カルシウムオキシド 化学特性,用途語,生産方法
外観
白色の粉末
定義
本品は、カルシウムの酸化物であり、次の化学式で表される。
溶解性
水に微溶 (0.13g/100g,10℃)
解説
酸化カルシウム，化学式 CaO 。石灰，生石灰ともいう。工業的には石灰岩を加熱して製造。通常白色ないし灰白色で，塊状または粒状の物質。融点 2572℃，沸点 2850℃，比重約 3.2。空気中では容易に水と二酸化炭素を吸収する。水に溶け，水酸化カルシウム Ca(OH)2 を生じ，同時に強く発熱する。グリセリン，砂糖溶液に可溶。煉瓦，モルタル，しっくいなどの建材用原料，ガラス，紙，アンモニア・ソーダ法 (ソルベー法) による炭酸ソーダの製造，鉄鋼，アルミニウム，マグネシウムの精錬，各種カルシウム塩や工業化学製品の製造，ショ糖，ビート糖液の脱色，殺虫・殺菌剤，下水処理，炭酸ガス吸収剤などに使われ，用途は非常に多い。強アルカリ性物質で皮膚，粘膜をおかすので，粉末などを吸入することは危険。特に目に入ると，水分や蛋白質と発熱反応を起して糊状の塊をつくる。これを洗い落すことは普通の洗浄では非常にむずかしい。
用途
鉄鋼製造用,大気汚染防止?排水処理用,パルプ?紙製造用,カーバイド原料,マグネシアクリンカー?金属マグネシウム製造原料,建築土壌安定用,医薬用,農薬 (NITE CHRIP)
用途
脱水剤、乾燥剤、鉄鋼及びカーバイト工業等の原料。
用途
高純度金属化合物。
化粧品の成分用途
pH調整剤
効能
乾燥剤
使用上の注意
空気中で二酸化炭素及び水分を吸収する。
化学的特性
Calcium oxide, CaO, occurs as white or
grayish-white lumps or granular powder. The presence of iron
gives it a yellowish or brownish tint.
物理的性質
Calcium oxide is a white caustic crystalline alkali substance that goes by the common name lime. The term lime is used both generically for several calcium compounds and with adjectives to qualify different forms of lime. This entry equates lime, also called quicklime or burnt lime, with the compound calcium oxide. Hydrated lime, made by combining lime with water, is calcium hydroxide and is often referred to as slaked lime (Ca(OH)
2). Dolomite limes contain magnesium as well as calcium. Limestone is the compound calcium carbonate. The term lime comes from the Old English word l?m for a sticky substance and denotes lime’s traditional use to produce mortar. Calx was the Latin word for lime and was used to name the element calcium.
来歴
Calcium oxide dates from prehistoric times. It is produced by heating limestone to drive off carbon dioxide in a process called calcination: CaCO
3(s) CaO
(s) + CO
2(g). At temperatures of several hundred degrees Celsius, the reaction is reversible and calcium oxide will react with atmospheric carbon dioxide to produce calcium carbonate. Efficient calcium oxide production is favored at temperatures in excess of 1,000°C. In prehistoric times limestone was heated in open fires to produce lime. Over time, lined pits and kilns were used to produce lime. Brick lime kilns were extensively built starting in the 17th century and the technology to produce lime has remained relatively constant since then.
使用
Calcium Oxide is a general food additive consisting of white granules
or powder of poor water solubility. it is obtained by heating limestone
(calcium carbonate) in a furnace. it is also termed lime or quicklime.
it is used as an anticaking agent, firming agent, and nutritive supple-
ment in applications such as grain products and soft candy.
定義
ChEBI: Calcium oxide is a member of the class of calcium oxides of calcium and oxygen in a 1:1 ratio. It has a role as a fertilizer.
調製方法
Calcium oxide is commercially obtained from limestone. The carbonate is roasted in a shaft or rotary kiln at temperatures below 1,200°C until all CO
2 is driven off. The compound is obtained as either technical, refractory or agri cultural grade product. The commercial product usually contains 90 to 95% free CaO. The impurities are mostly calcium carbonate, magnesium carbon ate, magnesium oxide, iron oxide and aluminum oxide.
