Tuesday, February 19, 2008

Zeolite

Zeolite Applications Zeolite: The Versatile Mineral Zeolite is a naturally occurring mineral group consisting of over 50 different minerals. Made of a special crystalline structure that is porous but remains rigid in the presence of water, zeolites can be adapted for a variety of uses. Aquaculture Ammonia filtration in fish hatcheries Biofilter media Agriculture Odor control Confined animal environmental control Livestock feed additives Horticulture Nurseries, Greenhouses Floriculture Vegetables/herbs Foliage Tree and shrub transplanting Turf grass soil amendment Reclamation, revegetation, landscaping Silviculture (forestry, tree plantations) Medium for hydroponic growing Household Products Household odor control Pet odor control Industrial Products Absorbents for oil and spills Gas separations Radioactive Waste Site remediation/decontamination Water Treatment Water filtration Heavy metal removal Swimming pools Wastewater Treatment Ammonia removal in municipal sludge/wastewater Heavy metal removal Septic leach fields ZEOLITE is an all natural, multi-use mineral that is far superior to lime in odor control and moisture absorption. it will not dry, crack and burn hooves as lime will. ZEOLITE actually removes ammonia from the air by trapping the ammonia gas in its crystalline structure, thereby keeping the ammonia gas and moisture away from you and your animals. ZEOLITE is a safe non-hazardous, nontoxic, economical solution to a health problem that exists in the environment of horses, cattle, poultry, swine and sheep. ZEOLITE in your animals environment will save you time, labor and money because it is more efficient that any other odor control product you can use, while providing additional health benefits. ZEOLITE costs less than hydrated lime, requires fewer treatments resulting in better performance, less time, less labor and greater economy. Our 100% natural ZEOLITE products contain no additives, no fillers, no clay, no caustic-chemicals and is void of harmful substances. A safe product for all living things. ZEOLITE helps prevent ammonia related health problems, reduces fly infestation, extends bedding life thereby reducing stall maintenance, reduces stall wetness keeping bedding dryer for newbors and animals confined due to illness. ZEOLITE is not a cover up for ammonia odors. it efficiently absorbs and traps the ammonia and related wetness and immediately becomes a slow release nitrogen fertilizer for your yard, garden or fields. It is completely safe in and around the home. INSTRUCTIONS FOR USE: Liberally sprinkle ZEOLITE in the stall or wherever you have an ammonia problem and witness almost immediate relief from odor and wetness. Continue to use during dry season to prevent ammonia buildup in the bedding and in the ground. Discard by using as a natural organic fertilizer wherever needed. Excellent for organic gardening, potting soil and lawns. ZEOLITE FAQ's 1. What are zeolites? Zeolites are three-dimensional, microporous, crystalline solids with well-defined structures that contain aluminum, silicon, and oxygen in their regular framework; cations and water are located in the pores. The silicon and aluminum atoms are tetrahedrally coordinated with each other through shared oxygen atoms. Zeolites are natural minerals that are mined in many parts of the world; most zeolites used commercially are produced synthetically. Zeolites have void space (cavities or channels) that can host cations, water, or other molecules. Because of their regular and reproducible structure, they behave in a predictable fashion. 2. When were zeolites discovered? In 1756, the Swedish mineralogist Axel Fredrick Cronstedt discovered that stilbite, a natural mineral, visibly lost water when heated, and he named the class of materials zeolites from the classical Greek words meaning 'boiling stones.' Zeolites were considered an obscure group of minerals with unique properties for almost 200 years, and Cronstedt was remembered primarily for discovering the element nickel. 3. What are some of the major applications for zeolites? Adsorption - Zeolites are used to adsorb a variety of materials. This includes applications in drying, purification, and separation. They can remove water to very low partial pressures and are very effective desiccants, with a capacity of up to more than 25% of their weight in water. They can remove volatile organic chemicals from air streams, separate isomers and mixtures of gases. Catalysis - Zeolites can be shape-selective catalysts either by transition state selectivity or by exclusion of competing reactants on the basis of molecular diameter. Zeolites can also be acid catalysts and can be used as supports for active metals or reagents. They have also been used as oxidation catalysts. The main industrial application areas are: petroleum refining, synfuels production, and petrochemical production. Synthetic zeolites are the most important catalysts in petrochemical refineries. Ion Exchange - The largest volume use for zeolites is in detergent formulations where they have replaced phosphates as water-softening agents. They do this by exchanging the sodium in the zeolite for the calcium and magnesium present in the water. 4. How do zeolites function as ion exchangers? The framework aluminum and silicon are bound to each other through shared oxygen atoms. The SiO4 units are neutral: Si+4 / 4 O- but the AlO4 results in a net negative charge: Al+3 / 4O- . The net negative charge is balanced by cations that are present during the synthesis. These cations are highly mobile and can be exchanged for other cationic species. 5. How many types of zeolites are there? There are numerous naturally occurring and synthetic zeolites, each with a unique structure. The pore sizes commercially available range from approximately 3 Å to approximately 8 Å. Some of the commercial materials are: A, beta, mordenite, Y, ZSM-5. 6. Are zeolites stable? Many zeolites are thermally stable to over 500 °C. Some are stable in an alkaline environment, and some are stable in acidic media. They are also stable to ionizing radiation and can be used to adsorb radioactive cations. 7. How do zeolites separate molecules? Zeolites can separate molecules based on size, shape, polarity, degree of unsaturation, among others. 8. Are zeolites re-useable? Zeolites can be regenerated using relatively easy methods such as heating to remove adsorbed materials, ion exchanging with sodium to remove cations, or pressure swing to remove adsorbed gases. 9. How can zeolites be modified? Zeolite modification implies an irreversible change, unlike ion exchange or adsorption. There are a number of different ways that zeolites can be modified. The framework of the zeolite can be modified by synthesizing zeolites with metal cations other than aluminum and silicon in the framework. The framework of the zeolites can be modified by dealumination to increase the silica and increase the hydrophobic nature of the zeolite. There are many proprietary methods to modify zeolites that impart unique characteristics to them. 10. In what forms are zeolites available? Zeolites are available as powders or as formed products such as extrudates. Zeolites, like other solids, are safe to handle and are easy to use in a variety of reactors. 11. When were synthetic zeolites first made? During the 1930's, R. Barrer and J. Sameshima did extensive work in zeolite synthesis. In 1948, Richard Barrer first produced a synthetic zeolite that did not have a natural counterpart. At approximately the same time, Milton made the first materials that had no natural counterpart such as zeolite A. 12. Are new zeolites still being discovered? New natural zeolites are still being discovered, and new synthetic zeolites are being invented in many laboratories around the world. 13. What makes zeolites special when compared with other inorganic oxide materials? The combination of many properties, among them: the microporous character of the uniform pore dimensions, the ion exchange properties, the ability to develop internal acidity, the high thermal stability, the high internal surface area. These make zeolites unique among inorganic oxides. 14. What are the health and safety aspects of zeolites? Not all zeolites have been studied, but extensive studies have been done on zeolite A due to its use in consumer products. These studies have demonstrated that type A zeolite is essentially non-toxic via oral, dermal, ocular, and respiratory routes of exposure; type A zeolite was also found to be safe for the environment. Please consult the MSDS for product(s) of interest.

1 comment:

  1. Hi good collection on the side of your blog. keep it up. I hope you will publish good chemistry in your web.

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