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Calcium Metasilicate (Wollastonite) Synonyms:
Calcium metasilicate, wollastonite, tabular spar, table spar, CAS#13983-17-0, okenite, vilnite, rivaite, schalstein, gillebachite, aedelforsite
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Calcium Metasilicate (Wollastonite) Designations:
Chemical Name: Calcium metasilicate
Chemical Formula: CaSiO3 or CaO.SiO2
a) Calcium Metasilicate is a white to yellowish-brown naturally occurring mineral. It has good strength, firing characteristics and ability to reduce crazing. It is comprised chemically of calcium, silicon and oxygen. It's molecular formula can be expressed as CaSiO3 or as CaO.SiO2. It is commonly referred to as calcium metasilicate according to the now obsolete classification of silicates as oxyacids of silicon, a salt of hypothetical metasilicic acid: H2SiO3. It has a theoretical composition of 48.28% CaO and 51.72% SiO2.
b) Natural Calcium Metasilicate however, may contain trace or minor amounts of various metal ions such as aluminum, iron, magnesium, manganese, potassium and sodium. Any of these ions may partially substitute for calcium if they are present.
c) Calcium Metasilicate is rarely found by itself, and ore zones in the major deposits contain 20-98% wollastonite. Associated minerals are most often calcite, garnet, and diopside.
Theoretical composition: CaO= 48.3% and SiO2= 51.7%. The typical is: CaO= 47.0% and SiO2= 50.0%
Various granulations are available. Primarily 10 X 100 mesh, 200 mesh X down and 325 mesh X down
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Molecular Weight (g/mol.)
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116
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Density (lbs./solid gallons)
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24.2
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Specific Gravity
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2.8- 2.9
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Specific Heat @25°C (cal/g-°C)
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Melting Point (°C)
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1540
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Boiling Point (°C)
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G. E. Brightness
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85-93
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Thermal Conductivity @20°C (cal/s-cm-°C)
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Mohs Hardness @20°C
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4.5- 5.0
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pH (aqueous solution)
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9- 10
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Crystallography
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acicular
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Color
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white
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Oil Absorption
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22- 45
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Refractive Index
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1.63
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Hegman Grind
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4- 7
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a) As a source of silica and alkalis in the production of ceramics. Used to produce wall tiles, semivitreous bodies, ceramic insulators and glazes, thermoplastics, adhesives, and ceramic-bonded abrasives.
b) Calcium Metasilicate has been found useful as a soil conditioner and an additive to plant fertiliser for it’s reactivity in acid conditions. As opposed to lime or calcite, it offers long-term protection against the acidification of soils.
c) In some countries, Calcium Metasilicate has also found use as an inert carrier for pesticides and insecticides.
Drums, bulk bags or loose bulk
Listed. For further information please call the U. S. Environmental Protection Agency at +1.202.554.1404
CAS# 13983-17-0
253090
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