Mineral wool
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Mineral wool is any
Applications of mineral wool include thermal insulation (as both structural insulation and pipe insulation), filtration, soundproofing, and hydroponic growth medium.
Naming
Mineral wool is also known as mineral fiber, mineral cotton, mineral fiber, man-made mineral fiber (MMMF), and man-made vitreous fiber (MMVF).
Specific mineral wool products are stone wool and slag wool. Europe[who?] also includes glass wool which, together with ceramic fiber, are entirely artificial fibers that can be made into different shapes and are spiky to touch.
History
Slag wool was first made in 1840 in
According to a mineral wool manufacturer, the first mineral wool intended for high-temperature applications was invented in the United States in 1942 but was not commercially viable until approximately 1953. More forms of mineral wool became available in the 1970s and 1980s.[4]
High-temperature mineral wool
High-temperature mineral wool is a type of mineral wool created for use as high-temperature insulation and generally defined as being resistant to temperatures above 1,000 °C. This type of insulation is usually used in industrial furnaces and foundries. Because high-temperature mineral wool is costly to produce and has limited availability, it is almost exclusively used in high-temperature industrial applications and processes.[citation needed]
Definitions
Classification temperature is the temperature at which a certain amount of linear contraction (usually two to four percent) is not exceeded after a 24-hour heat treatment in an electrically heated laboratory oven in a neutral atmosphere. Depending on the type of product, the value may not exceed two percent for boards and shaped products and four percent for mats and papers.
The classification temperature is specified in 50 °C steps starting at 850 °C and up to 1600 °C. The classification temperature does not mean that the product can be used continuously at this temperature. In the field, the continuous application temperature of amorphous high-temperature mineral wool (AES and ASW) is typically 100 °C to 150 °C below the classification temperature. Products made of polycrystalline wool can generally be used up to the classification temperature.[citation needed]
Types
There are several types of high-temperature mineral wool made from different types of minerals. The mineral chosen results in different material properties and classification temperatures.
Alkaline earth silicate wool (AES wool)
AES wool consists of amorphous glass fibers that are produced by melting a combination of calcium oxide (CaO−), magnesium oxide (MgO−), and silicon dioxide (SiO2). Products made from AES wool are generally used in equipment that continuously operates and in domestic appliances. Some formulations of AES wool are bio-soluble, meaning they dissolve in bodily fluids within a few weeks and are quickly cleared from the lungs.[5][6]
Alumino silicate wool (ASW)
Alumino silicate wool, also known as refractory ceramic fiber (RCF), consists of amorphous fibers produced by melting a combination of aluminum oxide (Al2O3) and silicon dioxide (SiO2), usually in a weight ratio 50:50 (see also VDI 3469 Parts 1 and 5,[7] as well as TRGS 521). Products made of alumino silicate wool are generally used at application temperatures of greater than 900 °C for equipment that operates intermittently and in critical application conditions (see Technical Rules TRGS 619).[citation needed]
Polycrystalline wool (PCW)
Polycrystalline wool consists of fibers that contain aluminum oxide (Al2O3) at greater than 70 percent of the total materials and is produced by sol–gel method from aqueous spinning solutions. The water-soluble green fibers obtained as a precursor are crystallized by means of heat treatment.[7] Polycrystalline wool is generally used at application temperatures greater than 1300 °C and in critical chemical and physical application conditions.
Kaowool
Kaowool is a type of high-temperature mineral wool made from the mineral
Manufacture
Stone wool is a furnace product of
Use
Though the individual fibers
Other uses are in
Mineral fibers are produced in the same way, without binder. The fiber as such is used as a raw material for its reinforcing purposes in various applications, such as friction materials, gaskets, plastics, and coatings.
Material | Temperature |
---|---|
Glass wool | 230–260 °C |
Stone wool | 700–850 °C |
Ceramic fiber wool |
1200 °C |
Hydroponics
Mineral wool products can be engineered to hold large quantities of water and air that aid root growth and nutrient uptake in hydroponics; their fibrous nature also provides a good mechanical structure to hold the plant stable. The naturally high pH of mineral wool makes them initially unsuitable to plant growth and requires "conditioning" to produce a wool with an appropriate, stable pH.[12]: 16 Conditioning methods include pre-soaking mineral wool in a nutrient solution adjusted to pH 5.5 until it stops bubbling.
High-temperature mineral wool
High-temperature mineral wool is used primarily for insulation and lining of industrial furnaces and foundries to improve efficiency and safety. It is also used to prevent the spread of fire.[5]
The use of high-temperature mineral wool enables a more lightweight construction of
Safety of material
The
High bio soluble fibers are produced that do not cause damage to the human cell. These newer materials have been tested for carcinogenicity and most are found to be noncarcinogenic. IARC elected not to make an overall evaluation of the newly developed fibers designed to be less bio persistent such as the alkaline earth silicate or high-alumina, low-silica wools. This decision was made in part because no human data were available, although such fibers that have been tested appear to have low carcinogenic potential in experimental animals, and because the Working Group had difficulty in categorizing these fibers into meaningful groups based on chemical composition.[14]
The European Regulation (CE) n° 1272/2008 on classification, labelling and packaging of substances and mixtures updated by the Regulation (CE) n°790/2009 does not classify mineral wool fibers as a dangerous substance if they fulfil criteria defined in its Note Q.
The European Certification Board for mineral wool products, EUCEB, certify mineral wool products made of fibers fulfilling Note Q ensuring that they have a low bio persistence and so that they are quickly removed from the lung. The certification is based on independent experts' advice and regular control of the chemical composition.
Due to the mechanical effect of fibers, mineral wool products may cause temporary skin itching. To diminish this and to avoid unnecessary exposure to mineral wool dust, information on good practices is available on the packaging of mineral wool products with pictograms or sentences. Safe Use Instruction Sheets similar to Safety data sheet are also available from each producer.
