Zeolite

The micro-porous molecular structure of a zeolite, ZSM-5

Zeolites (Greek, zein, "to boil"; lithos, "a stone") are minerals that have a micro-porous structure. The term was originally coined in the 18th century by a Swedish mineralogist named Axel Fredrik Cronstedt who observed, upon rapidly heating a natural mineral, that the stones began to dance about as the water evaporated. Using the Greek words which mean "stone that boils," he called this material zeolite. Zeolite. ... Zeolite. ... Image File history File links Download high-resolution version (1100x1221, 969 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Zeolite User:Benjah-bmm27/Gallery ... Image File history File links Download high-resolution version (1100x1221, 969 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Zeolite User:Benjah-bmm27/Gallery ... A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition, a highly ordered atomic structure and specific physical properties. ... (17th century - 18th century - 19th century - more centuries) As a means of recording the passage of time, the 18th century refers to the century that lasted from 1701 through 1800. ... Mineralogy is an earth science that involves the chemistry, crystal structure, and physical (including optical) properties of minerals. ... Baron Axel Fredrik Cronstedt (1722 – 1765) was a Swedish chemist who discovered nickel in 1751. ...

More than 1500 zeolite types have been synthesized and 48 naturally occurring zeolites are known. They are basically hydrated alumino-silicate minerals with an "open" structure that can accommodate a wide variety of cations, such as Na⁺, K⁺, Ca²⁺, Mg²⁺ and others. These positive ions are rather loosely held and can readily be exchanged for others in a contact solution. Some of the more common mineral zeolites are: analcime, chabazite, heulandite, natrolite, phillipsite, and stilbite. An example mineral formula is: Na₂Al₂Si₃O₁₀-2H₂O, the formula for natrolite. The silicate minerals make up the largest and most important class of rock-forming minerals. ... An ion is an atom or group of atoms with a net electric charge. ... Analcite or analcime (from the Greek analkimos - weak) is a white, grey, or colourless tectosilicate mineral. ... Categories: Silicate minerals | Mineral stubs ... Heulandite - Wikipedia /**/ @import /skins-1. ... Natrolite is a mineral species belonging to the zeolite group. ... Phillipsite is a mineral of the zeolite group; a hydrated potassium, calcium and aluminium silicate, approximating to (Ca,Na2,K2)3Al6Si10O32. ... Stilbite is a mineral of the zeolite group consisting of hydrated calcium aluminium silicate, NaCa2Al5Si13O36*14H2O. Stilbite from Kiui Island, Alaska, USA Usually a small proportion of the calcium is replaced by sodium. ...

Natural zeolites form where volcanic rocks and ash layers react with alkaline groundwater. Zeolites also crystallized in post-depositional environments over periods ranging from thousands to millions of years in shallow marine basins. Naturally occurring zeolites are rarely pure and are contaminated to varying degrees by other minerals, metals, quartz or other zeolites. For this reason, naturally occurring zeolites are excluded from many important commercial applications where uniformity and purity are essential. This article is about volcanoes in geology. ... Ash plume from Mt Cleveland, a stratovolcano Diamond Head, a well-known backdrop to Waikiki in Hawaii, is an ash cone that solidified into tuff Volcanic ash consists of very fine rock and mineral particles less than 2 mm in diameter that are ejected from a volcanic vent. ... The common (Arrhenius) definition of a base is a chemical compound that either donates hydroxide ions or absorbs hydrogen ions when dissolved in water. ...

Zeolites are the aluminosilicate members of the family of microporous solids known as "molecular sieves". The term molecular sieve refers to a particular property of these materials, i.e. the ability to selectively sort molecules based primarily on a size exclusion process. This is due to a very regular pore structure of molecular dimensions. The maximum size of the molecular or ionic species that can enter the pores of a zeolite is controlled by the diameters of the tunnels. These are conventionally defined by the ring size of the aperture, where, for example, the term "8ring" refers to a closed loop that is built from 8 tetrahedrally coordinated silicon (or aluminium) atoms and 8 oxygen atoms. These rings are not always perfectly flat and symmetrical due to a variety of effects, including strain induced by the bonding between units that are needed to produce the overall structure, or coordination of some of the oxygen atoms of the rings to cations within the structure. Therefore, the pore openings for all rings of one size are not identical. A molecular sieve is a material containing tiny pores of a precise and uniform size that is used as an adsorbent for gases and liquids. ...

Sources

Conventional open pit mining techniques are used to mine natural zeolites. The overburden is removed to allow access to the ore. The ore may be blasted or stripped for processing by using tractors equipped with ripper blades and front-end loaders. In processing, the ore is crushed, dried, and milled. The milled ore may be air-classified as to particle size and shipped in bags or bulk. The crushed product may be screened to remove fine material when a granular product is required, and some pelletized products are produced from fine material. Producers also may modify the properties of the zeolite or blend their zeolite products with other materials before sale to enhance their performance. The El Chino mine located near Silver City, New Mexico is an open-pit copper mine Open-pit mining refers to a method of extracting rock or minerals from the earth by their removal from an open pit or borrow. ...

