A very special kind of rock, zeolites hold water inside it. The term refers numerous different minerals that have many interesting uses, including water softeners, animal food, industrial catalysts and more.
What are Zeolites?
Widely used as commercial adsorbents & catalysts, Zeolites are hydrated aluminosilicate minerals. They are made from interconnected tetrahedrons of alumina (AlO4) and silica (SiO4). In simple, they are solids with a moderately open, 3-dimensional crystal structure made-up from the elements aluminum, silicon & oxygen, with alkali / alkaline-Earth metals (such as potassium, sodium and magnesium) plus molecules of water trapped in the openings between them. Zeolites create with many different crystalline structures, having large open pores / cavities in a regular organization and approximately the same size as small molecules.
About 40 naturally occurring zeolites are there, forming in volcanic as well as sedimentary rocks. As per the US Geological Survey, the most commonly mined varieties include chabazite, mordenite and clinoptilolite. Lots of artificial and synthetic zeolites (approximately 150) have been designed for particular purposes; the best-known of which are zeolite A (used as a laundry detergent), zeolites X and Y (two different forms of faujasites, used for catalytic cracking), and petroleum catalyst ZSM-5 (a proprietary name for pentasil-zeolite).
What specific properties do zeolites have?
Zeolites are highly stable solids that withstand the kinds of environmental conditions that are challenging for many other materials. With relatively high melting points (over 1000°C), they resist high temperatures. Also, they withstand high pressures, and don't dissolve in water or different inorganic solvents. They don't oxidize in the air as well. Zeolites are not considered to cause health problems. Based on naturally occurring minerals, they're not harmful for the environment.
The very interesting thing about zeolites is their open, cage-like structure, and the way they trap other molecules inside. Zeolites have fixed size regular openings in them, which allow small molecules pass straight through, and trap larger ones. Natural zeolites occur in random forms and mixed sizes, and the synthetic zeolites are manufactured in precise, uniform sizes to suit a specific application.
Usages of zeolites
Everyday uses – water filters, water softeners, laundry & dishwasher detergents. Odor control, pet litter, and other effective utilization in our homes. Commercial water purification, softening, and other applications. The many other utilities for zeolites include: soil-conditioners, concrete production, dietary supplements, animal food, and more.
What are zeolites catalysts?
The zeolites are also important as catalysts in pharmaceutical (drug) production, and in the petrochemical manufacture, where they are used in catalytic crackers to break big hydrocarbon molecules into gasoline, kerosene, diesel, waxes and other petroleum byproducts. Once again, the porous structure of zeolites proves to be essential. The numerous pores in zeolites open structure are similar to millions of tiny test tubes, where molecules / atoms become trapped and chemical reactions promptly take place. Like all catalysts, the zeolites are reusable time and again.