Perlite is one of the more intriguing building materials that has garnered increasing interest among many investors in recent years. It is a completely natural raw material produced from volcanic rocks subjected to the expansion process. The resulting material is chemically inert, and its insulating properties can rival even the best graphite-based polystyrene.
What is perlite and how is its production process carried out?
Perlite is a natural volcanic raw material typically found in underground deposits. Open-pit mining is employed to extract these deposits, yielding a rock aggregate as the exploited product. The extracted ore is crushed and then transported to specialized refining facilities.
In its natural environment, this raw material forms through the rapid cooling of lava and the accompanying hydration process. As a result, a material with high water content is produced, imparting intriguing physical properties.
One such property is its ability to expand, resulting in a significant, sometimes several-fold increase in volume. This process involves heating perlite to temperatures ranging from 850 to 1000°C. During this procedure, water molecules trapped in the raw material begin to boil, and the resulting steam seeks an outlet. This softens and expands the perlite, giving it a distinctive porous structure.
Upon completion of the perlite expansion process, a hard granulate is obtained that is chemically and biologically neutral. Depending on requirements, it can be used as a semi-finished product in the manufacturing processes of other materials or employed as a finished industrial raw material.
What is perlite used for?
Due to its technical properties, perlite finds applications in various industries. One of its more prevalent uses is in the construction industry. Expanded perlite granulate is employed, among other purposes, for insulating walls constructed with ceramic blocks by filling the inter-rib spaces and addressing voids in the floor insulation layer.
Perlite is also a component in numerous construction products, with perlite blocks and prefabricated elements being notably popular for systematic wall construction. Perlite granulate can also be found in gypsum plasters and high-quality heat-insulating mortars.
Another industry that extensively utilizes perlite is horticulture. Fine perlite granulate serves as an additive to soil mixes, increasing their volume and regulating water and airflow. Due to its biological neutrality and pH-neutral reaction, perlite can also be used as a substrate for hydroponic cultivation.
Furthermore, expanded perlite is employed in heavy industry and metallurgy as an insulator for industrial furnaces and casting molds. It also serves as a pollution absorbent. Perlite granulate is utilized in constructing filtration systems in the food industry, water treatment plants, and wastewater treatment facilities.
What properties does expanded perlite possess?
Expanded perlite is a porous material, meaning its internal structure contains numerous empty spaces where air is permanently trapped. Consequently, it boasts an exceptionally low thermal conductivity coefficient and high acoustic insulation capabilities.
These properties are particularly desirable in modern construction, where there is an increasing emphasis on building energy efficiency. The high insulating ability of perlite ensures excellent thermal comfort both in the autumn-winter and summer periods, thereby reducing heating and cooling expenses for the building.
Furthermore, by utilizing perlite blocks, it is possible to construct walls using single-layer technology, eliminating the need for additional insulation. This significantly reduces construction time and labor costs.
Another advantage of expanded perlite is its high fire resistance. This material is completely non-combustible and holds a fire resistance class of A1. Due to its technical properties, it can withstand even direct exposure to open flames.
For instance, walls built with perlite blocks from SYSTEM 3E can boast a fire-resistance rating of REI 240 + M, ensuring the building's structural integrity for at least 4 hours from the outbreak of a fire. This enables firefighters to more effectively combat house fires, and after the rescue operation, the building should retain its original technical properties.
It is worth emphasizing that expanded perlite is entirely chemically and biologically neutral, making it suitable for individuals dealing with various allergies and respiratory conditions. Perlite blocks also have breathable properties, facilitating the creation of a healthy indoor microclimate. The material itself is non-absorbent, preventing the growth of mold and mildew.