ビスマス 化学特性,用途語,生産方法
外観
銀灰色～褐銀白色, 粒状
溶解性
硝酸に溶ける。
解説
ビスマス,Bi．原子番号83の元素．電子配置[Xe]4f 145d106s26p3の周期表15族非金属元素．原子量208.98040(1)．もっとも高い原子番号の非放射性元素．安定核種が質量数209の同位体のみの単核種元素．質量数184～218の放射性同位体がある．千年以上前から鉛，スズの混合物の一つとみなされて使われていたが，16世紀には純金属であることがわかっていた．Paracelsus Wismuthとよんでいるが，語源は酸化物が白いところから，ドイツ語の“白い塊”，weiße Masseにちなむとされる．ドイツ語の元素名はBismut，英語・フランス語名はbismuthである．アラビア語の“融けやすい”が語源という説のほか，諸説がある．1773年，フランスのC. Geoffroyにより新元素であることが示された．宇田川榕菴は天保8年(1837年)に出版した「舎密開宗」で，亜比斯繆母(ピスシュテュム)蒼鉛としている．
主な性質
- ビスマスは光沢ある銀白色の金属で、結晶は極めて脆い
- 融点が２７１℃と低く、更に凝固時に体積変化を起こさないので低融点合金として利用
- 全金属中最も反磁性が強く、ホール効果によって最大の抵抗増加を示す特異な物性を持つ
- ビスマスは非常に大きい熱起電力を示す
- ビスマス系酸化物高温超伝導体が大きく注目
- 金属ビスマスは鋳鉄の脆性を防ぐ性質がある（鋳鉄中の亜鉛の作用を制御）
- 快削アルミニウム合金の添加成分として使われる（削りくずが細かくなる）
用途
合金材料。原子炉材、熱電対材料。
用途
半導体用、顔料
用途
工業用ビスマス塩、可融合金、ステレオタイプの金属、可溶性ボイラープラグ、電気ヒューズ、低融点はんだ、鋼の焼き戻し槽、歯科技工の鏡の銀メッキ
用途
無鉛はんだ，スプリンクラー用温度ヒューズなどに用いられる易融金属．おもな用途は，冶金添加剤，鉄鋼の機械加工性改良用添加剤，磁石・メモリー用フェライト，低融点合金用など．抗菌剤，医薬品(制酸剤など)，石油化学用触媒などにも用いられる．新しい用途には，光記録(CD-R，CD-RW)媒体，光磁気記録(MD，MO)用保護膜用材料がある．高温超伝導体(ビスマス系)の成分としても知られている．
主な用途
- 低融点合金の成分（自動消火器、ヒューズ、ハンダ）
- 金型用合金（鋳物のひな型）
- 可鍛鋳鉄部品（継ぎ手）
- 快削アルミニウム合金部品（電子部材のアルミ軸）
- バリウムフェライト（各種モーター）
- バリスタ、コンデンサー（テレビ、ラジオ）
- 触媒（化学製品製造用）
存在
輝蒼鉛鉱Bi2S3，蒼鉛華Bi2O3，ビスマタイト(BiO)2CO3などが主要鉱石である．地殻中の存在度0.06 ppm．可採埋蔵量320百万t の75％ が中国，以下ペルー，ボリビア，メキシコが各約3％．親銅元素の一つ．おもに鉛精錬の電解スライムから副産物として得られる．
性質
単体は赤味を帯びた銀白色．三方晶系．金属はもろい．密度9.747 g cm－3(20 ℃)，液体10.05 g cm－3(融点)．融点271.3 ℃，沸点1610 ℃．気相では Bi2 分子となる．第一イオン化エネルギー7.289 eV．イオン半径は，Bi3＋(六配位)0.117 nm，Bi5＋(六配位)0.090 nm．Bi3＋/Biの標準電極電位は＋0.32 V で，イオン化傾向は小さい．すべての元素のなかでもっとも反磁性が強く熱伝導率は水銀についで金属中最少である．またビスマスはガリウム同様液体から固化すると，体積が増加(3.5％)する数少ない金属の一つである．酸化力のない酸には溶けないが，硝酸，王水などに溶解し，ビスマス(Ⅲ)塩を生じる．空気中では，高温では燃焼しBi2O3となる．ハロゲンと反応し，BiCl3(白色)，BiBr3(黄金色)，BiI3(緑黒色)，BiF5を生じる．化合物は，酸化数3が通常であるが，酸化数5の化合物は強酸化剤である(例：MⅠBiO3)．
化学的特性
Bismuth is the fifth element in the nitrogen group, and its properties are the most metal-likeof the five. Elemental bismuth is a heavy, brittle, hard metal that can be polished to a brightgray-white coat with a pinkish hue. It is not found in this state very often because it is more likelyto be combined with other metals and minerals, such as tin, lead, iron and cadmium. These aremixtures with low melting points, making them useful in fire-detection devices.
When heated in air, bismuth burns with a blue flame, giving off clouds of its yellow oxide.Bismuth’s melting point is 271.40°C, its boiling point is 1,564°C, and its density is 9.807 g/cm
3.
物理的性質
Bismuth has unusually low toxicity for a heavy metal.
Bismuth is stable to both dry and moist air at ordinary
temperatures. When red hot, it reacts with water to
make bismuth(III) oxide. Bismuth forms trivalent and
pentavalent compounds. The trivalent compounds are
more common. Many of its chemical properties are
similar to those of As and Sb, although they are less toxic
than derivatives of those lighter elements. At elevated
temperatures, the vapors of the metal combine rapidly
with oxygen, forming the yellow trioxide, Bi
2O
3.