Currently, the world’s annual production of natural zeolite is about 4 million tons. Of this quantity, 2.6 million tons are shipped to Chinese markets to be used in the concrete industry. Eastern Europe, Western Europe, Australia, and Asia are world leaders in supplying the world’s demand for natural zeolite. By comparison, only 57,400 metric tons (source: U.S. Geological Survey, 2004) of zeolite (only 1% of the world’s current production) is produced in North America; only recently has North America realized the potential for current and future markets. Concrete being poured, raked and vibrated into place in residential construction in Toronto, Ontario, Canada. ...

There are several types of synthetic zeolites that form by a process of slow crystallization of a silica-alumina gel in the presence of alkalis and organic templates. One of the important process to carry out zeolite synthesis is sol-gel processing. The product properties depend on reaction mixture composition, pH of the system, operating temperature, pre-reaction 'seeding' time, reaction time as well as the templates used. In sol-gel process, other elements (metals, metal oxides) can be easily incorporated. The silicalite sol formed by the hydrothermal method is very stable. Also the ease of scaling up this process makes it a favorite route for zeolite synthesis. Quartz crystal Synthetic bismuth hopper crystal Insulin crystals Gallium, a metal that easily forms large single crystals A huge monocrystal of potassium dihydrogen phosphate grown from solution by Saint-Gobain for the megajoule laser of CEA. In chemistry and mineralogy, a crystal is a solid in which the constituent atoms... The chemical compound silicon dioxide, also known as silica, is the oxide of silicon, chemical formula SiO2. ... Aluminium oxide (or aluminum oxide) (Al2O3) is a chemical compound of aluminium and oxygen. ... Sol gel is a colloidal suspension of silicon dioxide that is gelled to form a solid. ... Hydrothermal circulation in the oceans is the passage of the water through mid-ocean Ridge (MOR) systems. ...

Synthetic zeolites hold some key advantages over their natural analogs. The synthetics can, of course, be manufactured in a uniform, phase-pure state. It is also possible to manufacture desirable zeolite structures which do not appear in nature. Zeolite A is a well-known example. Since the principal raw materials used to manufacture zeolites are silica and alumina, which are among the most abundant mineral components on earth, the potential to supply zeolites is virtually unlimited. Finally, zeolite manufacturing processes engineered by man require significantly less time than the 50 to 50,000 years prescribed by nature. Disadvantages include the inability to create crystals with dimensions of a comparable size to their natural counterparts.

Uses

Commercial and Domestic

Zeolites are widely used as ion-exchange beds in domestic and commercial water purification, softening, and other applications. In chemistry, zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through), as traps for molecules so they can be analyzed. Control room and schematics of the water purification plant to Bret lake. ... In science, a molecule is a group of atoms in a definite arrangement held together by chemical bonds. ...

Zeolites have the potential of providing precise and specific separation of gases including the removal of H₂O, CO₂ and SO₂ from low-grade natural gas streams. Other separations include: noble gases, N₂, freon and formaldehyde. However at present, the true potential to improve the handling of such gases in this manner remains unknown. Natural gas is a gaseous fossil fuel consisting primarily of methane but including significant quantities of ethane, butane, propane, carbon dioxide, nitrogen, helium and hydrogen sulfide. ... The noble gases are a chemical series. ... Freon is a trade name for a group of chlorofluorocarbons used primarily as a refrigerant. ... The chemical compound formaldehyde (also known as methanal) is a gas with a pungent smell. ...

Petrochemical industry

Synthetic zeolites are widely used as catalysts in the petrochemical industry, for instance in fluid catalytic cracking and hydro-cracking. Zeolites confine molecules in small spaces, which causes changes in their structure and reactivity. The hydrogen form of zeolites (prepared by ion-exchange) are powerful solid-state acids, and can facilitate a host of acid-catalyzed reactions, such as isomerisation, alkylation, and cracking. Catalytic cracking uses a furnace and reactor. First crude oil distillation fractions are heated in the furnace and passed to the reactor. In the reactor the crude meets with a catalyst such as zeolite. It goes through this step three times, each time getting cooler. Finally it reaches a step know as separator. The separator collects recycled hydrogen. Then it goes through a fractionator and becomes the final item. It has been suggested that this article or section be merged into Catalysis. ... Factory of Shukhov cracking process, Baku, USSR, 1934 In petroleum geology and chemistry, cracking is the process whereby complex organic molecules such as kerogens or heavy hydrocarbons are broken down into simpler molecules (e. ... Ion exchange is defined as an exchange of ions between two electrolytes. ... Acidity redirects here. ... In chemistry, isomerization is the transformation of a molecule into a different isomer. ... Alkylation is the transfer of an alkyl group from one molecule to another. ...

