炭酸ストロンチウム

外観

白色の粉末又は塊

溶解性

希硝酸に溶ける。

解説

炭酸ストロンチウム

天然にはストロンチアン石として産出する．ストロンチウム塩水溶液に炭酸アンモニウムを加えると得られる．また，水酸化ストロンチウムに二酸化炭素を吸収させても得られる．無色の斜方晶系結晶．926 ℃ で六方晶系に転移する．強熱すると二酸化炭素と酸化ストロンチウムとに分解する．水に難溶，塩化アンモニウム水溶液に可溶，エタノールに不溶．酸と反応して二酸化炭素を発生してその酸のストロンチウム塩を生じる．二酸化炭素を含む水には炭酸水素ストロンチウムとなって溶解する．

用途

ブラウン管、花火、信号筒、光学レンズの材料。

用途

超電導材料、フェライト材料。

用途

炭酸ストロンチウムストロンチウム塩の製造，花火(赤色)，変色ガラスの原料，ブラウン管，電子材料，蛍光体磁性材料，砂糖の精製などに用いられる．

炭酸のストロンチウム塩。天然にストロンチアン石として産出する。人工的には、天青石（硫酸ストロンチウム）と炭酸ナトリウムの混合物を融解してつくる。副生した硫酸ナトリウムは水で抽出し除去する。ストロンチウム塩の水溶液に炭酸アンモニウムを加えると、純粋なものを沈殿として得ることができる。加熱すると次の反応によって解離する。

　　SrCO3SrO+CO2

　種々のストロンチウム塩や酸化物、水酸化物の製造原料となる。

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。

説明

Strontium carbonate has the formula of SrCO₃ and the molecular weight of 147.6326 g/mol. Strontium carbonate occurs in nature as the mineral “strontianite”. The name strontianite comes from a famous location for the mineral, Strontian, Scotland. Strontianite is strontium carbonate as found naturally. It occurs as white or slightly gray orthorhombic crystals with a refractive index of 1.518. The unit-cell parameters are: a = 5.107 ? , b = 8.414 ? , c = 6.029 ? , Z = 4; V = 259.07 ? 3, Den(Calc) = 3.78. The crystal system is orthorhombic with space group Pmcn and point group 2/m, 2/m, 2/m. Strontium carbonate has only one stable form (aragonite-type structure) and temperature of precipitation has no effect on crystal form, unlike that of calcium or magnesium carbonates.

化学的特性

Strontium carbonate is a milky white free flowing powder. It is little more insoluble (Ksol=10-8.8) than calcium carbonate (Ksol=10-8.07), so it should not be surprising that under appropriate conditions Sr2+ can be precipitated by biogenic carbonate.

化学的特性

Heating strontium carbonate up from 1000°C to 1300°C causes the compound to undergo a decomposition reaction which results in the capture of thermal energy, shown here as the peak in the black curve occurring between Time = 20 and Time = 40 minutes. Cooling the system back down to 1000°C leads to reconstitution of the starting material in a carbonation reaction thereby releasing the stored thermal energy, a process shown as the valley in the black curve between Time = 50 and Time = 80 minutes.

物理的性質

White orthorhombic crystals; refractive index 1.518; hygroscopic; hardness 3.5 Mohs; density 3.5 g/cm³; insoluble in water; soluble in dilute acids with liberation of carbon dioxide.

天然物の起源

Strontium carbonate occurs in nature as mineral strontianite. The compound is used in pyrotechnics and ceramic ferrites. It also is used in making iridescent glass for color television tubes. Other uses are in refining sugar and preparing other strontium salts.

使用

Strontium carbonate (SrCO3) is used to make radiation-resistant glass and TV picture tubes, as well as pyrotechnics.

定義

strontianite: A mineral form ofstrontium carbonate, SrCO₃.

製造方法

Strontium carbonate occurs in nature as strontianite and can be mined from its deposit. It is, however, usually made commercially from the mineral “celestite”. Celestite is fused with sodium carbonate at elevated temperatures or boiled with a solution of ammonium carbonate.Strontium carbonate is insoluble in water. It precipitates from the product mixture in the second reaction. If fused with sodium carbonate, the product mixture is leached with water. Insoluble carbonate separates from the water-soluble sodium sulfate.

調製方法

Strontium carbonate, formed (1) by reaction of strontium salt solution and sodium carbonate or bicarbonate solution, (2) by reaction of strontium hydroxide solution and CO2. Strontium carbonate decomposes at 1,200 °C (2,192 °F) to form strontium oxide and CO2, and is dissolved by excess CO2, forming strontium bicarbonate, Sr(HCO3)2, solution.

一般的な説明

Strontium carbonate is insoluble in water. It is used predominantly in producing other strontium salts.

一般的な説明

Strontianite is a strontium carbonate mineral (SrCO₃). It is the original and principal source of strontium. It often occurs in white masses of radiating fibres, although pale green, yellow, or gray colours are also known. Strontianite forms soft, brittle crystals that are commonly associated with barite, celestine, and calcite in low-temperature veins. Strontianite is used in pyrotechnics to impart a red colour and in sugar refining as a clarifying agent.