Solutions beryllium

Ceramic-grade beryllium oxide has also been manufactured by a process wherein organic chelating agents (qv) were added to the filtered beryllium sulfate solution. Beryllium hydroxide is then precipitated using ammonium hydroxide, filtered, and carefully calcined to obtain a high purity beryllium oxide powder. 

The precipitation by ammonia solution of such elements as Al, Bi, Cd, Cr, Ca, Cu, Fe, Pb, Mn, Ni, and Zn may be prevented by complexation with EDTA upon boiling the ammoniacal solution, beryllium hydroxide is precipitated quantitatively. 

The procedure utilises eriochrome blue black RC (also called pontachrome blue black R Colour Index No. 15705) at a pH of 4,8 in a buffer solution. Beryllium gives no fluorescence and does not interfere iron, chromium, copper, nickel, and cobalt mask the fluorescence fluoride must be removed if present. The method may be adapted for the determination of aluminium in steel. 

Pa (0.02—0.05 mm Hg) beryllium chloride sublimes at 350—380°C. It is easily hydrolyzed by water vapor or in aqueous solutions. Beryllium chloride hydrate [14871-75-1] has been obtained by concentrating a saturated aqueous solution of the chloride in a stream of hydrogen chloride. Chloroberyllate compounds have not been isolated from aqueous solutions, but they have been isolated from anhydrous fused salt mixtures. 

Iron interferes with the test and should be absent. Chromium forms a similar lake in acetate solution, but this is rapidly decomposed by the addition of the ammoniacal ammonium carbonate solution. Beryllium gives a lake similar to that formed by aluminium. Phosphates, when present in considerable quantity, prevent the formation of the lake. It is then best to precipitate the aluminium phosphate by the addition of ammonia solution the resultant precipitate is redissolved in dilute acid, and the test applied in the usual way. 

Another method for separating beryllium and aluminium consists of adding excess of a solution of sodium fluoride to the solution. The complex hexafluoro-aluminate, [A1F6]3 , is formed from which the metal is not precipitated as hydroxide by ammonia solution. Beryllium is, however, readily precipitated as the hydroxide under these conditions. 

Decrystallization of cellulose by swelling agents or solvents can be brought about by concentrated sodium hydroxide amines me-tallo-organic complexes of copper, cadmium, and iron quaternary ammonium bases concentrated mineral acids (sulfuric, hydrochloric, phosphoric) concentrated salt solutions (beryllium, calcium, lithium, zinc) and a number of recently investigated mixed solvents (J6). 

Pour the acidified solution into a beaker with approx. 50 ml of cold 4 m sodium hydroxide solution. Beryllium and aluminium remain in solution as beryllate and aluminate respectively, while iron, titanium and manganese are precipitated. Leave to stand for several hours, filter, collect the... 

Soluble beryllium salts have such great tendency to form a blue water-insoluble compound with quinalizarin (compare page 125) that solutions of even complex alkali beryllium fluoride react with ammoniacal quinalizarin solutions. Beryllium in oxygen and silicate compounds, or bound inter-metallically in alloys, may be readily converted into alkali beryllium fluoride by fusion or sintering with alkali bifluoride. The conversion involves the hydrofluoric acid derived from the thermal decomposition of the bifiuoride ... 

Whether anhydrous or in solution (beryllium or magnesium sulphate), these sulphates have no action on aluminium. Calcium and barium sulphate are insoluble. It is well known that plaster, which mainly contains calcinated calcium sulphate (gypsum) does not attack aluminium (see Section G.4.2). 

These are halides formed by highly electropositive elements (for example those of Groups I and II, except for beryllium and lithium). They have ionic lattices, are non-volatile solids, and conduct when molten they are usually soluble in polar solvents in which they produce conducting solutions, indicating the presence of ions. 

Reduction of Beryllium Fluoride with Magnesium. The Schwen2feier process (11) is used to prepare a purified, anhydrous beryUium fluoride [7787-49-7], Bep2, for reduction to the metal. BeryUium hydroxide is dissolved in ammonium bifluoride solution to give a concentration of 20 g/L... 

Beryllium Carbonates. BeryUium carbonate tetrahydrate [60883-64-9] BeCO 4H2O, has been prepared by passing carbon dioxide through an aqueous suspension of beryUium hydroxide. It is unstable and is obtained only when the solution is under carbon dioxide pressure. BeryUium oxide carbonate [66104-25-4] is precipitated when sodium carbonate is added to a beryUium salt solution. Carbon dioxide is evolved. The precipitate appears to be a mixture of beryUium hydroxide and the normal carbonate, BeCO, and usuaUy contains two to five molecules of Be(OH)2 for each BeCO. ... 

Beryllium fluoride is hygroscopic and highly soluble in water, although its dissolution rate is slow. FluoroberyUates can be readily prepared by crystallization or precipitation from aqueous solution. Compounds containing the BeP ion are the most readily obtained, though compounds containing other fluoroberyUate ions can also be obtained, eg, NH BeF, depending upon conditions. 

