ABSTRACT
292Zeolites are hydrated, microporous crystalline alumina-silicate with three dimensional framework made up of T-O-T (T = Si, Al) bonds with enclosed cages/channels of uniform dimensions. This property enables them to avail as membrane to separate the molecules on the basis of their size; hence they are also known as molecular sieves. Zeolites are widely demanded inorganic resins in the field of water and waste water treatment, credited to its ion exchange, molecular sieving, adsorption, detergent builder, water softening, etc. properties. Many leading detergent manufactures use Zeolite 4A as builder material, which has proven to be a better alternative to phosphatic additives.
Although literature studies reveal the potential applicability of many types of Zeolites, it has been noticed that Zeolite 4A resin is manufactured commercially on a mega scale. In spite of its tremendous potential, the high cost of Zeolite 4A has limited its bulk utility. In this reference, many investigations have been reported on the eco-friendly production of Zeolite 4a resin using waste materials such as flash, rice husk ash, composite ash generated from coal and biomass co-firing, aluminum waste, ceramic and clay minerals, etc. The current paper accounts the efforts attempted by researchers towards the manufacture of Zeolite 4A with economic consideration along with delineation applications.
