Why do we measure the magnesium content in talcum powder?
Answers
A mineral which occurs naturally throughout the world. It has a platy structure. Talc is a metamorphic mineral resulting from the metamorphism of magnesian minerals such as serpentine, pyroxene, amphibole, olivine, in the presence of carbon dioxide and water. This is known as talc carbonation or steatization and produces a suite of rocks known as talc carbonates.
Talc is primarily formed via hydration and carbonation of serpentine, via the following reaction;
serpentine + carbon dioxide = talc + magnesite + water
Mg3Si2O5 (OH)4 + 3CO2 ? Mg3Si4O10 (OH)2 + 3 MgCO3 + 3 H2O
Talc can also be formed via a reaction between dolomite and silica, which is typical of skarnification of dolomites via silica-flooding in contact metamorphic aureoles, i.e.,
dolomite + silica + water = talc + calcite + carbon dioxide
CaMg(CO3)2 + 4 SiO2 + H2O = Mg3Si4O10 (OH)2 + 3 CaCO3 + 3 CO2
Synonyms
Hydrous magnesium silicate, (Mg3H2(SiO3)4), talc powder, cosmetic talc, french talc, montana talc, texas talc, vermont talc, industrial talc, tremolitic talc, steatite talc, fibrous non-tremolite talc, no asbestos talc, magnesium silicate talc, talcum, french chalk, soapstone, steatite, CAS# 14807-96-6,
Chemical Properties
Silicon dioxide= 56.3% magnesium ore) Finely ground grades oxide= 30.7% and calcium oxide= 7.0%
Physical Properties
a) Ceramic grade (Coarse, medium & fine)
b) Cosmetic grade
c) Paint grades
d) USP grade
e) Soapstone grade
f) Micronized grade
g) Finely ground grade
Targets, tablets, pieces, granules and various powder granulations sized between 37 microns to 1.5 microns mean particle size
Typical Applications
a) Lubricant, filler, reinforcement, electric and heat insulator, anti stick, anti cake, carrier, thickener, adsorbent, strengthener, ceramics, cosmetics, and pharmaceuticals.
b) Ground talc makes talcum powder. The massive variety (soapstone) is used for sinks, table tops, etc. Soapstone found a use in Babylonian days when signature cylinder seals were often carved from it.
c) The Egyptians also used it as a base for some of their blue faience figurines, which were then fired to fuse the glaze. California Indians also used it as sculpture material.
Packaging
Bags, drums and bulk bags
Specifications
Hegman Grind= 3- 6
Density (g/cm3)= 2.7- 2.85
Specific Gravity= 2.6- 2.85
Oil Absorption= 30-55
RI Values na=1.538 - 1.550 nß=1.575 - 1.594 n?=1.575 - 1.600
Appearance= Translucent, Colorless, White, Pale green, Brown
Surface Area= (m2/g) 4.3
Fracture= Sub-Conchoidal
Mohs Hardness= @20°C 1.0- 1.5
pH= 8.4-9.4
Crystallography= Lamellar / Triclinic
G.E. Brightness= 85- 93
Refractive Index= 1.59- 1.60