DENISFATIN

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vermiculite

pagi ini gue beresin lemari.
gue baru pindahan kamar ceritanya :D

pas ngobrak-ngabrik hanger di lemari, gue menemukan sebungkus pewangi lemari -yang gue baru inget-dulu, gue beli di ace hardware sama mba inda.

karena udah ngga wangi lagi, akhirnya gue iseng buka bungkusannya. dengan gunting.
pas gue buka, gue agak sedikit bingung dengan serpihan bubuk kasar yang ada didalamnya. mirip kayu tapi warnanya lebih metalik. empuk dan lebih mirip kaya busa, karena pas gue pencet, langsung gembos.

lalu gue liat komposisinya. dibungkusnya tertulis: vermiculite 90% and fragrance 10%

vermiculate? apa itu?

VERMICULITE

Vermiculite is a natural mineral that expands with the application of heat. The expansion process is called exfoliation and it is routinely accomplished in purpose-designed commercial furnaces. Vermiculite is formed by weathering or hydrothermal alteration of biotite or phlogopite. Large commercial vermiculite mines currently exist in Russia, South Africa, China, and Brazil

Occurrence
Vermiculite was first described in 1824 for an occurrence in Millbury, Worcester County, Massachusetts, USA. Its name is from Latin vermiculare, to breed worms, for the manner in which it exfoliates when heated.
It typically occurs as an alteration product at the contact between felsic and mafic or ultramafic rocks such as pyroxenites and dunites. It also occurs in carbonatites and metamorphosed magnesium rich limestone. Associated mineral phases include: corundum, apatite, serpentine and talc. It occurs interlayered with chlorite, biotite and phlogopite.

Structure
Vermiculite is a 2:1 clay, meaning it has 2 tetrahedral sheets for every one octahedral sheet. It is a limited expansion clay with a medium shrink-swell capacity. Vermiculite has a high cation exchange capacity at 100-150 meq/100 g. Vermiculite clays are weathered micas in which the potassium ions between the molecular sheets are replaced by magnesium and iron ions.

Commercial uses
moulded shapes bonded with sodium silicate for use in:
high-temperature insulation
refractory insulation
fireproofing of structural steel and pipes
soil conditioner
as loose-fill insulation
packing material, valued for its high absorbency
suitable as a substrate for various animals and/or incubation of eggs
lightweight aggregate for plaster, proprietary concrete compounds, firestop mortar and cementitious spray fireproofing
as an additive to fireproof wallboard
component of the interior fill for firestop pillows, along with graphite
carrier for dry handling and slow release of agricultural chemicals
soil additive for plants, together with perlite for potted plants
growing medium for hydroponics.
means to permit slow cooling of hot pieces in glassblowing, lampwork, steelwork, and glass beadmaking
used in in-ground swimming pools to provide a smooth pool base
used in commercial hand warmers
used as a sterile medium for the incubation of reptile eggs
light-weight insulative concrete
used in AGA cookers as insulation
used in explosives storage as a blast mitigant
used to absorb hazardous liquids for solid disposal
used in gas fireplaces to simulate embers
used as a coating/impregnation on fiberglass sleeve, tape, rope and fabric to increase the useful temperature range and to add abrasion resistance. (http://www.vermiculitecoated.com
used as part of a substrate for fungi cultivation


Commercial manufacture of exfoliated vermiculite
While some exfoliators focus on only a few of the possible applications, others can provide vermiculite products for all its applications. It is common for vermiculite exfoliators to exfoliate perlite also, as both are often sold together. For those who want to set up a new exfoliation process, it is possible to find expert consultants to advise in the design and construction of the desired facilities. Vermiculite exfoliators have an international trade association called The Vermiculite Association to represent the industry’s interests and to exchange information.[4] Many of its members also maintain memberships in The Perlite Institute.


