Mineral fiber

The most important fiber material among the mineral fibers is asbestos (AS), which had been used as early as 2500 years ago. The largest mining areas can be found in Russia (46% market share), China and Kazakhstan (16% each), Brazil (10%), and Canada (8%). The fibers are extracted from rocks and can be spun into yarns. The yarns can then be processed into wovens, knits, and other textile fabrics. The fibers can also be added to other materials such as concrete and are very suitable for insulation (Kiilter et al, 1990a). 

Compared to natural and chemical fibers, asbestos fibers are extremely fine. The diameter of the elementary fibers varies between 0.02 and 0.2 pm. Further advantages of asbestos are its high-temperature stability and low cost. For these reasons, large amounts of asbestos have been mined and processed worldwide. In 1987, the world production was approximately 4 million tons, but this amount has declined in recent years. 

Fine asbestos dust and fine dust containing asbestos are considered to be carcinogenic. In this case, the size of the dust corns and the fibers and not the asbestos material itself poses the problem. For this reason, the use of asbestos in Germany 

---

Minelbite Mineral dusts Mineral feed Mineral fibers Mineral fillers Mineralization Mineralizers... 

Rock wool, frequently referred to as mineral fiber, is made from non virgin siUceous materials and is formed in a similar manner to that of fiber glass. Refractory fibers (qv), also formed in a similar manner, are available for high temperature appHcations. 

Other Shingle Products. Making up about 20% of the steep market are wood shingles and shakes, concrete and clay tiles, natural and mineral fiber slates, and various styles of metal products (34). 

Slate. Used for hundreds of years, slate comes from different geographical areas and varies in color and weight. Slate (36) is easily spHt to size and shape the most common is 4.76-cm (3/ 16-in.) thick and can weigh 31.71 kg/m (650 lb/100 ft ) or more. Imitation products of mineral fiber and cement stimulate its durabiUty and style. 

Minerals Synthetic mineral fibers Synthetic organic fibers... 

For example, in bulk appHcations as thermal insulation, synthetic mineral fibers (glass or slag fibers) have adequately replaced natural asbestos fibers. In sprayed insulation coatings, asbestos fibers have been replaced, for example, by vermicuhte. As replacement for asbestos textiles, clothing made from aramid fibers or aluminized glass fibers is being offered (see High PERFORMANCE FIBERS). 

Table 8. Exposure Limits for Asbestos Fibers, Synthetic Mineral Fibers (SMF) and Nuisance Dust in the Workplace ...

International Symposium on Man-made Mineral Fibers ia the Working Environment," Copenhagen, Denmark, Oct. 28—29, 1986, Occup. Hjg. 31, 4B (1987). 

Bag An extended surface filter in the form of a pocket or bag. A typical example of a bag filter is a mineral fiber bag made up of three layers, in which the first layer acts as a prefilter, the second is for fine filtration, and the third prevents fiber migration from the material used. 

Environmental tobacco smoke (ETS) is the diluted mixture of pollutants caused by smoking of tobacco and emitted into the indoor air by a smoker. Constituents of ETS include submicron-size particles composed of a large number of chemicals, plus a large number of gaseous pollutants. Fibers in indoor air include those of asbestos, and man-made mineral fibers such as fiberglass, and glass wool. 

The spray is based upon either a natural plate-like material, such as vermiculite bound together with cement, or mineral fibers. Application is fast but not precise or clean, and is generally only suitable for areas where the steel will be hidden (by a false ceiling, for example). Sprays for external applications are available. However, the steel must first be provided with a compatible corrosion protection system. 

Mineral fiber A generic term for all non-metallic inorganic fibers. 

Mineral wool A generic term for mineral fibers of a woolly consistency normally made from molten glass, rock or slag. 

Acid-Soluble Mineral Fibers. Mineral fibers that are highly soluble in acid can be used to control the permeability [1242,1243] of formations. The fibers are 5 to 15 p in diameter and are formed into pellets of to inch diameter. A fluid-blocking layer formed of semidispersed pellets can bridge the face pores of the formation. After well rework, the plugging layer is treated with an acid solution to quickly dissolve the mineral fibers to the desired extent to control porosity. 

F. Montgomery, S. Montgomery, and P. Stephens. Method of controlling porosity of well fluid blocking layers and corresponding acid soluble mineral fiber well facing product. Patent US 5222558, 1993. 

Few words in a contractor s vocabulary carry more negative connotations than asbestos. According to the Asbestos Network, touted as a miracle substance, asbestos is the generic term for several naturally occurring mineral fibers mined primarily for use as fireproof insula-... 

Mineral fibers, 24 613 Mineral-filled composites, 10 452 Mineral fillers, 11 311-313 Mineralization, defined, 3 757t Mineralizers, 14 83 19 403, 405 organic, 14 101-102 Mineralogical information gathering,... 

In this book we define inorganic fibers in a general sense as small elongate solid objects composed of any compound or element usually nonbio-logic in origin and often exhibiting distinctive physical, especially mechanical, properties. Inorganic fibers can occur naturally, that is, as mineral fibers or can be produced synthetically. 

The most common, and certainly the most familiar, inorganic fibers are the mineral fibers known as asbestos. Several minerals have been mined as asbestos (Fig. 1.1 A, C see chapter 2 for a detailed discussion of the asbestos minerals). These minerals are widespread in nature, but mining is economical only when they occur as continuous fibrous aggregates (veins) crosscutting rock masses. The veins are made up of hairlike fibers in parallel array that, on close inspection, appear bent (Fig. I.IB). Not surprisingly, a mineralogical term, asbestiform, has been used to describe this subset of inorganic materials. 

The enhanced strength of whiskers and natural fibers, by comparison to the strength of materials of the same composition in another morphology, could be a coincidental in these crystalline synthetic and mineral fibers, a particular crystal direction is parallel to the direction of the applied stress. However, the inverse diameter-strength relationship indicates that factors other than crystal structure contribute to the mechanical strength of fibrous materials. 

---