People can be exposed to mineral wool fibers in the workplace by breathing them in, skin contact, and eye contact. The Occupational Safety and Health Administration (OSHA) has set the legal limit (permissible exposure limit) for mineral wool fiber exposure in the workplace as 15 mg/m3 total exposure and 5 mg/m3 respiratory exposure over an 8-hour workday. The National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit (REL) of 5 mg/m3 total exposure and 3 fibers per cm3 over an 8-hour workday.[15]
Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) is a European Union regulation of 18 December 2006. REACH addresses the production and use of chemical substances, and their potential impacts on both human health and the environment. A Substance Information Exchange Forum (SIEF) has been set up for several types of mineral wool. AES, ASW and PCW have been registered before the first deadline of 1 December 2010 and can, therefore, be used on the European market.
- ASW/RCF is classified as carcinogen category 1B.
- AES is exempted from carcinogen classification based on short-term in vitro study result.
- PCW wools are not classified; self-classification led to the conclusion that PCW are not hazardous.
On 13 January 2010, some of the aluminosilicate refractory ceramic fibers and zirconia aluminosilicate refractory ceramic fibers have been included in the candidate list of
Regardless of the concerns raised, the inclusion of a substance in the candidate list triggers immediately the following legal obligations of manufacturers, importers and suppliers of articles containing that substance in a concentration above 0.1% (w/w):
- Notification to ECHA -REACH Regulation Art. 7
- Provision of Safety Data Sheet- REACH Regulation Art. 31.1
- Duty to communicate safe use information or responding to customer requests -REACH Regulation Art. 33
Crystalline silica
Amorphous high-temperature mineral wool (AES and ASW) is produced from a molten glass stream which is aerosolized by a jet of high-pressure air or by letting the stream impinge onto spinning wheels. The droplets are drawn into fibers; the mass of both fibers and remaining droplets cool very rapidly so that no crystalline phases may form.
When amorphous high-temperature mineral wool is installed and used in high-temperature applications such as industrial furnaces, at least one face may be exposed to conditions causing the fibers to partially devitrify. Depending on the chemical composition of the glassy fiber and the time and temperature to which the materials are exposed, different stable crystalline phases may form.
In after-use high-temperature mineral wool
Substitutes for mineral wool in construction
Due to the mineral wool non-degradability and potential health risks, substitute materials are being developed:
See also
- Asbestos, a mineral that is naturally fibrous
- Basalt fiber, a mineral fiber having high tensile strength
- Glass wool
- Pele's hair
- Risk and Safety Statements
References
- ^ "Man-made mineral fibre (MMMF) is a generic name used to describe an inorganic fibrous material manufactured primarily from glass, rock, minerals, slag and processed inorganic. The MMMF produced are non-crystalline (glassy, vitreous, amorphous)." [1] Recommendation from the Scientific Committee on Occupational Exposure Limits for man made-mineral fibres (MMMF) with no indication for carcinogenicity and not specified elsewhere
- ^ Spon, Ernest. Workshop Receipts ... London: E. & F. N. Spon, 18831892. Page 439
- ^ a b "Mineral Wool or Mineral Cotton", Appleton's Annual Cyclopedia and Register of Important Events of the Year 1891. New Series vol. 16. New York: 1892. 528. Print.
- ^ a b "HISTORY OF HTIW PRODUCTS". Archived from the original on 2018-08-19. Retrieved 2018-08-08.
- ^ a b "High temperature insulation wool - Production, Properties, Classification". insulatioNet.com. Retrieved 2018-06-24.
- ^ "Biosolubility FAQ's". ICANZ. Retrieved 2019-01-19.
- ^ a b VDI Guideline: VDI 3469 Part 1 - Overview Part 5 – High-Temperature Insulation Wool
- ^ "Thermal Ceramics" (PDF).
- ^ Weiner, Ethan. Acoustic Treatment and Design for Recording Studios and Listening Rooms. "Without question, the most effective absorber for midrange and high frequencies is rigid fiberglass."http://www.ethanwiner.com/acoustics.html#rigid%20fiberglass.
- ^ Houghton, Matt. Sound On Sound. "What is the best density for a good, fairly wide-spectrum absorber? . . .try looking for mineral wool in the region of 45-75kg/m3." http://www.soundonsound.com/sos/oct10/articles/qa-1010-2.htm
- ^ "SuperFOIL Foil Insulation Roll 0.6m x 25m - Energy Saving DIY Bubble Foil Sheet - 3-in-1 Sustainable Thermal Insulation Reflective Radiant Barrier & Vapour Barrier - Multi Purpose for Home & Auto : Amazon.co.uk: DIY & Tools". Amazon UK.
- ISBN 978-0-944557-01-3.
- ^ IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Volume 81 (2002), Man-made Vitreous Fibres (PLEASE NOTE: Some manufacturers of insulation products[who?] have cited this volume while making erroneous claims that "IARC scientists confirm safety of mineral wool insulation". These claims are just false. The findings in this volume are not a determination of non-carcinogenicity or overall safety.)
- ^ IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Volume 81 (2002), Man-made Vitreous Fibres, Overall evaluation, p. 339
- ^ "CDC – NIOSH Pocket Guide to Chemical Hazards – Mineral wool fiber". www.cdc.gov. Retrieved 2015-11-27.
- ISSN 0868-8257.
External links
- Statistics Canada documents on shipments of mineral wool in Canada
- Review of published data on exposure to mineral wool during installation work by A Jones and A Sanchez Jimenez, Institute of Occupational Medicine Research Report TM/11/01
- Assessment of airborne mineral wool fibres in domestic houses by J Dodgson and others. Institute of Occupational Medicine Research Report TM/87/18