Beryllium, aluminium

AH = —611 ingas—moLand (BeO) - cycles Na3AlF ) [A10] + [AlOJ a-, rfiombohedral, pass., corundum . 

Steels Cr—Mo—Al. A1 increases resist, to corrosion, wear and abrasion. 

Be(OH)2, cr, poorly soL in alk., subl. 1200,isostr. AK0H)3, a- gibbsite , hydrargillite , monocL (stab.) - bayerite , hex.  

Be40(0C0CH3 )s, cr. cub. (diamond str type), m.p. 285, subl. 220, b.p. 331, readily sol. in CHCI3, poorly in bz. in centre moLtetrah. [0 604], connect. 4 tetrah. [Be0°03] CH3COO — bidentate BeC204 -3H2O, readily soL in H2O 

Be2 Si04, phenacite Be3AySi Ois, ber 4 (tranqiarent — emerald , + Cr — aquamaiin ) Be4Si207K0H)2, bertrandite BeAl[Si04 (01 ) euc]ase  

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In the case of alloys having one constituent considerably more reactive to oxygen than the others, conditions of temperature, pressure and atmosphere may be selected in which the reactive element is preferentially oxidised. Price and Thomas used this technique to develop films of the oxides of beryllium, aluminium, etc. on silver-base alloys, and thereby to confer improved tarnish resistance on these alloys. If conditions are so selected that the inward diffusion of oxygen is faster than outward diffusion of the reactive element, the oxide will be formed as small dispersed particles beneath the surface of the alloy. The phenomenon is known as internal oxidation and is of quite common occurrence, usually in association with a continuous surface layer of oxides of the major constituents of the alloy. 

Even when modifiers are not necessary for cement formation, they can lead to improved cement properties. Kingery (1950b) also examined this effect. He found that optimum bonding was achieved with cations that had small ionic radii and were amphoteric or weakly basic, such as beryllium, aluminium, magnesium and iron. By contrast, cations that were highly basic and had large ionic radii, for example calcium, thorium and barium, had a detrimental effect on bonding. 

Beryllium, Aluminium, Zinc, Rubidium, Indium, and Lead... 

Vandecasteele et al. [745] studied signal suppression in ICP-MS of beryllium, aluminium, zinc, rubidium, indium, and lead in multielement solutions, and in the presence of increasing amounts of sodium chloride (up to 9 g/1). The suppression effects were the same for all of the analyte elements under consideration, and it was therefore possible to use one particular element, 115indium, as an internal standard to correct for the suppressive matrix effect, which significantly improved experimental precision. To study the causes of matrix effect, 0.154 M solutions of ammonium chloride, sodium chloride, and caesium chloride were compared. Ammonium chloride exhibited the least suppressive effect, and caesium chloride the most. The results had implications for trace element determinations in seawater (35 g sodium chloride per litre). 

Beryllium acetate, basic see Beryllium and beryllium compounds) Beryllium-aluminium alloy see Beryllium and beryllium compounds) Beryllium carbonate see Beryllium and beryllium compounds) Beryllium chloride see Beryllium and beryllium compounds) Beryllium-copper alloy see Beryllium and beryllium compounds) Beryllium-copper-cobalt alloy see Beryllium and beryllium compounds) Beryllium fluoride see Beryllium and beryllium compounds)... 

White, ductile, moderately hard —beryllium, aluminium, gallium, indium, tin, silver, nickel. Red, copper. Yellow, gold. 

Copper, beryllium, aluminium, gallium, palladium and iron... 

Hydroxides M(OH) comprise a numerous class of compounds ranging from strongly basic hydroxides of alkaline metals and alkaline earths, to the so-called amphoteric hydroxides (of beryllium, aluminium, zinc and others) and the hydroxides of transition metals, and further to hydroxo-acids formed by non-metals or semi-metals. 

Beryllium, aluminium and some transition metals such as thorium differ from the alkali metals in forming volatile borohydrides which constitute the most volatile compounds of these elements. On pyrolysis they decompose giving hydrogen and non-volatile residues. Electron diffraction and infrared studies suggest they possess bridge structures. 

Beryllium (6 X % of lithosphere) has its only commercial source in beryl, BegAlgSigOig. This when fused and quenched in water becomes soluble in concentrated H2SO4, giving a solution containing the sulphates of beryllium, aluminium and the alkali metals. The addition of (NH4)2S04 allows the aluminium to be removed as the sparingly soluble ammonium alum. The BeS04 is then crystallised from the solution and converted to BeO (Fig. 135). 

Emerald (Cr3+ Be3Al2(Si03)6, chromium-doped beryllium aluminium silicate or beryl) is a well known gem, and its beautiful green color has been attracted people for a long time. Nowadays, emerald crystal is also known as a tunable solid-state laser material, and its optical properties have been smdied (1-10). 

Emerald is an oxide in which chromium ions are dilutely doped and work as color active centers. The host crystal is beryllium aluminium silicate, or simply... 

The window material used in vacuum cryostats is usually beryllium, aluminium, or aluminised mylar. It should be noted, however, that commercial beryllium and aluminium often contain sufficient iron to give a detectable Fe (14 keV) resonance, and this has been known to cause problems when working with this isotope. 

The chief source of beryllium oxide is the mineral beryl, or beryllium aluminium silicate, 3Be0.Al203.6Si02, which occurs in Argentina, Brazil and India. When pure, beryllium oxide has a specific gravity of 3.0, and is almost insoluble in water it is soluble in sulphuric acid and in fused alkalis. It has been used as a refractory (melting point over 2500°C) but its toxicity has restricted its use. 

The beryllium-aluminium alloys offer another path that has to be tried out. Practically nothing is known of the behavior of these alloys in contact with uranium. 

The United States Brush Beryllium Corporation operate the Kaufmann and Kjellgren process for the sulphuric acid breakdown of beryl. Beryl is the principal beryllium mineral and consists of a beryllium aluminium silicate, 3Be0.Al20s.6SiO2. It is mined in Argentina, Brazil, South Africa, Southern Rhodesia, India and parts of the U.S.A. When pure it has a beryllium oxide content of about 14 per cent. The commercial mineral is usually fairly pure, with 10 to 12 per cent BeO, equivalent to about 4 per cent beryllium. 

Beryllium chloride is usually produced by the chlorination of the pure oxide mixed with carbon, the oxide having been obtained via a sulphuric acid or silico-fluoride breakdown of beryl. However, the direct chlorination of beryl has been considered by Sheer and Korman. It is carried out by mixing the ground mineral with about 30 per cent of soft coal and fabricating into electrodes. These are continuously consumed in an electric arc furnace through which chlorine is passed. The chlorides of beryllium, aluminium, silicon and iron, etc., are collected separately, as far as possible, by selective condensation. 

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