The reservoirs and potentials of perlite in Iran (A case study on perlite reservoirs of middle cenozoic volcanic zone of Mianeh in East Azerbaijan province)

Abstract

Perlite is a type of volcanic stone with acidic composition which forms in water environment. It has a glass-like texture in which spherical shapes are formed (i.e. water content of 3 to 5 percent). Heating the perlite (700 to 1200 °C) contributes to its loss of molecular water content and increase of volume up to 10 times the extent of which is dependent upon containing molecular content. Perlite is widely used in diverse industries due to its low density, low conductivity, neutrality, non-combustion, low hardness, good brightness, absorption, and proper strength. In most of the applications, perlite is used in expanded form but in some situations, the raw perlite is also used based on its physicochemical properties in casting industry, abrasives, and as sources of silica. Of the most significant applications of processed perlite, one could point to construction materials and prefabricated parts, soil fertilizer and livestock feed in agriculture, fillers in some industrial applications, and thermal insulations in chemical industries for production and refining food and medicinal materials. Turkey, Greece and United States have respectively the highest levels of perlite reservoirs in the world. A major proportion of perlite reservoirs in Iran are found in Cenozoic volcanic areas. Most of the discovered perlite reservoirs in Iran are located at the north of Mianeh Zone. This zone is located near Sahand and Ghar E-Chaman-TorkamanchayZone which leads to eastern sections of Bazghosh in northwest-southeast direction. The ShirinBalagh, Dash Atan, Sari Ghomish, Ajmi, Abic, Ashlagh Chai, etc. are located in this zone.