium sulfate, and beryllium oxide all produce lung tumors in rats exposed by inhalation or intra-tracheally. The oxide and the sulfate produce lung tumors in monkeys after intrabronchial implantation or inhalation. A number of compounds produce osteosarcomas in rabbits after their intravenous or intramedullary administration. ... 

Metallic beryllium is produced by reduction of beryllium halide with sodium, potassium or magnesium. Commercially, it is obtained primarily from its ore, beryl. Beryllium oxide is separated from silica and alumina in ore by melting the ore, quenching the solid solution, and solubilizing in sulfuric acid at high temperatures and pressure. Silica and alumina are removed by pH adjustment. Beryllium is converted to its hydroxide. Alternatively, beryl is roasted with complex fluoride. The products are dissolved in water and then pH is adjusted to produce beryllium hydroxide. 

Metallic beryllium was first prepared m August, 1828, by F. Wohler and A.-A.-B. Bussy independently by the action of potassium on beryllium chloride (7, 8). Wohler placed alternate layers of the chloride and flattened pieces of potassium in a platinum crucible, wired the cover on strongly, and heated the mixture with an alcohol lamp. The reaction began immediately and took place with such intensity that the crucible became white-hot. After cooling it thoroughly, he opened it and placed... 

The band of molecular orbitals formed by the 2s orbitals of the lithium atoms, described above, is half filled by the available electrons. Metallic beryllium, with twice the number of electrons, might be expected to have a full 2s band . If that were so the material would not exist, since the anti-bonding half of the band would be fully occupied. Metallic beryllium exists because the band of MOs produced from the 2p atomic orbitals overlaps (in terms of energy) the 2s band. This makes possible the partial filling of both the 2s and the 2p bands, giving metallic beryllium a greater cohesiveness and a higher electrical conductivity than lithium. 

The participation of the 2p band in the bonding of metallic beryllium explains the greater cohesiveness (bond strength) of the metal when compared to that of lithium, and also why the enthalpies of atomization and the melting temperatures of the two metals are different, as shown by the data in Table 7.2. 

It would be interesting to extend such studies to other light-atom substrates, such as the metals beryllium and aluminium, and to investigate step effects. Heavier-atom surfaces can also be analyzed in the form of thin films of mono-atomic thickness on a lighter substrate, as has recently been done ... 

Reduction of Beryllium Fluoride with Magnesium. The Schwenzfeier process (11) is used to prepare a purified, anhydrous beryllium fluoride [7787-49-7], BeF2, for reduction to the metal. Beryllium hydroxide is dissolved in ammonium bifluoride solution to give a concentration of 20 g/L... 

D. W. White and J. E. Burke, eds., The Metal Beryllium, American Society for Metals, Novelty, Ohio, 1955. 

Beryllium bromide [7787-46 4], BeBi, and beryllium iodide [7787-53-3], Bel2, are prepared by the reaction of bromine or iodine vapors, respectively, with metallic beryllium at 500—700°C. They cannot be prepared by wet methods. Neither compound is of commercial importance and special uses are unknown. 

The problem of the stability of the complexes of the transition metals was for many years a puzzling one. Why is the cyanide group so facile in the formation of complexes with these elements, whereas the carbon atom in other groups, such as the methyl group, does not form bonds with them Why do the transition metals and not other metals (beryllium, aluminum, etc.) form cyanide complexes In the ferro-... 

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