同位体
There are a total of 59 radioactive isotopes for bismuth, ranging in half-livesfrom a few milliseconds to thousands of years. At one time it was thought that there wasjust one stable isotope (Bi-209), but it was later found that Bi-209 is radioactive witha half-life of 19,000,000,000,000,000,000 years. Such a long half-life means that Bi-209 has not completely disintegrated and is still found in nature, and is thus consideredstable. In this case, Bi-209 makes up 100% of Bismuth’s natural abundance.
名前の由来
Bismuth was known and used by the ancient alchemists along with
other metals both for chemical reactions and for medical purposes. The name comes
from the German bismu, which had been changed from wismu, meaning “white.”
天然物の起源
Bismuth is the 70th most abundant element, and it is widely spread over the Earth’s crust, butin very small amounts. There are no major concentrated sources. It occurs both in the free elementalstate and in several ores. The major ore, bismuthinite (B
2S
3), is found in South America.
The United States gets most of its bismuth as a by-product from smelting ores of lead,silver, copper, and gold. It is also recovered from the refining of tin and tungsten ores.
特性
Bismuth is more resistant to electrical current in its solid state than it is in its liquid form.Its thermal conductivity is the lowest of all metals, except mercury. Even though it is considereda metal-like element, it is a very poor conductor of heat and electricity.
Bismuth has a characteristic similar to water. It expands when changing from the liquidphase to the solid phase. This factor makes it useful as an alloy in metals that are used to fillmolds, given that it will expand to the cast’s dimensions.
使用
Bismuth is used to make the drugs such as Pepto-Bismol for upset stomachs and diarrheaand in medicine to treat intestinal infections. Bismuth is used in the cosmetics industry toprovide the “shine” for lipsticks, eye shadow, and other products.
It is added to steel and other metals as an alloy to make the metals easier to roll, press, pullinto wires, and turn on a lathe. It is also used in the semiconductor industry and to makepermanent magnets.
Bismuth is similar to antimony in that it expands from the molten liquid state to the solidstate. This property makes it an excellent material to pour into molds and can produce finedetails in whatever is being molded, such as metallic printing type and similar fine castings.
定義
A brittle pinkish metallic element belonging to group 15 (formerly VA) of the periodic table. It occurs native and in the ores Bi
2S
3 and Bi
2O
3. The element does not react with oxygen or water under normal temperatures. It can be dissolved by concentrated nitric acid. Bismuth is widely used in alloys, especially low-melting alloys. The element has the property of expanding when it solidifies. Compounds of bismuth are used in cosmetics and medicines.
一般的な説明
All foils are mounted on a permanent support which cannot be removed without damaging the foil.
危険性
Bismuth is flammable as a powder. The halogen compounds of bismuth are toxic wheninhaled or ingested. Some of the salts of bismuth can cause metallic poisoning in a mannersimilar to mercury and lead.
At the beginning of the twentieth century, before penicillin, bismuth compounds wereused to treat some venereal diseases. However, the treatment was generally unsuccessful.
健康ハザード
Exposures to bismuth salts are associated primarily by ingestion. Bismuth is known to
cause adverse health effects. The symptoms include, but are not limited to, irritation
of the eyes, skin, respiratory tract, lungs, foul breath, metallic taste, and gingivitis.
On ingestion, bismuth causes nausea, loss of appetite, weight, malaise, albuminuria,
diarrhea, skin reactions, stomatitis, headache, fever, sleeplessness, depression, rheumatic pain, and a black line may form on gums in the mouth due to deposition of
bismuth sulfi de. Prolonged exposure to bismuth causes mild but deleterious effects
on the kidneys and high concentrations of bismuth result in fatalities. Occupational
exposures to bismuth occur during the manufacture of cosmetics, industrial chemicals, and pharmaceuticals. Acute exposure with over dosage of bismuth-containing
drugs causes anorexia, nausea, vomiting, abdominal pain, and possibly a dry mouth
and thirst. Bismuth also causes neurotoxicity. Bismuth pentafl uoride is highly toxic
and causes irritation to the skin, eyes, and respiratory tract, while bismuth subnitrate
causes blurred vision.
職業ばく露
Bismuth is used as a constituent of
tempering baths for steel alloys; in low Freezing/Melting
point alloys which expand on cooling; in aluminum and
steel alloys to increase machinability; and in printing type
metal. Bismuth compounds are found primarily in pharmaceuticals
as antiseptics, antacids, antiluetics, and as a
medicament in the treatment of acute angina. They are also
used as a contrast medium in roentgenoscopy and in cosmetics.
For the general population the total intake from food
is 5 20 μg with much smaller amounts contributed by air
and water.
発がん性
An old lifetime study with rats fed 2% bismuth subcarbonate (BSC) in the diet did not show an increase of tumors or a decrease of survival.
環境運命予測
The mechanism by which bismuth produces toxicity has not
been identified. Interaction with thiol compounds has been
proposed as a primary mechanism.
輸送方法
UN3089 Metal powders, flammable, n.o.s.,
Hazard Class: 4.1; Labels: 4.1—Flammable solid.
純化方法
Melt it in an atmosphere of dry helium, then filter through dry Pyrex wool to remove any bismuth oxide present [Mayer et al. J Phys Chem 64 238 1960].
Structure and conformation
The space lattice of Bi belongs to the trigonal system, and its arsenic type structure has lattice constants of a=0.4736 nm, Bi–Bi=0.310 nm, α=57°16', and u=0.474.
不和合性
Finely divided powder is highly flammable.
Reacts with strong acids and strong oxidizers, chlorine,
fused ammonium nitrates, iodine pentafluoride, and nitrosyl
fluoride.
廃棄物の処理
Dissolve in a minimum
amount of concentrated HCl. Dilute with water until precipitate
is formed. Redissolve in HCl. Then saturate with
H2S. Filter, wash, dry and return to supplier.
ビスマス 上流と下流の製品情報
原材料
準備製品