Beryllium production

Primary beryllium production occurs at two plants within the U.S. One of these plants discharges its wastewater to the environment. Because of the limited number of facilities, beryllium production will not be discussed in this chapter. 

Beryllium, beryllium-containing alloys, and beryllium oxide ceramic in solid or massive form present no hazard whatsoever (31). Solid shapes maybe safely handled with bare hands (32) however, care must be taken in the fabrication and processing of beryllium products to avoid inhalation of airborne beryllium particulate matter such as dusts, mists, or fumes in excess of the prescribed workplace exposure limits. Inhalation of fine airborne beryllium may cause chronic beryllium disease, a serious lung disease in certain sensitive individuals. However, the vast majority of people, perhaps as many as 99%, do not react to beryllium exposure at any level (33). The biomedical and environmental aspects of beryllium have been summarized (34). 

The density of beryllium is 1.847 g/cm3 based upon average values of lattice parameters at 255C (a — 22.856 nm and c — 35.832 nm). Beryllium products generally have a density around 1.850 g/cm3 or higher because of impurities, such as aluminum and other metals, and beryllium oxide. The crystal structure is close-packed hexagonal. The alpha-form of beryllium transforms to a body-centered cubic structure at a temperature very close to the melung point. 

New astrophysical knowledge regarding beryllium could lead to answers about the beginning of the universe. The standard theory of the big bang provides for at most 1 percent beryllium production. In some very old stars, however, up to 1,000 times more beryllium than... 

Within beryllium production plants, most scrap beryllium is recycled and reused. However, beryllium-copper alloys that are recycled at metal reclaiming plants are purified for their copper and not beryllium. In these situations the beryllium is a contaminant and workers may be unknowingly exposed to beryllium (Cullen et al. 1987). 

Figure 1—A(>. Beryllium production by direct decomposition of its dichloride (BeCl2) in atmospheric-pressure thermal plasma. Composition of products (1) BeCl2 (2)BeCl (3) Cl x 0.1 (4) Be.

Bryant, P. S. Beryllium production at Milford Haven. I.M.M. Symposium on the Extraction Metallurgy of Some of the Less Common Metals, London (1956). Paper 17. 

All the derivatives obtained in the above reactions are white crystalline solids, dimeric in solution (benzene) except the beryllium derivative which also dimerizes on ageing. The beryllium product was distilled at 190°C under 0.05 mm pressure whereas under these conditions the magnesium derivative yielded a sublimate corresponding in analysis to Mg4Zr6Cl3(0I )2303. All these products appear to be chloride bridged, which is corroborated by the crystal structure of the Mg-Ti product. " ... 

Commercial production of berylHum metal began in 1957 but the market for it has not grown to the size once imagined. Today the US mainly supplies processed beryllium products. Treatment of bertrandite with hot sulfuric add gives a solution containing beryUium sulfate and other metals. Separation occurs by liquid-liquid extraction and ion exchange. After separation, beryllium carbonate is precipitated and can be transformed into different salts and to the oxide. The metal is prepared by reduction of beryUium fluoride with magnesium or by electrolysis of fused beryllium chloride. 

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. 

Inhalation of certain fine dusts may constitute a health hazard. Eor example, exposure to siUca, asbestos, and beryllium oxide dusts over a period of time results ki the potential risk of lung disease. OSHA regulations specify the allowable levels of exposure to kigestible and respkable materials. Material Safety Data Sheets, OSHA form 20, available from manufacturers, provide information about hazards, precautions, and storage pertinent to specific refractory products. 

Recycling. Beryllium is typicaUy recycled, thus it is not a waste disposal problem in fact, it is rarely a waste product at aU. Because of the high cost of producing beryUium, beryUium producers repurchase clean scrap from customers for recycling and reuse. 

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). 

Refractories for Electric Reduction Furnaces. Carbon hearth linings are used in submerged-arc, electric-reduction furnaces producing phosphoms, calcium carbide, all grades of ferrosilicon, high carbon ferrochromium, ferrovanadium, and ferromolybdenum. Carbon is also used in the production of beryllium oxide and beryllium copper where temperatures up to 2273 K ate requited. 

Nonferrous metallurgy is as varied as the ores and finished products. Almost every thermal, chemical, and physical process known to engineers is in use. The general classification scheme that follows gives an understanding of the emissions and control systems aluminum (primary and secondary), beryllium, copper (primary and secondary), lead (primary and secondary), mercury, zinc, alloys of nonferrous metals (primary and secondary), and other nonferrous metals. 

Fire Hazards - Flash Point Not pertinent. This is a combustible solid Flammable Limits in Air (%) Not pertinent Fire Extinguishing Agents Graphite, sand, or any other inert dry powder Fire Extinguishing Agents Not To Be Used Water Special Hazards of Combustion Products Combustion results in beryllium oxide fumes whieh are toxic to inhalation Behavior in Fire Powder may form explosive mixture in air Ignition Temperature (deg. F) Not pertinent Electrical Hazard Not pertinent Burning Rate Not pertinent. 

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