Perlite is a naturally occurring siliceous colcanic glass lava containing combined water, falling into the category of igneous rock. The distinguishing feature which sets perlite apart from other volcanic glasses is that when heated to a suitable point in its softening range, it expands from four to twenty times than its original volume. Expanded perlite can be manufactured to weigh as little as 70kg per cubic meter making it adaptable for numerous applications, for example: Construction, horticulture and industrial applications.

1. Crude perlite ore:
Index A B C
SiO2(%) 72.59 72.59 72.23
Al2O3(%) 12.63 12.46 12.31
K2O(%) 4.74 4.65 4.67
Na2O(%) 3.45 3.45 3.29
Others(%) 6.59 6.46 7.5
Specific gravity 2.26 2.4 2.32
Hardness(HV) 648 643 652
Expansion rate K0≥ 15 K0≥ 15 K0≥ 18
Expa-temperature 1000-1200 1050-1250 1200-1300
Pre-heating 300-400 300-400 >350-420

Pitchstone:
SiO2 (%) AI2O3(%) Fe2O3(%) CaO(%) MGO(%) K2O(%)
72.40 12.60 1.08 1.23 0.30 3.87
Na2O(%) TiO2 (%) H2O(%) B. D. (g/l) Expa-temperature Expansion Rate(K0)
3.27 0.17 5.06 1100 1050-1200 ≥ 18

Obsidian:
Component SiO2 Fe2O3 FeO H2O
Content(%) 72.52 0.59 0.39 4.11

Expanded Perlite:
Grade B. D. Moisture Size Thermal Conductivity
Kg/m 3 % % W(m. K) (kcal/m. H. ° C)
Max Max 5mm Above 0.15mm under Average Temperature: 298 ± 5k Temperature Grads: 5-10k/cm
Max Max Max
Grade A Grade B Grade C Grade A Grade B Grade C
70 70 2 2 2 4 6 0.047(0.040) 0.049(0.042) 0.051(0.044)
100 100 0.052(0.045) 0.054(0.046) 0.056(0.048)
150 150 0.058(0.050) 0.060(0.052) 0.062(0.053)
200 200 0.064(0.055) 0.066(0.057) 0.068(0.058)
250 250 0.070(0.060) 0.072(0.062) 0.074(0.064)

Perlite filter aid:
pH Value Water Digestion(%) Acid Digestion(%) Lead(%) Arsenic(ppm) Fe2O3(%) Ignition Loss(%)
7.2 0.14 1.60 0.0015 1.5 0.7 0.96