Mineral wool

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. 

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Minerals separation Mineral violet Mineral wool Minerec Mines... 

Metal Pan Assemblies. These units consist of tiles and panels formed from perforated aluminum or steel with pads of fiber glass or mineral wool inserted into the pans to provide the sound absorption. They are used primarily for ceilings in a similar manner to acoustical tiles and panels. The pads are sometimes sealed in plastic film to prevent absorption of moisture, dirt, and odors. The perforated metal is relatively sound transparent and functions as the finished ceiling and the support for the sound-absorbing material. The perforated metal by itself has no acoustical value. 

Custom decorative sound-absorbing treatments for wall surfaces are frequentiy used in auditoriums and theaters, especially for control of echoes from rear walls. Typical treatments consist of prefabricated or custom-built wood grilles over fiber glass or mineral wool blankets or batts. 

Sound-Absorptive Blankets. Sound-absorptive blankets of fiber glass or mineral wool are not usually considered damping materials, but when fastened to sheet metal machine enclosures they can provide some useful damping in addition to sound absorption. 

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. 

Insulation provides other functions in addition to energy conservation. A key role for insulation is safety. It protects personnel from bums and minimizes hot surfaces that could ignite inflammables. It also protects equipment, piping, and contents in event of fire. Thus materials such as mineral wool are sometimes used despite relatively poor thermal quaUties. 

Container Insulation Tanks containing materials above atmospheric temperature may require insulation to reduce loss of heat. Almost any of the commonly used insulating materials can be employed. Calcium silicate, glass fiber, mineral wool, cellular glass, and plastic foams are among those used. Tanks exposed to weather must have jackets or protective coatings, usually asphalt, to keep water out of the insulation. 

Other Considerations Autoignition can occur if combustible fluids are absorbed by wicking-type insulations. Chloride stress corrosion of austenitic stainless steel can occur when chlorides are concentrated on metal surfaces at or above approximately 60°C (140°F). The chlorides can come from sources other than the insulation. Some calcium sihcates are formulated to exceed the requirements of the MIL-I-24244A specification. Fire resistance of insulations varies widely. Calcium sihcate, cellular glass, glass fiber, and mineral wool are fire-resistant but do not perform equally under actual fire conditions. A steel jacket provides protection, but aluminum does not. 

Internally insulated ducts Coated mineral wool 0.25... 

AX = insulation thickness, ft K. = insulation thermal conductivity, Btu/hr-ft- F = 0.03 for mineral wool... 

Calcium silicate Foam glass Mineral wool... 

Mineral Wool Calcimn Silicate Foam Glass ... 

Domestic roofs U = 0.25W/m K 150 mm mineral wool loft insulation... 

Medium- to heavy-density mineral wool mat with wire netting or expanded metal mechanically secured on one or both sides. Mattress-type products are used for irregular-shaped surfaces and on large pipes and vessels. It is also used as large-cavity fire barriers. 

Brown Kraft paper is generally used on mineral wool products to give added tensile strength, ease handling, aid positive location between studs or rafters, or prevent contamination when used under concrete screeds. Paper is often laminated with polyethylene to give vapor control layer properties. 

Paper- or foil-backed mineral wool product fabricated from low-density slabs in which the slats stand upright with the fibers predominantly perpendicular to the major faces. This type of product is used on circular and elliptical ducting, pipes and vessels to give a compression-resistant insulant. Supplied in roll form. 

Nodulated mineral wool produced for application through pneumatic hoses into areas of restricted access. 

Generally used with mineral wool products where, in its decorative forms, it gives attractive facings to ceilings and wall tiles and enhances their sound-absorption characteristics. PVC is also used as a vapor control layer facing. 

Glass-fiber tissue or non-woven fabrics are used for decorative purposes on many insulants. They also give improved strength to foam plastics and enhanced sound-absorption characteristics to mineral wools. 

Used to give mechanical strength to mineral wool mattresses and is an aid to application. Also a key for mastic or hard setting finishes applied on site. 

Mineral wool is perhaps the best known of the whole range of insulation types. It is widely used in all sectors of industry, transport and building for thermal, acoustic and fire-protection purposes. There is a common misconception that mineral wool is a specific product type - it is not. Mineral wool is a generic name for a range of man-made non-metallic inorganic fibers. The following definitions should help to clarify the situation ... 

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

Glass wool A mineral wool produced from molten glass. 

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