酸化カドミウム 化学特性,用途語,生産方法
解説
酸化カドミウム,製造法により淡黄色から黄褐色，赤褐色まで変化する．無定形粉末．密度6.95 g cm－3．酸素気流中で長く加熱すると暗赤色の六方晶系の結晶(密度8.15 g cm－3)となる．強熱すると700 ℃ で昇華する．水，アルカリに不溶，酸に易溶，アンモニア水，アンモニウム塩水溶液に可溶．水素および一酸化炭素気流中で加熱すると，還元されて金属カドミウムが得られる．
森北出版「化学辞典（第2版）
用途
顔料、耐食表面処理
用途
カドミニウム鍍金浴の添加剤、電池
応用
カドミウムめっき浴，印刷顔料，光学ガラス，光触媒の製造，半導体材料などに用いられる．
製造
酸化カドミウム,金属カドミウムの燃焼酸化か，カドミウムの水酸化物，炭酸塩，シュウ酸塩，硝酸塩の加熱分解によって得られる．
化学的特性
Cadmium oxide forms brownish-red crystals
or a yellow to dark brown amorphous powder.
物理的性質
Occurs in two forms, alpha form—a colorless amorphous powder, and beta form—a reddish-brown crystal; density 6.95 g/cm
3 (alpha form) and 8.15 g/cm
3 (beta form); decomposes on rapid heating at 900°C; sublimation temperature 1,559°C; insoluble in water and alkalis; dissolves in mineral acids.
使用
Cadmium oxide is used as an electroplating chemical,
catalyst, component of semiconductors, and starting material
for PCV heat stabilizers; in glass and ceramic glazes; for
production of cadmium electrodes in storage batteries; and in
other applications.
調製方法
Cadmium oxide is manufactured commercially by distilling
cadmium metal from graphite retort and allowing vapor to
react with air.
製造方法
Cadmium oxide is prepared by the reaction of cadmium vapor with oxygen. The metal is first melted in a steel retort and transported into a heated chamber where it is vaporized. The vapor is reacted with air, and the cadmium oxide formed is collected in a bag house. The particle size of the product depends on the ratio of air to cadmium vapor. The oxide may be further purified and particles of uniform size may be obtained by calcination at low red heat.
Cadmium oxide also may be prepared by several other routes starting with various cadmium salts. The compound can be made by thermal decomposition of cadmium carbonate or cadmium hydroxide:
CdCO
3 → CdO + CO
2
Cd(OH)
2 → CdO + H
2O
Similar thermal decomposition of cadmium nitrate or sulfate would yield the oxide.
he oxide. Cadmium oxide also may be made by high temperature oxidation of cadmium sulfide:
2CdS + 3O
2 → 2CdO + 2SO
2
Finely divided oxide may be obtained by pyrolysis of cadmium salts of carboxylic acids, such as cadmium formate or oxalate.
(COOH)
2Cd → CdO + H
2O + 2CO
(COO)
2Cd → CdO + CO
2 + CO
一般的な説明
Brown crystals or brown amorphous powder. Used as an electroplating chemical and in the manufacture of cadmium electrodes. Is a component of silver alloys, phosphors, semiconductors, glass and ceramic glazes. Formerly used by veterinarians to kill worms and parasites.
空気と水の反応
Insoluble in water.
反応プロフィール
Cadmium oxide reacts violently with magnesium.
危険性
Inhalation of vapor or fume may be fatal.
A confirmed carcinogen.
健康ハザード
The lethal inhalation dose of Cadmium oxide in humans is 2,500 mg/m3 for a 1 minute exposure. Lethal exposure has been established at 50 mg (cadmium)/m3 for 1 hour for Cadmium oxide dust and 1/2 hour for the fume. These concentrations may be inhaled without sufficient discomfort to warn worker of exposure. Inhalation may cause acute tracheobronchitis, pneumonitis, and pulmonary edema. Exposure can cause kidney and lung damage. Acute exposure by inhalation may cause death by anoxia. The lowest human toxic inhalation concentration is 8.630 mg/m3/5 hours for the fume. Persons with respiratory disorders should be excluded from contact with Cadmium oxide.
火災危険
When heated to decomposition, Cadmium oxide emits toxic fumes of cadmium. (Non-Specific -- Cadmium Compounds) Fire may produce irritating or poisonous gases. Runoff from fire control or dilution water may cause pollution. Oxides of cadmium react explosively with magnesium when heated.
安全性プロファイル
Confirmed human
carcinogen with experimental neoplastigenic
data. Poison by ingestion, inhalation, and
intraperitoneal routes. An experimental
teratogen. Other experimental reproductive
effects. Human systemic effects by
inhalation include: change in the sense of
smell, change in heart rate, blood pressure
increase, an excess of protein in the urine,
and other kidney or bladder changes.
Mixtures with magnesium explode when
heated. When heated to decomposition it
emits toxic fumes of Cd. See also
CADMIUM COMPOUNDS.
職業ばく露
Cadmium oxide is used as an electroplating chemical and in the manufacture of semiconductors
and cadmium electrodes; synthesis of other cadmium salts;
a component of silver alloys, phosphorus, glass and
ceramic glazes, semiconductors, and batteries. Used as a
vermicide
輸送方法
UN2570 Cadmium compounds, Hazard Class:
6.1; Labels: 6.1-Poisonous materials, Technical Name
Required.
不和合性
Oxides of cadmium react explosively
with magnesium, especially when heated. Heat above
700C causes slow decomposition. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); light metals:
contact may cause fires or explosions. Keep away from
alkaline materials, strong bases, strong acids, oxoacids,
epoxides, hydrogen sulfide, hydrazine nitrate. May ignite
combustibles, such as wood, paper, oil, etc
廃棄物の処理
Form nitrate with HNO3, precipitate with H2S, filter, package and return to supplier.
酸化カドミウム 上流と下流の製品情報
原材料
準備製品