製造方法
生石灰(せいせっかい)ともいう。天然の石灰石や炭酸カルシウムを約900℃以上で熱分解すると得られる。
CaCO3―→CaO＋CO2
現在工業的にはほとんど重油を燃料とした立炉や回転炉が用いられる。低温で焼成したものは白色無定形の固体であるが、焼成温度が高くなると結晶性はよくなる。融解液から大きな結晶が得られる。Ca2+イオンとO2-イオンが塩化ナトリウム型の格子をつくっている。格子定数a＝4.80Å、結合間隔Ca-O＝2.40Å。無定形のものはきわめて活性で、水とは高熱を発して反応し、水酸化カルシウム（消石灰）となる。これを消和slakingという。
一般的な説明
Calcium oxide appears as an odorless, white or gray-white solid in the form of hard lumps. A strong irritant to skin, eyes and mucous membranes. Used in insecticides and fertilizers.
空気と水の反応
Crumbles on exposure to moist air. Reacts with water to form corrosive calcium hydroxide, with evolution of much heat. Temperatures as high as 800° C have been reached with addition of water (moisture in air or soil). The heat of this reaction has caused ignition of neighboring quantities of sulfur, gunpowder, wood, and straw [Mellor 3: 673 1946-47].
反応プロフィール
A base and an oxidizing agent. Neutralizes acids with generation of heat. Nonflammable, but will support combustion by liberation of oxygen, especially in the presence of organic materials. Reacts very violently with liquid hydrofluoric acid [Mellor 2, Supp. 1:129 1956]. Reacts extremely violently with phosphorus pentaoxide when reaction is initiated by local heating [Mellor 8 Supp.3:406 1971].
危険性
Evolves heat on exposure to water. Danger-
ous near organic materials. Upper respiratory tract
irritant.
健康ハザード
Causes burns on mucous membrane and skin. Inhalation of dust causes sneezing.
火災危険
Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Vapors may accumulate in confined areas (basement, tanks, hopper/tank cars etc.). Substance will react with water (some violently), releasing corrosive and/or toxic gases and runoff. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated or if contaminated with water.
化学性质
白色固体で，水と反応すると発熱し，水酸化カルシウム（消石灰）になる。
农业用途
Calcium oxide (CaO) is a white powder with a
neutralizing value or calcium carbonate equivalent
(CCE) of 179%, compared to 100% for calcium
carbonate (CaCO
3). For quick results, either calcium
oxide or calcium hydroxide [Ca(OH)
2] is used. Calcium
oxide is also known as lime, unslaked lime, burned lime
or quicklime. Roasting CaCO
3 in a furnace makes
calcium oxide. A complete mixing of calcium oxide with
soil is difficult because it cakes due to absorption of
water.
工業用途
Lime is the most widely used reagent in the mineral industry for flotation of sulfides and, in some cases, non-sulfide minerals. The word “lime” is a general term used to describe any kind of calcareous material or finely divided form of limestone and dolomite. In more strict chemical terms, lime is calcinated limestone known as calcium oxide (CaO), quicklime or unslaked lime.The slaked or hydrated lime Ca(OH)2 is the form of lime primarily used in mineral flotation. Production of high-calcium lime is based on calcination of limestone at a temperature of 1100–1300 °C in kilns.
CaCO3+heat--->CaO+CO2 For high-magnesium (dolomitic) limestone, the calcination reaction (at 1000–1200 °C) is CaCO3·MgCO3 (limestone) + heat--->CaOMgO (quicklime-2CO2)
安全性プロファイル
A caustic and irritating
material. See also CALCIUM
COMPOUNDS. A common air
contaminant. A powerful caustic to living
tissue. The powdered oxide may react
explosively with water. Mixtures with
ethanol may igmte if heated and thus can
cause an air-vapor explosion. Violent
reaction with (I3203 + CaCl2) interhalogens
(e.g., BF3, CIF3), F2, HF, P2O5 + heat, water.
Incandescent reaction with liquid HF.
Incompatible with phosphoms(V) oxide.
職業ばく露
Calcium oxide is used as a refractory
material; a binding agent in bricks; plaster, mortar, stucco,
and other building materials. A dehydrating agent, a flux in
steel manufacturing, and a labora
輸送方法
UN1910 Calcium oxide, Hazard class: 8; Labels:
8-Corrosive material.
合成方法
石灰石または炭酸カルシウムを900?1000℃に焼成して製造される。
不和合性
The water solution is a medium strong
base. Reacts with water, forming calcium hydroxide and
sufficient heat to ignite nearby combustible materials.
Reacts violently with acids, halogens, metals.
廃棄物の処理
Pretreatment involves neutralization with hydrochloric acid to yield calcium chloride.
The calcium chloride formed is treated with soda ash to
yield the insoluble calcium carbonate. The remaining brine
solution may be discharged into sewers and waterways
参考文献
W. Gerlach, Z. Physik, 9, 184 (1922), DOI: 10.1007/BF01326966.
カルシウムオキシド 上流と下流の製品情報
原材料
準備製品