カドミウムスルフィド 化学特性,用途語,生産方法
解説
硫化カドミウム，CdS(144.48)．天然には，硫カドミウム鉱として産出する．炭酸カドミウムあるいは酸化カドミウムと硫黄との融解反応か，カドミウム塩の水溶液に硫化水素を通すと得られる．融解反応で得られたものは橙色の六方晶系ウルツ鉱型構造．密度4.82 g cm－3．窒素気流中980 ℃ で昇華する．融点1750 ℃(1000 atm)．水溶液から沈殿するものは鮮黄色の立方晶系せん亜鉛鉱型構造．密度4.58 g cm－3．沈殿型を硫黄気流中で熱すると六方晶系になる．水にほとんど不溶，希酸，硫化アンモニウム，硫化アルカリに不溶，熱希硝酸，熱硫酸に可溶．黄色の顔料(カドミウム黄)，絵の具やペイントの着色成分，蛍光材料，露光計，電子写真感光剤，光触媒などに用いられる．有毒．
用途
・無機カドミウム化合物の製造用
・乾式精錬によるカドミウムの製造用
主な用途／役割
赤色用無機系着色剤。
化学的特性
Cadmium sulfide is an odorless, crystalline,
lemon yellow to orange solid.
物理的性質
Yellow to orange crystal; occurs as two polymorphs, hexagonal alpha form and cubic beta form; exhibits stable wurtzite structure at lower temperature, and zinc blende type structure at higher temperatures; the beta form converts to alpha form when heated at 750°C in sulfur atmosphere; sublimes at 980°C; practically insoluble in water (1.3 mg/L at 20°C); Ksp 3.6x10-29; dissolves in dilute mineral acids on heating or concentrated acids at ordinary temperatures (decomposes with liberation of H
2S).
天然物の起源
Cadmium sulfide occurs in nature as the mineral greenoktite. The compound is widely used in pigments for paints, baking enamels, ceramics and plastics. It imparts bright yellow to maroon, with strong retention of color and resistance to alkalis. It also is used in inks, phosphors, and fluorescent screens. Other applications of this compound are in photovoltaic and solar cells (for converting solar energy to electrical energy), photoconductors (in xerography), thin film transistors and diodes, rectifiers, scintillation counters, pyrotechnics, and smoke detectors.
使用
cadmium sulfide is used as a colorant for paints and rubber; cadmium acetate is used in the production of craftware.
調製方法
Cadmium sulfide may be prepared by the reaction between
hydrogen sulfide and cadmiumvapor at 800 Cor by heating a
mixture of cadmium or cadmium oxide with sulfur.
定義
A native cadmium sulfide containing 77.7% cadmium. Ore of cadmium
製造方法
Cadmium sulfide may be prepared by precipitation from an aqueous solution of its soluble salts such as cadmium chloride or cadmium nitrate by passing hydrogen sulfide. The reactions may be carried out in acidic, neutral or alkaline solutions using various cadmium salts to obtain different crystal modifications as shown in the table below.
Cadmium sulfide also may be obtained by treatment of sodium or other alkali metal sulfide solution with that of a soluble cadmium salt. The compound also may be prepared by heating a mixture of cadmium or its oxide with sulfur at 800°C; or by the reaction of H
2S with cadmium vapor at 800°C.
一般的な説明
Natural occurrence: hawleyite (structural type of sphalerite) and greenockite (structural type of wurtzite)
危険性
A confirmed carcinogen, highly toxic. See
cadmium.
安全性プロファイル
Confirmed human
carcinogen with experimental carcinogenic
and tumorigenic data. Moderately toxic by
ingestion and inhalation. Human mutation
data reported. When heated to
decomposition it emits very toxic fumes of
Cd and SOx. See also CADMIUM
COMPOUNDS and SULFIDES
職業ばく露
Used in pigments; as an active ingredient in dandruff shampoos; making photoconductors, solar
cells, and other electronic components.
輸送方法
UN2570 Cadmium compounds, Hazard Class:
6.1; Labels: 6.1-Poisonous materials, Technical Name
Required.
Structure and conformation
Cadmium sulfide takes two types of structure, zinc blend and wurtzite structures.
Cubic system that has a zinc-blend structure, with a lattice constant of a=0.582 nm and Cd– S=0.252 nm.
Hexagonal system that has a wurtzite structure with lattice constants of a=0.4136 nm, c=0.6713 nm and c/a=1.624, Cd–S=0.252 nm.
不和合性
Contact with water or moisture releases
poisonous hydrogen sulfide gas. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause
廃棄物の処理
Use a licensed professional
waste disposal service to dispose of this material. All federal, state, and local environmental regulations must be
observed. Consult with environmental regulatory agencies
for guidance on acceptable disposal practices. Generators
of waste containing this contaminant (≥100 kg/mo) must
conform to EPA regulations governing storage, transportation, treatment, and waste disposa
カドミウムスルフィド 上流と下流の製品情報
原材料
準備製品