Rock-slag wool

Among 3685 rock-slag wool workers lung cancer incidence was increased (Boffetta et al. 1999). 

From these it can be seen that rock wool, slag wool and glass wool are all mineral wools. 

MMVF are synthetic fibers with glasslike structures. The term usually refers to silicate-based glass fibers, because these compositions form the largest volume of fibers produced. However, in addition to fiberglass and fused silica (Si02), there are other amorphous fibers used in commerce alumina (AI2O3) and silica combinations, rock and slag wool, as well as fibers with nonsilicate compositions such as carbon. Many of these amorphous fibers have proprietary names. 

The fibrous glass used for insulation materials does not require starting materials of high purity. Beach sand, which consists largely of the mineral quartz, is easily obtainable and quite inexpensive. Alternatively, silicate slags or waste rock from mining can be melted and processed to create the products called rock-, slag-, and mineral-wool. Such materials are used for insulation. Where specific properties are desired, such as resistance to ultra-... 

Eastes W., Potter R. M., and Hadley J. G. (2000b) Estimating rock and slag wool fiber dissolution rate from composition. Inhalat. Toxicol. 12, 1127—1139. 

Thin fibers 2 to 10 pm in diameter and with an average length of ca. 15 mm are obtained by the cascade centrifugal process, widely used for the production of rock and slag wools. In this process the melt flows onto one of three to four rotors with horizontal axes. From there the melt is transferred with increasing speed to the casing... 

Continuous glass filament Rock (stone) wool Slag wool Para-Aramid Wollanstonite Sepiolite... 

Mineral wool, also known as rock and slag wool, is made by heating basalt, rhyolite, diabase, or blast furnace slag with limestone. The limestone decomposes and the calcium oxide fluxes the other component to produce a melt. The fluid melt is then discharged into the path of a high pressure jet of steam, which breaks it up into fine threads of mineral fibre. 

Synonyms/Trade Names Manmade mineral fibers, Rock wool, Slag wool. Synthetic vitreous fibers [Note Produced by blowing steam or air through molten rock (rock wool) or various furnace slags that are by-products of metal smelting or refining processes (slag wool).] ... 

As a consequence of their variation in chemical composition, the toxicological properties of MMMF vary over a big range. Their carcinogenic potency increases in the series normal glass wool < rock wool < slag wool < ceramic fibers < asbestos. 

Rock wool and slag wool. These materials are stiU manufactured to varying degrees throughout the world. The raw materials are basalt, basalt in combination with limestone, and blast furnace slag. 

Composition ranges and typical physical properties for wool-type fiberglass compositions (including rock wool and slag wool) are shown in Tables 6.22 and 6.23. 

Advantage high-viscosity and high-Uquidus-temperature glasses such as rock wool and slag wool can be fiberized this way... 

Disadvantage viscosity and hquidus temperature must be low enough for spinning (rock wool and slag wool hquidus temperatures too high to be made by this process)... 

FIGURE 6.39 Mechanical attenuation method for making rock wool and slag wool. [Man-Made Vitreous Fibers Nomenclature Chemical and Physical Properties, Nomenclature Committee of TIMA Inc., p. 17 (Courtesy ofNAIMA—North American Insulation Manufacturers Assoc.).]... 

Rock wool fibers can be characterized by their acidity modulus, Mj, which describes the ratio of acidic to basic oxides. If Ms< 1.2, the fiber is called slag wool, the base material of which is cinder. Nowadays, such low quality fibers are not produced any more because they are very brittle and show a poor chemical resistance. If Mj= 1.2-1.5, the fiber is considered to be a mineral wool, the base materials of which are basic volcanic rock and cinder. These fibers are brittle, but have acceptable insulation properties, hence their significance in the construction industry is high. If Ms> 1.5, the fiber is called rock wool, and if its base material is basalt then it is named basalt wool (basalt fiber, BF). The base of basalt fiber is basalt, which is a volcanic, over-ground, effusive rock saturated with 45-52 wt.% Si02. Due to the circumstances of its formation, basalt has several excellent properties. In addition to its high elasticity modulus and excellent heat resistance. 

E. E. McConnell, O. Kamstrup, R. Musselman, T. W. Hesterbeig, J. Chewalier, W. C. Miller, P. Thevenaz (1994) Chronic inhalation study of size-separated rock and slag wool insulation fibers in Fischer 344/N rats, Inhal. Toxicol. 6,571. 

E-glass Glass wool Rock wool Slag wool Refractory ceramic fiber... 

In rock and slag wool produced from materials melted in a cupola with coke as fuel, all iron oxide is reduced to FeO. Typically, 8-15% of the iron is oxidized to Fc203 during the spinning process. 

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