WHAT IS PERLITE
Perlite is an inorganic siliceous ore. The distinguishing feature of perlite is its expansibility of approximately 10 times when heated over 800 C°. Perlite contains crystallised water that is evaporated when heated creating numerous microscopic air hollows that provide the insulation’s characteristics. The LBD (Loose Bulk Density) of dry perlite is approximately 1-1.1tons/m³ whereas the LBD of the expanded perlite may have 60-500Kg/ m³ according to the end usage.
• 70–75% silicon dioxide: SiO2
• 12–15% aluminium oxide: Al2O3
• 3–4% sodium oxide: Na2O
• 3–5% potassium oxide: K2O
• 0.5-2% iron oxide: Fe2O3
• 0.2–0.7% magnesium oxide: MgO
• 0.5–1.5% calcium oxide: CaO
• 3–5% loss on ignition
USES OF PERLITE
The uses of perlite can be divided to three major categories. Construction applications, agricultural applications and industrial applications.
The major market for expanded perlite is the construction market due to its high thermal and sound insulation characteristics and its low bulk density. Perlite does not deteriorate through time or climate changes and also is practically inflammable. The applications of perlite in the construction market are:
• In mortars (either cement based or gypsum based)
• In lightweight concrete
• As a loose filling insulation
Expanded Perlite is widely used in the agricultural market as an ingredient in peat soil providing the appropriate conditions for leafy and flowering pots. Expanded Perlite provides the ideal ratio of air and water but also the required drainage.
Expanded Perlite has also been used in Hydroponic growth systems providing excellent results due to it’s neutral PH and the low saturation compared with other materials.
With its unique characteristics perlite has wide and diversified usages in the industry some of them are:
• Unexpanded and expanded perlite is also used in Foundries. Unexpanded perlite is used as a mean to attract all the impurities. Expanded perlite is used as an insulator for reducing heat losses and is also used for high quality alloys.
• Another use of expanded perlite is for the absorption of waste oils and oil spills in the sea.
• Perlite is also used in soap, toothpaste and detergents due to its abrasive characteristics.