珪灰石 化学特性,用途語,生産方法
解説
硅灰石化学成分CaSiO3の鎖状構造をもつ準輝石に属する三斜晶系の鉱物。比重2.92，モース硬度4.5～5，融点1512℃，白色繊維状あるいは細粒結晶の集合塊。へき開は｛100｝に顕著，｛001｝や｛02｝にも強い。ほかに単斜晶系のパラケイ灰石parawollastoniteをはじめいくつかの多型構造がある。1150℃以上では同質異晶の3員環(SiO3)3構造をもつ偽ケイ灰石pseudowollastoniteに転移する。
説明
“Wollastonite” occurs as a calcium inosilicate
mineral that may contain small amounts of Fe, Mg and
Mn substituting for calcium.
The manufactured salt is
usually white. It forms within the earth when impure
limestone is subjected to high temperature and pressure,
sometimes in the presence of silica-bearing fluids as in
metamorphic rocks. It is named after the English
chemist and mineralogist William Wollaston (1766–
1828).
Wollastonite crystallizes as a triclinic crystal with
the space group, 1, and the lattice constants: a = 7.94? ,
b = 7.32 ? , c = 7.07 ? ; α= 90.03°, β = 95.37°, γ = 103.43°
and six formula units per cell.
化学的特性
White to brown, red, gray, yellow solid;
vitreous to pearly luster. Mohs hardness 4.5–5.
物理的性質
Wollastonite occurs as bladed crystal masses,
single crystals can show an acicular particle shape
and usually it exhibits a white color, but sometimes
cream, gray or very pale green. The melting point of
wollastonite is about 1540°C.
使用
Ceramics; paint extender; welding rod coatings;
rubber filler; silica gels; paper coating; filler
in plastics, cements, and wallboard; mineral wool;
soil conditioner.
定義
A natural calcium silicate found in metamorphic
rocks.
調製方法
Wollastonite is a natural calcium silicate that typically occurs
in deposits with other silicate minerals. When crushed, it
tends to cleave into particles that have length to diameter
ratios of 7 or 8 to 1. Fibrous forms of wollastonite are not
uncommon.
一般的な説明
White or slightly cream-colored powder. pH (aqueous slurry) 8.0 to 10.0.
空気と水の反応
Insoluble in water.
反応プロフィール
These substances undergo chemical reactions only under relatively severe circumstances or in the presence of an effective catalyst that promotes reaction. They are resistant to ignition, although they may become flammable at very high temperatures. They will be resistant to oxidation/reduction, except in the most severe conditions. These materials may be nontoxic.
危険性
Questionable carcinogen
火災危険
Flash point data for CALCIUM SILICATE are not available; however, CALCIUM SILICATE is probably nonflammable.
珪灰石 上流と下流の製品情報
原材料
準備製品