三硫化ニアンチモン

化学的特性Antimony trisulfide is soluble in alkalies and in concentrated, but not dilute, hydrochloric acid. It also goes into solution if it is boiled in alkali carbonate solutions. However, it precipitates as a reddish-brown powder, of nondefinite oxygen content (kermesite), when the solution is cooled. It forms thioantimonates if it is dissolved in alkali-metal sulfides. Antimony trisulfide is a starting material for the production of antimony and antimony compounds.

解説三硫化二アンチモン：Sb2S3(339.72)．硫化アンチモン(Ⅲ)ともいう．天然に輝安鉱として産出する．アンチモン(Ⅲ)化合物の水溶液に硫化水素を通じて生じるものは不安定型の赤色の固体で，金属アンチモンと硫黄を融解して得られるものは黒色の金属光沢をもつ，融点550 ℃ の安定型の斜方晶系結晶である．不安定型は，二酸化炭素中で200 ℃ に加熱すると安定型になる．水にほとんど不溶．濃塩酸，濃硫酸，硝酸により分解されアンチモン(Ⅲ)塩となる．水酸化アルカリまたは硫化アルカリに溶け，それぞれ，オキソジチオアンチモン(Ⅲ)酸塩MⅠ3SbOS2またはトリチオアンチモン(Ⅲ)酸塩MⅠ3SbS3となる．また多硫化アルカリ水溶液からは，テトラチオアンチモン(Ⅴ)酸塩MⅠ3SbⅤ S4を生じる．マッチの成分，花火，顔料，色ガラス，プラスチックの着色料に用いられる．

用途減磨剤、花火、ガラス清澄剤。

天然物の起源Antimony trisulfide occurs in nature primarily as the mineral, stibnite, which consists of two parallel Sb4S6 chains linked together. It is used in fireworks; in certain types of safety matches; as a pigment in paints; and in the manufacture of ruby glass.

使用Antimony(III) sulfide is used as a red dye in rubber vulcanization. It is used as catalyst, additive, anti- blushing agent, heat stabilizer and used in the production of ruby-colored glass and in plastics as a flame retardant.

Ores with more than 40 – 60 % Sb2S3 and free from lead and arsenic often are beneficiated by heating. Because stibnite, Sb2S3, has an unusually low melting point, 546 – 548 ℃, it can be separated from the gangue by melting (liquation). Stibnite more than 90 % pure is obtained and is referred to as crude antimony. It can be sold as such for producing antimony compounds, or it can be converted to antimony metal.The commercial product should have a striated crystalline structure and a metallic gloss, and its color should be that of graphite. These properties are attained only if the molten antimony(III) sulfide is cooled very slowly. Ores with less than 40 – 45% Sb2S3 are unsuitable for liquation because the large amount of gangue interferes and too much antimony is retained in the residue.The ore is best fed in the form of walnutsized lumps (1 – 4 cm). If the ore is too fine, the molten Sb2S3 does not flow. The most suitable temperature range is 550 – 660 ℃ because the volatilization of the Sb2S3 (bp 1000 ℃) is prevented, and liquation is successful. Liquation is carried out in a reducing atmosphere in crucibles or in reverberatory furnaces. The main impurities in crude antimony are arsenic, lead, and iron sulfide.

製造方法The pure sulphide is obtained from its ore. Stibnite is separated from other ores by grinding and flotation. The ore is then heated to 550-600°C in a perforated vessel. The pure molten material is collected and cooled. It is also prepared by passing hydrogen sulfide into a solution of antimony trichloride:2 SbCl3 + 3 H2S → Sb2S3 + 6 HClor treating antimony trichloride solution with sodium thiosulfate.Alternatively, heating antimony metal or antimony trioxide with sulfur forms antimony trisulfide:2 Sb + 3 S → Sb2S32 Sb2O3 + 9 S → 2 Sb2S3 + 3 SO2All these above preparative methods yield amorphous antimony trisulfide.