Midwest Perlite, your source for expanded perlite.
Origin and Characteristics of Perlite.
Perlite is not a trade name but a generic term for naturally occurring siliceous volcanic rock. The distinguishing feature which sets perlite apart from other volcanic glasses is that when it is heated to a suitable point in its softening range, it expands from four to twenty times its original volume. This expansion is dues to the presence of two to six percent combined water in the crude perlite rock. When quickly heated to above 871°C (1600°F), the crude rock pops in a manner similar to popcorn as the combined water vaporizes and creates countless tiny bubbles which account for the amazing light weight and other exceptional physical properties of expanded perlite. It does not create by-products during processing; only the physical form is altered.
This expansion process also creates one of the perlite’s most distinguishing characteristics: its white color. While the crude rock may range from transparent light gray to glossy black, the color of expanded perlite ranges from snowy white to grayish white. Expanded perlite can be manufactured to weigh as little as (32kg/m3) making it adaptable for numerous applications in construction, industrial, chemical and horticultural. The particle size of expanded perlite is an important factor how it works in a given application. Other factors such as physical structure and density can also be critical in certain applications.
Perlite is a natural, versatile and efficient mineral that is abundant, lightweight, insulating, and non-flammable. It’s unique characteristics make it an excellent choice for such diverse applications. Some typical applications are garden & soil amendments, insulating concrete, masonry loose fill, and filter aid. Products are made from all particle sizes and densities making perlite, “no waste” industrial mineral.