ベリリウム 化学特性,用途語,生産方法
外観
銀白色～灰黒色, 粉末
溶解性
水に不溶 (徐々に反応し水素ガスを発生する。)。希塩酸に溶ける。
主な性質
- 単体ベリリウムはもろくて硬い灰色金属である
- ベリリウムは大気中では金属表面に酸化皮膜が出来て安定するが、加熱すると金属微粉末は光を放って燃える
- 原子番号が小さく、電子が原子核に強く引き寄せられて安定である為、Ｘ線を良く通す性質がある
- ベリリウムは軽水、流水、高純度の炭素と共に中性子減速材として利用
- 用途の殆んどがベリリム銅合金（高強度バネ材など、高伝導を必要とする分野で利用）
解説
ベリリウム,Be．原子番号4の元素．電子配置1S22S2の周期表2族元素．原子量9.01．安定同位体は 9Be．ほかに3種の放射性同位体がある．1798年L.N. Vauquelinにより緑柱石中に見いだされ，1828年F. Wöhler(ウェーラー)が塩化ベリリウムをカリウムで還元して，はじめて金属を遊離した．Vauquelinと相前後してM.H. KlaprothやH. Davy(デイビー)らもエメラルド，緑柱石を分析しており，Klaprothは緑柱石berylからベリリウムを，DavyはVauquelinが提案した酸化物名glucinaをもとにグルシニウムを提案したが，1949年に至ってIUPACがベリリウムを選択した．天然には，緑柱石(ベリル)3BeO･Al2O3･6SiO2として産出する．地殻中の存在度1.5 ppm．フッ化物のマグネシウムによる還元，または塩化ベリリウムの融解電解で得られる．銀白色の六方晶系の金属．六方最密格子構造．融点1280 ℃，沸点2970 ℃．密度1.85 g cm－3(20 ℃)．常温でもろく高温で展性，延性がある．空気中では表面だけが酸化される．高温では酸素，窒素，炭素，硫黄，リン，ホウ素，ケイ素，セレン，テルル，ヒ素，ハロゲンと直接化合するが水素とは反応しない．水とは表面に酸化物皮膜をつくるだけで反応は進まない．塩酸，硫酸には水素を発生してベリリウム塩をつくり溶けるが，硝酸には侵されにくい．アルカリには水素を発生して溶け，水酸化物を生じる．ベリリウムとその化合物は有毒である．中性子の減速材，X線管の窓用や軽合金の成分などに用いられる．銅との合金はベリリウム銅として高強度ばね材料に用いられる．また，ベリリウムの合金は軽くて強いので，ミサイル，宇宙船，航空機などの構造材，ジャイロスコープ，コンピューター部品などに用いられる．
用途
銅に混ぜてベリリウム銅合金として利用される。銅よりもはるかに強く、銅と同じように電気伝導性がある。また、アルミベリリウム合金も軽量かつ強度が高い特徴があり、F-1の部品(安全性の観点から2004年以降は使用禁止)や航空機の部品にも使用されている。また、ベリリウムはX線に対する透過率が非常に高いため、X線源やビームライン、検出器などと外界を隔てる窓として用いられる。ベリリウム中を音が伝わる速度は8~13KM/Sとかなり早いので高音域スピーカーのコーンの一部に使用される例がある。
用途
合金材料、新素材研究用。
主な用途
- 金属ベリリウム（Ｘ線管、原子炉用構造体、スピーカー振動板）
- 高強度、高導電銅系展伸材（電子機器用バネ材、コネクター、スイッチ、リレー）
- 高強度、高伝導電性鋳鍛材（安全工具、プラスチック金型、溶接用電極、機械部品）
使用上の注意
純度は金属ベースで差数法によって算出したもので、重量又は容量分析等の化学的方法によるものではありません。使用目的により、正確な含量が必要な場合は、それらの方法によって測定する必要があります。
性質
銀白色のかなり軽い金属で、きわめて硬くもろい。空気中では常温で表面に酸化物の薄膜ができるため灰白色を呈するが、これが内部を保護するため、酸化はそれ以上進まず、よく磨いた面は長く光沢を失わない。高温では速やかに酸化され、粉末状であれば燃えて酸化物BeOを生ずる。酸化被膜の保護作用のため、水とは100℃でも反応しない。希塩酸や希硫酸には水素を発生して溶けるが、硝酸には不動態化して溶けない。アルミニウムと同様に水酸化アルカリに溶け、いわゆるベリリウム酸イオンを生ずる。
説明
Beryllium is widely distributed in the earth's crust at trace concentration, 2.8 mg/kg. The element was first discovered by Vauquelin in 1797. Wohler and Bussy in 1828 independently isolated beryllium in the metallic form from its oxide. In nature, beryllium occurs in several minerals, mostly combined with silica and alumina. The most common minerals are beryl, 3BeO•Al2O3•6SiO2; chrysoberyl, BeO•Al2O3; phenacite, 2BeO•SiO2; and bertrandite, 4BeO•2SiO2•H2O. Also, it is found in trace amounts in the ore feldspar, and in volcanic ash. It's abundance in the sea water is estimated in the range 5.6 ppt.
