Technical Information & Safety Data Sheets

Typical Physical Properties

Color White
Refractive Index 1.5
Free Moisture (max.) 5%
pH (of water slurry) 6.5 - 8.0
Specific Gravity 2.2 - 2.4
Softening Point 1600 - 2000 °F
Fusion Point 2300 - 2450 °F
Specific Heat 0.2 Btu/lb. °F
Thermal Conductivity @ 75 °F 0.27 - 0.41 Btu.in/h.ft2. °F
Bulk Density 2 - 10 lbs./ft3
Mesh Size 4 mesh & finer
Solubility
  • In hot concentrated alkali & HF
  • Moderately (<10%) in 1N NaOH
  • Slightly (<3%) in mineral acid
  • Very slightly (<1%) in water & mineral acids

Typical Elemental Analysis *

Silica 33.8
Aluminum 7.2
Potassium 3.5
Sodium 3.4
Iron 0.6
Calcium 0.6
Magnesium 0.2
Trace 0.2
Oxygen (by difference) 47.5
Net Total 97.0
Bound Water 3.0
TOTAL 100.0

* All analyses are shown in elemental form even though actual forms present are mixed glassy silicates. Free silica may be present in small amounts, characteristic of the particular ore body.

Perlite Institute Member

Since 1954