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一、基本概念石棉是具有纤维结构并能分解成微细纤维的特殊矿物。它是一种结合型二氧化硅。按化学成份来说,石棉分两类,即蛇纹石类和角闪石类。蛇纹石类主要为温石棉,化学成份3MgO·2SiO_2·2H_2O。目前世界上石棉95％是温石棉。角闪石类主要有直闪石[7MgO·8SiO_2·H_2O]、青石棉[NaFe(SiO_3)_2·FeSiO_3]、铁石棉(同青石棉,但不合钠而含铝)、透闪石[CaMg_3(SiO_3)_4]等。温石棉表面由Mg(OH)_2组成,酸度增加时,镁离子从表面除去,硅表面暴露出来。表面正电荷使温石棉从溶液中吸引负电荷。角闪石与石英一样,在水中表面带负电荷。石棉不易燃,但在加热情况下也受到影响,如温石棉在427℃下重量丧失2.17％,其中水分损失15％,但仍保留可弯曲性。角闪石丧失水份多且变
First, the basic concept Asbestos is a special mineral fiber structure can be broken down into fine fibers. It is a bonded silica. By chemical composition, asbestos divided into two categories, namely serpentine and amphibole. Serpentine is mainly chrysotile, chemical composition 3MgO · 2SiO_2 · 2H_2O. 95% of asbestos in the world is chrysotile. Amphiboles include mainly amphibole [7MgO · 8SiO_2 · H_2O], crocidolite [NaFe (SiO_3) _2 · FeSiO_3], asbestos (crocidolite but not sodium and aluminum), tremolite [CaMg_3 SiO_3) _4] and so on. Chrysotile surface by the Mg (OH) _2 composition, the acidity increases, the magnesium ions removed from the surface, the silicon surface is exposed. The positive surface charge causes chrysotile to draw a negative charge from the solution. Amphiboles, like quartz, are negatively charged on the surface of water. Asbestos is not flammable, but it is also affected by heating, such as chrysotile loss of 2.17% by weight at 427 ° C, of which 15% moisture loss, but still retains bendability. Amphiboles lost water more and change