Beryllium oxide is a component of precious stones, emerald, aquamarine and topaz. Beryllium is utilized in nuclear reactors to moderate the velocity of slow neutrons. It is hot-pressed to appropriate shapes and sizes that yield high strength and ductility for its applications.
化学的特性
Beryllium is a gray shiny metal or powder, or
fine granules which resemble powdered aluminum.
Beryllium is slightly soluble in water. All beryllium compounds
are soluble in water, to some degree. Berylore is the
primary source of beryllium, although there are numerous
other sources.
用途
銅、ニッケル、鉄などとの合金の材料としての用途が主要なものである。またX線管の窓、原子炉における中性子減速材などに用いられる。金属ベリリウムとその化合物は有毒で、皮膚や肺を侵すので取扱いには注意を要する。
物理的性質
As the first element in group 2 (IIA), beryllium has the smallest, lightest, and most stableatoms of the alkali earth metals. Its melting point is 1278° C, its boiling point is 2970°C, andits density is 1.8477 g/cm
3. Its color is whitish-gray.
名前の由来
Beryllium was originally known as “glucina” (glucose) from the Greek
word glukos, meaning “sugar,” because of the sweet taste of a few of its salt compounds. Later, beryllium was given the Greek name beryllos after the greenish-blue gemstone beryl (emeralds) that was later found to contain the element beryllium.
天然物の起源
Since its discovery, beryllium has been classed as the 36th most abundant of the elementsfound in the Earth’s crust. Beryllium’s principle source is a mineral composed of a complex ofberyllium, silicon, and oxygen. It is usually found in deposits as hexagonal crystalline formsin Brazil, Argentina, South Africa, and India as well as in Colorado, Maine, New Hampshire,and South Dakota in the United States. Some deposits have been found in Canada. Manycrystals of the mineral may be very large One chunk that measured 27 feet long length andweighed a 25 tons was found in Albany, Maine in 1969.One method of obtaining beryllium metal is by chemical reduction, whereby berylliumoxide is treated with ammonium fluoride and some other heavy metals to remove impuritieswhile yielding beryllium fluoride. This beryllium fluoride is then reduced at high temperaturesusing magnesium as a catalyst, which results in deposits of “pebbles” of metallic beryllium.Another method for obtaining beryllium metal is by electrolysis of a solution of berylliumchloride (BeCl
2) along with NaCl as an electrolyte in solution that is kept molten but belowthe melting point of beryllium. (
4Be has a relatively high melting point of 2,332.4°F.) Theberyllium metal does not collect at the negative cathode as do metals in other electrolyticcells, but rather beryllium metal pieces are found at the bottom of the cell at the end of theprocess.
特性
Beryllium is one-third as dense as aluminum. Fresh-cut surfaces of the metal oxidize,thus resisting further oxidation, as does aluminum. It is a lightweight, hard, brittle metal. Itcan be machined (rolled, stretched, and pounded) into many shapes and is used to producelightweight alloys.
使用
Source of neutrons when bombarded with alpha particles according to the equation 94Be + 42He 612C + 10n. This yields about 30 neutrons per million alpha particles. Also as neutron reflector and neutron moderator in nuclear reactors. In beryllium copper and beryllium aluminum alloys (by direct reduction of beryllium oxide with carbon in the presence of Cu or Al). In aerospace, aircraft and satellite structures; x-ray transmission windows; missile parts; nuclear weapons; fuel containers; precision instruments; rocket propellants; navigational systems; heat shields; and mirrors. For fiber optics and cellular network communications systems.
