Silvaperl Perlite - Grade P35
SilvaPerl - Graded Industrial Perlite
Expanded perlite is a white, ultra-lightweight aggregate ranging from a very fine powder to an aggregate with a particle size up to 6mm in size. It is inorganic, inert, neutral in pH, biologically stable and has no asbestos content. It has excellent thermal insulation properties over an extremely wide temperature range from cryogenics at minus 273oC (absolute zero) up to refractory applications at over 1000C. It also has a highly adsorbent surface and a very low bulk density which makes it an ideal carrier or low cost filler for many compound formulations.
The source of the ore for the manufacture of perlite is a naturally occurring siliceous volcanic rock. This is quarried, crushed and screened into closely graded fractions.
Perlite is converted into expanded perlite by heating it in a furnace. When quickly heated to above 870oC (1600oF) the crude rock pops in a manner similar to popcorn as the combined water vaporises and creates coutless tiny bubbles in the heat softened glassy particles. It is these tiny glass sealed bubbles which account for the light weight and excellent insulating properties of expanded perlite.
The mineral is an aluminium silicate and under normal conditions is chemically inert.