Beryllium solubility data

All of the data available from literature studies for the solubility of beryllium hydroxide and oxide phases have been retained in this review. The solubility data for a-Be(OH)2(s), -Be(OH)2(s) and BeO(s) are all linear functions ofthe reciprocal of absolute temperature (Figure 7.2). The data are described by the following equations ... 

Some pertinent data for the elements are given in Table 4-1. Beryllium has unique chemical behavior with a predominantly covalent chemistry, although it forms an aqua ion [Be(H20)4]2+. Magnesium has a chemistry intermediate between that of Be and the heavier elements, but it does not stand in as close relationship with the predominantly ionic heavier members as might have been expected from the similarity of Na, K, Rb, and Cs. It has considerable tendency to covalent bond formation, consistent with the high charge/radius ratio. For instance, like beryllium, its hydroxide can be precipitated from aqueous solutions, whereas hydroxides of the other elements are all moderately soluble, and it readily forms bonds to carbon. 

The solvents most frequently mentioned as dissolving the metal acetylacetonates are benzene, ethanol, chloroform, carbon tetrachloride, carbon disulfide, and petroleum ether. Since the solubility in petroleum ether is much less than in benzene, the former is frequently added to a saturated solution in the latter to effect crystallization. Hatch and Sutherland13 give data on the solubilities of sodium, potassium, magnesium, beryllium, and aluminum acetylacetonates in benzene, cyclohexane, and n-hexane from 0 to 100°. Other solubility measurements are as follows copper(II) acetylacetonate, 0.00338 mol/1. in benzene at 25° 57 zirconium acetylacetonate, 200, 34, 47, and 56 g./l. in absolute ethanol, carbon disulfide, carbon tetrachloride, and acetylacetone, respectively, at 25°.4 Recent data by Blanch58 are assembled in the following table. 

Solubility with temperature data for nitrogen, aluminium, boron, gallium and phosphorus, on both Si and C faces, and maximum solubilities for a wider range of impurities at temperatures >2500°C in 6H-SiC have been detailed. No data for other polytypes are available. Diffusion rates of impurities in SiC are very slow (for temperatures between 1800 and 2300 °C) whether for those species, such as boron and nitrogen, which migrate via Si/C vacancies or for those, such as beryllium, lithium and hydrogen, which diffuse interstitially. Some impurities show 2-component diffusion profiles. 

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... 

Soboleva etal. (1977) also provided data on the solubility of bromellite (BeO(s)). They studied the solubility of this phase over the temperature range of 150-250 °C but provided thermodynamic data over the larger range of 25-300 C. From the solubility study, they provided data for the stability constants of the beryllium hydrolysis species, BeOH", Be(OH)2(aq) and Be(OH)3 , as well as that of the... 

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