Iron sulfide - Iron sulfide

A sulfide ore of iron. In Japan, pyrite (FeS ₂ ) is the most prevalent, so this is usually what is referred to. [ I ] Pyrite and marcasite: FeS ₂ (53.46% S, whereas ores contain 35-50% S). It transforms from marcasite (orthorhombic crystals) to pyrite (cubic crystals) at 450°C. Marcasite is highly reactive, producing iron sulfate (II) and sulfuric acid even in air and at room temperature, but pyrite is stable. Pyrite occurs as regular hexahedral, regular octahedral, and pentagonal dodecahedral crystals, and is found mixed in the host rock. Marcasite occurs as spear-shaped, radial crystals, and is found mixed with pyrite and sulfur. [CAS 12068-85-8][CAS 1309-36-0:pyrite][CAS 1317-66-4:marcasite] [ II ] Pyrrhotite: Fe _{1- x} S (equivalent to FeS or Fe ₇ S ₈ , S is 39.34% as Fe ₇ S _8. S is 25-30% in pyrrhotite ore). Ignition temperature is high at 500°C, but it is unstable and may spontaneously combust. Used as a raw material for sulfur dioxide production. [CAS 12518-96-6]

Source: Morikita Publishing "Chemical Dictionary (2nd Edition)" Information about the Chemical Dictionary 2nd Edition

鉄の硫化物鉱．日本では黄鉄鉱(pyrite)FeS₂がおもなので，通常，これをさす．【Ⅰ】黄鉄鉱および白鉄鉱：FeS₂(S 53.46％，鉱石で産出するものはS 35～50％)．白鉄鉱(斜方晶)から450 ℃ で黄鉄鉱(等軸晶)へ転移する．白鉄鉱は空気中，常温でも硫酸鉄(Ⅱ)，硫酸を生じ反応性に富むが，黄鉄鉱は安定である．黄鉄鉱は正六面体，正八面体，五角十二面体結晶で，母岩にまざって産出する．白鉄鉱はやり状，放射状結晶で，黄鉄鉱，硫黄とまざって産出する．[CAS 12068-85-8][CAS 1309-36-0:pyrite][CAS 1317-66-4:marcasite]【Ⅱ】磁硫鉄鉱(pyrrhotite)：Fe_1－xS(FeSまたはFe₇S₈に相当，Fe₇S₈としてはS 39.34％．磁硫鉄鉱の鉱石ではS 25～30％)．着火温度は500 ℃ と高いが，不安定で自然発火のおそれがある．二酸化硫黄製造原料に用いられる．[CAS 12518-96-6]

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