Beryllium hydroxide salts

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... 

Dissolve about 10 g. of commercial beryllium hydroxide or carbonate in acetic acid and evaporate to dryness on the hot plate. Dissolve the dry residue in boiling glacial acetic acid and set aside for crystallization. The salt is deposited in small colorless octahedra. These should be drained on a Witte plate and dried on paper. The salt is decomposed by wat er. 

Beryllium Carbonates. Beryllium carbonate tetrahydrate [60883-64-9], BeC03 4H20, has been prepared by passing carbon dioxide through an aqueous suspension of beryllium hydroxide. It is unstable and is obtained only when the solution is under carbon dioxide pressure. Beryllium oxide carbonate [66104-25-4] is precipitated when sodium carbonate is added to a beryllium salt solution. Carbon dioxide is evolved. The precipitate appears to be a mixture of beryllium hydroxide and the normal carbonate, BeC03, and usually contains two to five molecules of Be(OH)2 for each BeC03. 

Beryllium Sulfate. Beryllium sulfate tetrahydrate [7787-56-6], BeS04 4H20, is produced commercially in a highly purified state by fractional crystallization from a beryllium sulfate solution obtained by the reaction of beryllium hydroxide and sulfuric acid. The salt is used primarily for the production of beryllium oxide powder for ceramics. Beryllium sulfate dihydrate [14215-00-0], is obtained by heating the tetrahydrate at 92°C. Anhydrous beryllium sulfate [13510-49-1] results on heating the dihydrate 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 S03 over BeS04 is 48.7 kPa (365 mm Hg). 

Beryllium Metavanadate, Be(V03)2.4H20.—Addition of solutions of beryllium salts to alkali vanadates gives rise to basic vanadates of indefinite composition. The pure salt is obtained by boiling beryllium hydroxide and vanadium pentoxide in water in the required proportions. The solution is filtered, concentrated to a syrup and poured into alcohol, whereupon isometric cubes, modified by an octahedron, are obtained. The larger crystals polarise light. Density, 2-273. One gram dissolves in a litre of water at 25° C.s... 

Beryllium hydroxide, [CAS 13327-32-7], Be(OH)2 is precipitated as an amorphous, gelatinous material by addition of ammonia or alkali to a solution of a beryllium salt at slightly basic pH values. A pure hydroxide can be prepared by pressure hydrolysis of a sluriy of beryllium basic carbonate in water at 165°C. All forms of beryllium hydroxide begin to decompose in air or water to beryllium oxide at 190c C. 

Beryllium Chromate, BeCrO4.H20, and the basic eonqrouud, EeCr04.6Ee(0TI).2, have been described by Glassmaun, whose results, however, have not been confirmed by subsequent workers. It appears to be established that a solution of chromic acid absoi bs beryllium hydroxide in the exact ratio of iBe(OH)., K rOj, w hich points to the formation of the neutral chromate. When solutions of beryllium salts are treated with equivalent quantities of chromates, the prccij titates at first formed redissolve but if the chromate is added in excess, yellow precipitates of strongly basic beryllium chromates of uncertain composition are obtained. 

PROBABLE FATE photolysis no data found on photolysis of beryllium oxidation not an important process hydrolysis soluble beryllium salts are hydrolyzed to form insoluble beryllium hydroxides volatilization airborne dusts are the most widely known hazard associated with beryllium sorption no data found on adsorption of beryllium biological processes only slightly bioaccumulated... 

The O form is the primary product of aging of amorphous beryllium hydroxide, which is obtained by the precipitation of a beryllium salt solution with ammonia in the absence of COg Be (OH) g is then obtained by prolonged heating (about 24 hours) of the amorphous precipitate with 10% ammonium hydroxide solution. 

This step eliminates a false positive reaction caused by the presence of zinc, which would stay in solution because of formation of the soluble complex [Zn(NH3)4] (see 3.35. Zinc). The step is, however, most likely redundant, since Zn + should already have been eliminated in the sulfide precipitation. But since Be + does not forma soluble ammonium complex but reprecipitates a beryllium hydroxide, it could cause a false positive. Realistically, though, one must say that the presence of a beryllium salt in a raw material for pharmaceutical production is not very likely. 

Beryllixun Sulphite, BeSOa.— The normal salt has been pro-beryllium hydroxide which had been ilriecl l>y washing with alcohol, to alcohol saturated with sulphur dioxide and evaporating over phosphoric anhydride. It con-.sists of colorless hexagonal plates which are immediately decomposed by water 5delding sulphur dioxide and beryllium hydroxide, For several so-called basic compounds see basic salts. Attcrberg- (1873 7) could not produce a sulphite. 

Potassium Beryllium Sulphite, 2BeSOs.K2SO8.9H2O.— Rosenheim and Woge (1897 4J obtained this salt in the crystalline form by saturating acid potassium sulphite with beryllium hydroxide and after filtering, passing in excess of sulphur diox-... 

Potassium Beryllium Carbonate.—By a similar procedure to the preceding. Debray obtained a double salt or a mixture to which he assigned the analogous formula, 3(BeCOj.KaCOg). Be(OH)2. It was obtained in the form of a white precipitate by adding alcohol to a solution of beryllium hydroxide in potassium carbonate. 

Precipitates beryllium hydroxide from neutral solution of pure salts by a mixture of potassium iodide and iodate after previous removal of iron and alumina. Has the advantage over NH OH that the precipitate is easily wa.shed. 

In Fig. 9.13, the heat treatments are necessary to improve the efficiency of the sulphation step. The latter can be engineered in several alternative types of plant. Alternatives are available for the subsequent steps to pure oxide, but usually based upon precipitation and crystallization, as is the one shown in Fig. 9.13. The precipitation of beryllium hydroxide by boiling an alkaline solution of sodium beryllate, is a particularly valuable purification step, and is also used in Fig. 9.14. Chlorination of oxide mixed with carbon is a standard type of operation as used for the preparation of chloride intermediates of other metals. Molten salt electrolysis is one of the two alternative commercial routes to pure beryllium metal, the other being shown in Fig. 9.14. 

The gravimetric determination of beryllium may involve the precipitation of beryllium-ammonium phosphate or beryllium hydroxide. In many methods, organic reagents are employed and in others, organic salts of beryllium. Volumetric methods for the determination of beryllium are based on the formation of stable stoichiometric complexes of beryllium. The use of complexes of beryllium eliminates the labor involved in the separation of interfering elements when beryllium is determined in multicomponent media [17]. 

Similarly, the cations that form strong bases (the alkali metals and the metals below beryllium in Group 2 (IIA)) do not tend to react with hydroxide ions. These cations are weaker acids than water. Therefore, when a salt contains one of these ions (for example, Na ) the cation has no effect on the pH of an aqueous solution. 

The impure hydroxide obtained above is purified by converting to a double salt, ammonium beryllium fluoride, which subsequently, on thermal decomposition, gives beryllium fluoride. The latter is heated with magnesium metal... 

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