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PERLITE
Perlite is an expanded silaceous rock (silica). It is usually manufactured by milling to a desired particle size, adding 1-3% water and then rapidly heating to about 1600 deg. F, where it pops similar to popcorn. In fact, the particles are similar to popcorn when viewed under a microscope. The result is a low density powder (2-8 lbs/cu.ft.) with complex shapes and crevices that can be used for some filtration processes. Fundamentally, perlite performs the solid/liquid separation process differently than DE. The individual perlite particles themselves possess few pore structures as opposed to DE, which by nature of its intricate channel and throat pore structure actually traps and retains particulate matter. Perlite generally traps contaminants in the interstitial spaces between media particles forming a matrix. The material is considered non-hazardous except as a nuisance dust.