長石 化学特性,用途語,生産方法
定義
本品は、主にケイ酸アルミニウムカリウムからなる天然鉱物である。
解説
長石，最も重要な造岩鉱物。化学組成がCa，Na，Kなどのアルミノケイ酸塩からなる鉱物の一群で，フレームワーク（網状）構造をもつケイ酸塩鉱物として代表的なもの。ふつう成分を表すのにOr＝KAlSi3O8（カリ長石），An＝CaAl2Si2O8（灰長石），Ab＝NaAlSi3O8（ソウ長石）などの記号を用い，AbとAnはあらゆる割合で固溶体（斜長石）をつくる。まれにCe＝BaAl2Si2O8（重土長石）の組成の長石もある。単斜晶系または三斜晶系で，どちらの場合もへき開の完全な短柱状結晶を示し，へき開面でいろいろな双晶をつくる。物理的性質はきわめて類似した共通性を示し，硬度６〜6.5，比重2.56〜2.76，色は白色または黄・淡紅・淡緑色など。高温型と低温型があり，前者は火山岩中に，後者は他の岩石中にみられる。長石はほとんどすべての火成岩中で重要な役割を果たし，長石の組成によって火成岩が分類される。変成岩においても主要構成鉱物であり，砂質堆積岩にも相当量含まれる。変質作用によって絹雲母，カオリンなどの粘土鉱物に変わる。
化粧品の成分用途
増量剤、着色剤
使用
Pottery, enamel, and ceramic ware; glass; soaps; abrasive; bond for abrasive wheels; cements and concretes; insulating compositions; fertilizer; poultry grit; tarred roofing materials.
主な応用
Feldspar is e xtensively used in scouring and cleaning compounds and for a window cleaner.
定義
General name for a group of sodium, potassium, calcium, and barium aluminum silicates. Commercially, feldspar usually refers to the potassium feldspars with the formula KAlSi 3O8, usually with a little sodium. Noncombustible.
危険性
Toxic as fine-ground powder.
农业用途
Feldspars, a group of silicate materials, are the most abundant minerals in the earth's crust. Feldspars have a structure in which (SiAl)O
4 tetrahedral is linked together with potassium, sodium and calcium. Occasionally, barium ions also occupy large spaces in the same framework. Commercially, feldspar usually refers to potassium feldspar with the formula KA1Si
3O
8. This feldspar has little sodium.
The chemical composition of feldspars may be expressed as combinations of (a) anorthite (CaAl
2Si
2O
8), (b) albite (NaAlSi
3O
8),（c) orthoclase (KAlSi
3O
8), and (d) celcian (BaAl
2Si
2O
8).
Feldspars form colorless, white or pink crystals with a hardness of 6 on the Mho's scale. They are used in pottery, cement and concrete, insulating compositions, fertilizers and glass.
Feldspars are subdivided into two groups. One of them is alkali feldspar (including microcline, orthoclase and sanidine) which has a significant amount of potassium, a smaller proportion of sodium and negligible calcium. The other group, namely plagioclase feldspar, varies in composition from pure sodium feldspar (albite) to pure calcium feldspar (anorthite) with negligible amounts of potassium.
工業用途
Feldspars (Al
2O
3 and SiO
4 tetrahedra) constitute60% of the outer 13 to 17 km of the earth’scrust and are the most common mineral in crystallinerocks. Feldspars are aluminum silicatesof potassium, sodium, and calcium.
The importance of the many feldspars thatoccur so widely in igneous, metamorphic, andsome sedimentary rocks cannot be underestimated,especially from the viewpoint of apetrologist attempting to unravel Earth history.
With weathering, feldspars form commerciallyimportant clay materials. Economically.feldspars are valued as raw material for theceramic and glass industries, as fluxes in ironsmelting, and as constituents of scouring powders.Occasionally, their luster or colors qualifythem as semiprecious gemstones. Some decorativebuilding and monument stones are predominantlycomposed of weather-resistantfeldspars.
Knowledge of the composition of a feldsparand its crystal structure is indispensable to anunderstanding of its properties. However, it isthe distribution of the aluminum and siliconatoms among the available tetrahedral sites ineach chemical species that is essential to a completeclassification scheme, and is of greatimportance in unraveling clues to the crystallizationand thermal history of many igneous andmetamorphic rocks.
長石 上流と下流の製品情報
原材料
準備製品