Mineral fibers aluminosilicate

Aluminosilicate Fibers. Vitreous alurninosihcate fibers, more commonly known as refractory ceramic fibers (RCF), belong to a class of materials known as synthetic vitreous fibers. Fiber glass and mineral wool are also classified as synthetic vitreous fibers, and together represent 98% of this product group. RCFs were discovered in 1942 (18) but were not used commercially until 1953. Typical chemical and physical properties of these materials are shown in Table 3. 

SILICATE AND ALUMINOSILICATE MINERALS THAT FORM FIBERS... 

The minerals that adopt a fibrous morphology based on structural characteristics are certainly not confined to single- and double-chain aluminosilicates. To illustrate the variety of stmctural configurations that may produce fibers, we briefly outline other mineral groups in the following sections. 

The discrepancy in numbers between natural and synthetic varieties is an expression of the usefulness of zeolitic materials in industry, a reflection of their unique physicochemical properties. The crystal chemistry of these aluminosilicates provides selective absorbtion and exchange of a remarkably wide range of molecules. Some zeolites have been called molecular sieves. This property is exploited in the purification and separation of various chemicals, such as in obtaining gasoline from crude petroleum, pollution control, or radioactive waste disposal (Mumpton, 1978). The synthesis of zeolites with a particular crystal structure, and thus specific absorbtion characteristics, has become very competitive (Fox, 1985). Small, often barely detectable, changes in composition and structure are now covered by patents. A brief review of the crystal chemistry of this mineral group illustrates their potential and introduces those that occur as fibers. 

From every chemical group mentioned in Dana s System of Mineralogy there are minerals that form as fibers. We began with the most commonly encountered minerals, the silicate and aluminosilicate groups, and now briefly mention a few from other chemical classes. 

We have recorded 388 minerals (Appendix 1) that occur, at least occasionally, as fibers some minerals are found only in fibrous form. This number includes more than 92 silicate and aluminosilicate species, most of them common rock-forming minerals. This list, only a fraction of the 3000 minerals known, probably represents only a sampling of naturally occurring fibers. 

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