Talc is the world's softest mineral. Although all talc ores are soft, platy, water repellent and chemically inert. Talc is a vital part of everyday life. The magazines we read, the polymers in our cars and houses, the paints we use and the tiles we walk on are just some of the products that talc enhances. Talc is a hydrated magnesium sheet silicate. Talc is practically insoluble in water and in weak acids and alkalis. It is neither explosive nor flammable. Although it has very little chemical reactivity, talc does have a marked affinity for certain organic chemicals. And it is organophilic. Above 900°C, talc progressively loses its hydroxyl groups and above 1050°C. Talc's melting point is at 1500°C.
Specifications
1
Loss on Ignition
4% to 6%
2
Loss on Drying
0.05%
3
Acid soluble substances (as SO4)
2% to 3%
4
Extractable Fluoride
0.2% to 20%
5
pH (at 10%)
8.5% to 9.5%
6
Soluble Salts
0.2%
7
Absorption in Oil
30 to 35
8
Asbestos Fibers
Nil
9
Arsenic
Nil
10
SiO2
60 to 67
11
MgO
29 to 32
12
Fe2O3
0.15
13
CaO
As per requirement
14
Al2O3
0.6% to 1%