Perlite in construction
Perlite is a unique volcanic glass widely utilized in the construction industry due to its lightweight, insulating, and fire-resistant properties. Formed from rapidly cooled lava, perlite undergoes a significant expansion when heated, increasing its volume up to twenty times and creating a foamy material that is easy to work with. Predominantly mined in the western United States, particularly in states like New Mexico, Nevada, and California, perlite is also sourced from countries such as Greece, Hungary, and Turkey.
In construction, expanded perlite is primarily mixed with cement or gypsum to create concrete and plaster. While it may not be as strong or cost-effective as traditional aggregates like sand and gravel, its advantages include improved thermal and sound insulation, making it a valuable addition to various building materials. Additionally, perlite serves multiple purposes beyond construction, including its use in ceramics, filters, and as a filler in various products. This versatility and beneficial physical properties have led to its increasing adoption in modern building practices.
Perlite in construction
Where Found
Perlite is mined primarily in the western United States, especially in New Mexico, Nevada, California, Arizona, Colorado, Idaho, and Utah. It is also found in Hungary, Greece, Japan, Mexico, Turkey, and the former Soviet states.
Primary Uses
Perlite is used mostly in construction, where it is mixed with substances such as cement or gypsum to form concrete or plaster. Perlite is also used in insulation, ceramics, filters, and fillers.
Technical Definition
Also known as pearlstone, perlite is a naturally occurring glass of volcanic origin. Like other volcanic glasses, perlite consists mostly of silicon dioxide, which makes up about 70 percent of its chemical content. About 10 to 15 percent is aluminum oxide. Perlite also contains small amounts of various other oxides, along with about 3 to 5 percent water. The water content of perlite causes it to expand up to twenty times its normal volume when heated, resulting in a light, foamy material. Other volcanic glasses that do not contain perlite’s distinctive fracture pattern are often called “perlite” if they contain enough water to expand in a similar fashion.
Description, Distribution, and Forms
Perlite is a form of natural glass. Natural glasses form when molten from volcanoes is cooled rapidly. The lava hardens too quickly to allow crystals to grow, resulting in a substance with a glassy rather than a stony texture. Perlite is distinguished from other forms of natural glass in that it contains many tiny curved fractures structured like the layers of an onion. These fractures may be microscopic or may be visible to the naked eye. Because of these fractures, perlite breaks apart into small, round, pearl-like particles. Perlite has a waxy or pearly luster and may be gray, green, brown, blue, or red. The term “perlite” is also more loosely used to mean any natural glass that expands into a light, frothy material when heated.
Most of the world’s perlite is found in the western half of the United States. New Mexico supplies about three-quarters of the nation’s perlite. Because underground deposits of natural glass slowly crystallize into stony substances over time, perlite is almost always found at or near the Earth’s surface. Greece, Hungary, Japan, Mexico, and Turkey are also major producers of perlite.
History
Though perlite has been known as a volcanic for more than two thousand years, it was not used industrially until the twentieth century. By the 1970s, it was a common product used in the horticultural industry.
Obtaining Perlite
Because perlite is found near the surface, it is mined using the open-pit method. It is then crushed to the desired particle size and transported to a processing center, where it is heated to expand it.
Uses of Perlite
The expanded perlite is used as an aggregate; that is, it is mixed with other substances such as gypsum to form plaster or cement to form concrete. Although perlite is not as strong or inexpensive as other aggregates such as sand or gravel, it has the advantages of being light, fire-resistant, and a good insulator of heat and sound. Perlite is also used as insulation or filler and in and filters.
Bibliography
Nicolina, Dorina, et al. "Perlite Concrete: A Review." IOP Conference Series Materials Science and Engineering, June 2023, DOI:10.1088/1757-899X/1283/1/012003. Accessed 29 Dec. 2024.
"Perlite: The Most Sustainable Insulation Solution for Buildings." Perlite Institute, www.perlite.org/perlite-the-most-sustainable-insulation-solution-for-buildings/. Accessed 29 Dec. 2024.
"What Does Perlite Do in Potting Soil?" Supreme Perlite, 16 Apr. 2024, www.supremeperlite.com/what-does-perlite-do-potting-soil/. Accessed 28 Dec. 2024.