調製方法
Metallic beryllium is produced by reduction of beryllium halide with sodium, potassium or magnesium. Commercially, it is obtained primarily from its ore, beryl. Beryllium oxide is separated from silica and alumina in ore by melting the ore, quenching the solid solution, and solubilizing in sulfuric acid at high temperatures and pressure. Silica and alumina are removed by pH adjustment. Beryllium is converted to its hydroxide. Alternatively, beryl is roasted with complex fluoride. The products are dissolved in water and then pH is adjusted to produce beryllium hydroxide.
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 BERYLLIUM 97 to form pure beryllium metal:
BeF +Mg→Be + MgF2
It finally is purified by either vacuum melting or chelation with an organophosphate reagent followed by liquid-liquid extraction. Beryllium halide alternatively may be reduced to the metal or converted to alloy by electrolysis.
定義
beryllium: Symbol Be. A grey metallicelement of group 2 (formerly IIA)of the periodic table; a.n. 4; r.a.m.9.012; r.d. 1.85; m.p. 1278°C; b.p.2970°C. Beryllium occurs as beryl(3BeO.Al
2O
3.6SiO
2) and chrysoberyl(BeO.Al
2O
3). The metal is extractedfrom a fused mixture of BeF
2/NaF byelectrolysis or by magnesium reductionof BeF
2. It is used to manufactureBe–Cu alloys, which are used innuclear reactors as reflectors andmoderators because of their low absorptioncross section. Berylliumoxide is used in ceramics and in nuclearreactors. Beryllium and its compoundsare toxic and can causeserious lung diseases and dermatitis.The metal is resistant to oxidation byair because of the formation of anoxide layer, but will react with dilutehydrochloric and sulphuric acids.Beryllium compounds show high covalentcharacter. The element wasisolated independently by F. W?hlerand A. A. Bussy in 1828.
反応性
Most chemical reactions of beryllium are similar to those of aluminum and, to a lesser extent, magnesium. In general, all the common mineral acids attack beryllium forming their corresponding salts with evolution of hydrogen:
Be + 2HCl → BeCl2 + H2
Cold, concentrated nitric acid, however, has no effect when mixed with the metal.
Reactions with alkalies first produce insoluble beryllium hydroxide with evolution of hydrogen. Excess alkali converts the hydroxide to water-soluble beryllate:
Be(OH)2 + 2NaOH → Na2BeO2 + H2O
Beryllium does not react with oxygen at ordinary temperatures and normal atmosphere. When heated above 700°C, the metal combines with nitrogen, (in an oxygen-free atmosphere) forming beryllium nitride, Be3N2.
Beryllium combines with carbon when heated above 900°C in the absence of air to form beryllium carbide.
2Be + 2C→（>900℃）→Be2C
Beryllium reacts incandescently with fluorine or chlorine, producing beryllium fluoride or chloride.
製法
緑柱石を融解後、酸とアルカリで処理して水酸化ベリリウムを得、焼いて酸化物に変える。これをフッ素化してフッ化ベリリウムBeF2として、約1000℃でマグネシウム還元する。また、酸化物を塩素化して塩化ベリリウムBeCl2とし、塩化ナトリウムを加えて融解電解する。1300～1400℃で減圧蒸留して精製する。
一般的な説明
A grayish-white hard light metal. Denser than water, but the powder may float. May be toxic by inhalation. Will burn if involved in a fire.
空気と水の反応
Highly flammable. Insoluble in water.
反応プロフィール
Boron trifluoride reacts with incandescence when heated with alkali metals or alkaline earth metals except magnesium [Merck 11th ed. 1989]. Finely divided or amalgamated metal reacts with HCl, dil HNO3, or dil H2SO4; attacked by strong base with evolution of hydrogen gas [Merck 11th ed. 1989]. BERYLLIUM has been determined experimentally that a mixture of BERYLLIUM with carbon tetrachloride or with trichloroethylene will flash or spark on heavy impact [ASESB Pot. Incid. 39 1968]. The reaction between beryllium and the vapors of phosphorus proceeds with incandescence [Mellor 8:842 1946-47].
危険性
The elemental metallic form of beryllium is highly toxic, as are most of its compounds.When inhaled, the fumes, dust, or particles of beryllium are highly carcinogenic. Some berylliumcompounds are toxic when they penetrate cuts in the skin (e.g., when an old fluorescenttube breaks). Beryllium oxide when inhaled can result in a fatal disease known as berylliosis(similar to, but more toxic than, silicosis).