Fireproofing
For many years, since the advent of the asbestos removal business, before which nearly everyone sold asbestos-based spray fireproofing, vendors could be cleanly categorized into users of MMMF (man-made-mineral-fibres), which included both rockwool and ceramic fibres, and cementitious sprays, whereby the binder was typically Portland cement and the lightweight aggregate inside the plaster was vermiculite. For many years, makers of the cementitious products would point out the ill health effects that are possible from overexposure and lack of proper industrial hygiene procedures when working with MMMF.[citation needed] Vendors of the MMMF products would point out the possibility of asbestos contamination, particularly with US mined vermiculite ore. Ironically, both sides were defending against lawsuits in the asbestos litigation and eventually stopped pointing out these particular weak spots about one another. Most affected manufacturers are still in receivership as a means of dealing with the results of the asbestos litigation.

Asbestos contamination
Although not all vermiculite contains asbestos, some products were made with vermiculite that contained asbestos until the early 1990s. Vermiculite mines throughout the world are now regularly tested for it and are supposed to sell products that contain no asbestos. The former vermiculite mine in Libby, Montana, did have tremolite asbestos as well as winchite and richterite (both fibrous amphiboles) — in fact, it was formed underground through essentially the same geologic processes as the contaminants. A vermiculite mine in Virginia has also been found to be contaminated by asbestos.
Pure vermiculite does not contain asbestos and is non-toxic, but it can become contaminated over long periods if there is a presence of a secondary mineral called diopside. After millions of years of weathering, the biotite turns into vermiculite and the diopside turns into asbestos.

Controversy over health risks
The largest and oldest vermiculite mine in the United States was started in the 1920s, at Libby, Montana, and the vermiculite was sold under the commercial name Zonolite. The Zonolite brand and the mine was acquired by the W.R. Grace Company in 1963. Mining operations at the Libby site stopped in 1990 in response to asbestos contamination. While in operation, the Libby mine may have produced 80% of the world’s supply of vermiculite.
The United States government estimates that vermiculite was used in more than 35 million homes, but does not recommend its removal. Nevertheless, homes or structures containing vermiculite or vermiculite insulation dating from before the mid 1990s—and especially those known to contain the “Zonolite” brand—may contain asbestos, and therefore may be a health concern.
An article published in the Salt Lake Tribune on December 3, 2006, reported that vermiculite and Zonolite had been found to contain asbestos, which had led to cancers such as those found in asbestos-related cases. The article stated that there had been a “cover-up” by W.R. Grace Company and others regarding the health risks associated with vermiculite and that several sites in the Salt Lake Valley had been remediated by the EPA when they were shown to be contaminated with asbestos. W.R. Grace Company has vigorously denied these charges.
The vermiculite deposit at the mine in Libby, Montana, was (and is) heavily contaminated with asbestos. Numerous people were knowingly exposed to the harmful dust of vermiculite that contained asbestos. Unfortunately, the mine had been operating since the 1920s, and environmental and industrial controls were virtually non-existent until the mine was purchased by the W.R. Grace Company in 1963. Yet, knowing the human health risks, the mining company still continued to operate there until 1990. Consequently, many of the former miners and residents of Libby have been affected and continue to suffer health problems. Over 200 people in the town have died from asbestos-related disease due to contamination from vermiculite mining from nearby Zonolite Mountain, where soil samples were found to be loaded with fibrous tremolite (known to be a very toxic form of asbestos), and countless others there who insulated their homes with Zonolite have succumbed to asbestos-related diseases, most of whom never were employed in environments where asbestos was an issue.
After a 1999 Seattle Post-Intelligencer story claimed that asbestos-related disease was common in the town, the EPA, in response to political pressure, made cleanup of the site a priority and called Libby the worst case of community-wide exposure to a toxic substance in U.S. history.The EPA has spent $120 million in Superfund money on cleanup. In October 2006, W. R. Grace Company tried to appeal the fines levied on them from the EPA, but the Supreme Court rejected the appeal. The United States government is also pursuing criminal charges against several former executives and managers of the mine for allegedly disregarding and covering up health risks to employees. They are also accused of obstructing the government’s cleanup efforts and wire fraud. To date, according to the indictment, approximately 1,200 residents of the Libby area have been identified as suffering from some kind of asbestos-related abnormality. Jury selection was to have been completed in February, 2009. The case ended in acquittals on May 8, 2009.On June 17, 2009, the EPA issued a public health emergency in and near Libby, thereby allowing Federal agencies to provide funding for health care, and for removal of contaminated insulation from affected homes.

  • 26 January 2011
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