Perlite for Filtration 

Perlite filter aids are lightweight, inert, impart no taste or odor to liquids being filtered, and are virtually insoluble in mineral and organic acids at all temperatures. Solubility in strong alkaline solutions varies depending on temperature and contact time.

Without using a filter aid the solid particles in the liquid will soon accumulate on filtering surfaces and block them.

Expanded perlite provides larger volumes with low bulk density compared to other filter aids. 

Additionally, perlite filter cakes remain porous and do not compact. Filter cakes built up under pressure release easier, potentially reduces manpower and increases productivity. The lower weight may also reduce disposal cost. 

• Density advantage from 20 to 50% over other types of filter aids. 
• Dry Density ranges from 6 to 12 lb/ft3 
• Filter cakes in the range of 15 to 25 lbs/ft3
• 0.2-6 Darcies (Darcy is a common unit of low rate for filter aids)