Beryllium Nitrate. BeryUium nitrate tetrahydrate [13516-48-0], Be(N02)2 4H2O, is prepared by crystallization from a solution of beryUium hydroxide or beryllium oxide carbonate in a slight excess of dilute nitric acid. After dissolution is complete, the solution is poured into plastic bags and cooled to room temperature. The crystallization is started by seeding. Crystallization from more concentrated acids yields crystals with less water of hydration. On heating above 100°C, beryllium nitrate decomposes with simultaneous loss of water and oxides of nitrogen. Decomposition is complete above 250°C. 

Beryllium Oxalate. BeryUium oxalate trihydrate [15771 -43-4], BeC204 -3H20, is obtained by evaporating a solution of beryUium hydroxide or oxide carbonate in a slight excess of oxaHc acid. The compound is very soluble in water. Beryllium oxalate is important for the preparation of ultrapure beryllium hydroxide by thermal decomposition above 320°C. The latter is frequentiy used as a standard for spectrographic analysis of beryUium compounds. 

Beryllium Oxide. Beryllium oxide [1304-56-9], BeO, is the most important high purity commercial beryllium chemical. In the primary industrial process, beryllium hydroxide extracted from ore is dissolved in sulfuric acid. The solution is filtered to remove insoluble oxide and sulfate impurities. The resulting clear filtrate is concentrated by evaporation and upon cooling high purity beryllium sulfate, BeSO 4H20, crystallizes. This salt is... 

Beryllium Sulfate. BeiyUium sulfate tetiahydiate [7787-56-6], BeSO TH O, is produced commeicially in a highly purified state by fiactional crystallization from a berylhum sulfate solution obtained by the reaction of berylhum hydroxide and sulfuric acid. The salt is used primarily for the production of berylhum oxide powder for ceramics. Berylhum sulfate chhydrate [14215-00-0], is obtained by heating the tetrahydrate at 92°C. Anhydrous berylhum sulfate [13510-49-1] results on heating the chbydrate in air to 400°C. Decomposition to BeO starts at about 650°C, the rate is accelerated by heating up to 1450°C. At 750°C the vapor pressure of SO over BeSO is 48.7 kPa (365 mm Hg). 

Beryllium, calcium, boron, and aluminum act in a similar manner. Malonic acid is made from monochloroacetic acid by reaction with potassium cyanide followed by hydrolysis. The acid and the intermediate cyanoacetic acid are used for the synthesis of polymethine dyes, synthetic caffeine, and for the manufacture of diethyl malonate, which is used in the synthesis of barbiturates. Most metals dissolve in aqueous potassium cyanide solutions in the presence of oxygen to form complex cyanides (see Coordination compounds). 

Chemical Reactivity - Reactivity with Water Reacts vigorously as an exothermic reaction. Forms beryllium oxide and hydrochloric acid solution Reactivity with Common Materials Corrodes most metals in the presence of moisture. Flammable and explosive hydrogen gas may collect in confined spaces Stability During Transport Stable Neutralizing Agents for Acids and Caustics Flush with water and rinse with dilute solution of sodium bicarbonate or soda ash Polymerization Not pertinent Inhibitor of Polymerization Not pertinent. 

Anhydrous beryllium halides cannot be obtained from reactions in aqueous solutions because of the formation of hydrates such as [Be(H20)4]F2 and the subsequent hydrolysis which attends attempted dehydration. Thermal decomposition of (NH4)2Bep4 is the best route for BeFr, and BeCl2 is conveniently made from the oxide... 

Beryllium dialkyls (BeR2, R = Me, Et, Pr", Pr, Bu etc.) can be made by reacting lithium alkyls or Grignard reagents with BeCl2 in ethereal solution, but the products are difficult to free from ether and, when pure compounds rather than solutions are required, a better route is by heating Be metal with the appropriate mercury dialkyl ... 

Dilute binary alloys of nickel with elements such as aluminium, beryllium and manganese which form more stable sulphides than does nickel, are more resistant to attack by sulphur than nickel itself. Pfeiffer measured the rate of attack in sulphur vapour (13 Pa) at 620°C. Values around 0- 15gm s were reported for Ni and Ni-0-5Fe, compared with about 0-07-0-1 gm s for dilute alloys with 0-05% Be, 0-5% Al or 1-5% Mn. In such alloys a parabolic rate law is obeyed the rate-determining factor is most probably the diffusion of nickel ions, which is impeded by the formation of very thin surface layers of the more stable sulphides of the solute elements. Iron additions have little effect on the resistance to attack of nickel as both metals have similar affinities for sulphur. Alloying with other elements, of which silver is an example, produced decreased resistance to sulphur attack. In the case of dilute chromium additions Mrowec reported that at low levels (<2%) rates of attack were increased, whereas at a level of 4% a reduction in the parabolic rate constant was observed. The increased rates were attributed to Wagner doping effects, while the reduction was believed to result from the... 

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