As with many other chemicals, beryllium has its positives and negatives. Although it is animportant industrial chemical, the handling of beryllium is best left to experienced workersand laboratory personnel in proper facilities.
工業用途
Among structural metals, beryllium (symbolBe) has a unique combination of properties. Ithas low density (two thirds that of aluminum),high modulus per weight (five times that ofultrastrength steels), high specific heat, highstrength per density, excellent dimensionalstability, and transparency to x-rays. Berylliumis expensive, however, and its impactstrength is low compared to values for mostother metals.
Beryllium is a steel-gray lightweight metal,used mainly for its excellent physical propertiesrather than its mechanical properties. Except formagnesium (Mg), it is the lightest in weight ofcommon metals, with a density of 1855 kg/m3.It also has the highest specific heat (1833J/kg K) and a melting point of 1290°C. It isnonmagnetic, has about 40% the electrical conductivityof copper, a thermal conductivity of190 W/m K, high permeability to x-rays, andthe lowest neutron cross section of any metalhaving a melting point above 500°C.
職業ばく露
Beryllium is used extensively in
manufacturing electrical components, chemicals, ceramics,
nuclear reactors; in the aerospace industry; and X-ray tubes.
Beryllium and Compounds 423
A number of alloys are produced in which beryllium is
added to yield greater tensile strength, electrical conductivity,
and resistance to corrosion and fatigue. The metal is
used as a neutron reflector in high-flux test reactors. Human
exposure occurs mainly through inhalation of beryllium dust
or fumes by beryllium ore miners, beryllium alloy makers
and fabricators; phosphor manufacturers; ceramic workers;
missile technicians; nuclear reactor workers; electric and
electronic equipment workers; and jewelers. The major
source of beryllium exposure of the general population is
thought to be the burning of coal. Approximately 250,000
pounds of beryllium is released from coal and oil-fired burners.
EPA estimates the total release of beryllium to the
atmosphere from point sources is approximately 5500
pounds per year. The principal emissions are from beryllium
copper alloy production. Approximately 721,000 persons
living within 12.5 mi (20 km) of point sources are
exposed to small amounts of beryllium (median concentration
0.005 μ/m3). Levels of beryllium have been reported in
drinking water supplies and in small amounts in food.
発がん性
Beryllium and beryllium compounds are known to be human carcinogens based on sufficient evidence of carcinogenicity from studies in humans. Beryllium and beryllium compounds were first listed in the Second Annual Report on Carcinogens as reasonably anticipated to be human carcinogens based on sufficient evidence of carcinogenicity from studies in experimental animals. The listing was revised to known to be human carcinogens in the Tenth Report on Carcinogens in 2002.
環境運命予測
Beryllium compromises the immune system. Enzymes catalyzed by magnesium or calcium can be inhibited by beryllium; succinic dehydrogenase is activated. Beryllium exposure leads to a deficiency in lung carbon monoxide diffusing capacity. Hypercalcemia (excess of calcium in the blood) can occur.
Because of the toxicity of beryllium vapor and dust, all operations should be carried out in properly ventilated rooms, and with vented equipment. Source exhaust has been found to be most effective. In the presence of poorly controlled high workplace concentrations, finedust masks with filters of the specific safety level must be worn.
輸送方法
UN1567: Beryllium powder, Hazard class: 6.1;
Labels: 6.1—Poisonous material, 4.1—Flammable solid.
Structure and conformation
The space lattice of Beryllium belongs to the hexagonal system, and its close-packed hexagonal lattice has constants of a = 0.228 nm, c = 0.3977 nm (188 ℃).
不和合性
Beryllium metal reacts with strong acids;
alkalis (forming combustible hydrogen gas), oxidizable
materials. Forms shock sensitive mixtures with some
chlorinated solvents, such as carbon tetrachloride and
trichloroethylene. Incompatible with caustics, chlorinated
hydrocarbons, oxidizers, molten lithium.
廃棄物の処理
For beryllium (powder),
waste should be converted into chemically inert oxides
using incineration and particulate collection techniques.
These oxides should be returned to suppliers if possible.
Recovery and recycling is an alternative to disposal for beryllium
scrap and pickle liquors containing beryllium.
ベリリウム 上流と下流の製品情報
原材料
準備製品