Nuclear Industry

Zeolites have uses in advanced reprocessing methods, where their micro-porous ability to capture some ions while allowing others to pass freely allow many fission products to be efficiently removed from nuclear waste and permanently trapped. Equally important are the mineral properties of zeolites. Their alumino-silicate construction is extremely durable and resistant to radiation even in porous form. Additionally, once they are loaded with trapped fission products, the zeolite-waste combination can be hot pressed into an extremely durable ceramic form, closing the pores and trapping the waste in a solid stone block. This is a waste form factor that greatly reduces its hazard compared to conventional reprocessing systems. [1]

Agriculture

In agriculture, clinoptilolite (a naturally occurring zeolite) is used as a soil treatment. It provides a source of slowly released potassium. If previously loaded with ammonium, the zeolite can serve a similar function in the slow release of nitrogen. Cuban studies in the emerging field of "zeoponics" suggest that some crops may be grown in 100% zeolite or zeolite mixtures in which the zeolite is previously loaded or coated with fertilizer and micronutrients. Zeolites can also act as water moderators, in which they will absorb up to 55% of their weight in water and slowly release it under plant demand. This property can prevent root rot and moderate drought cycles. Clinoptilolite is a zeolite. ... General Name, Symbol, Number potassium, K, 19 Chemical series alkali metals Group, Period, Block 1, 4, s Appearance silvery white Standard atomic weight 39. ... A ball-and-stick model of the ammonium cation Fumes from hydrochloric acid and ammonia forming a white cloud of ammonium chloride Ammonium is also an old name for the Siwa Oasis in western Egypt. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless gas Standard atomic weight 14. ... Spreading manure, an organic fertilizer Fertilizers (also spelled fertilisers) are compounds given to plants to promote growth; they are usually applied either via the soil, for uptake by plant roots, or by foliar feeding, for uptake through leaves. ... Micronutrients for plants: There are about eight nutrients essential to plant growth and health that are only present in very small quantities. ...

A potting soil with 12% clinoptilolite was shown to harvest morning dew and return it to the plant roots for reuse. The same bed was able to grow a Jerico strain of leaf lettuce in a sub tropical climate without external water and daytime temperatures exceeding 85 °F. This produce did not bolt and went full term before setting seeds. It also has been shown that certain zeolites can reduce nitrates and nitrites to more plant usable free nitrogen by ion exchange.^{[citation needed]}

Animal Welfare

In Concentrated Animal Growing facilities, the addition of as little as 1% of a very low sodium clinoptiloite was shown to improve feed conversion, reduce airborne ammonia up to 80%, act as a mycotoxin binder and improve bone density. see US Patents 4,917,045 and 6,284,232

Medical

Zeolite-based oxygen generation systems are widely used to produce medical grade oxygen. The zeolite is used as a molecular sieve to create purified oxygen from air, in a process involving the absorption of undesired gases and other atmospheric components, leaving highly purified oxygen and up to 5% argon.

Heating and refrigeration

Zeolites can be used as solar thermal collectors and for adsorption refrigeration. In these applications, their high heat of adsorption and ability to hydrate and dehydrate while maintaining structural stability is exploited. This hygroscopic property coupled with an inherent exothermic reaction when transitioning from a dehydrated to a hydrated form (heat adsorption), make natural zeolites effective in the storage of solar and waste heat energy. A Solar thermal collector absorbs sunlight to provide heat. ... The absorption refrigerator is a refrigerator that utilizes a heat source to provide the energy needed to drive the cooling system rather than being dependent on electricity to run a compressor. ... A hygroscopic substance is a substance that absorbs water readily from its surroundings. ... In thermodynamics, the word exothermic describes a process or reaction that releases energy in the form of heat. ...

Detergents

The largest outlet for synthetic zeolite is the global laundry detergent market. This amounted to 1.44 million metric tons per year of anhydrous zeolite A in 1992. Laundry detergents are just one of many possible uses for detergents Detergent is a compound, or a mixture of compounds, intended to assist cleaning. ...

Construction

Synthetic zeolite is also being used as an additive in the production process of warm mix asphalt concrete. The development of this application started in Europe (Germany) in the 1990s. It helps by decreasing the temperature level during manufacture and laying of asphalt concrete, resulting in lower consumption of fossil fuels, thus releasing less carbon dioxide, aerosols and vapours. When added to Portland Cement as a Pozzolan, it can reduce chloride permeability and improve workability. It reduces weight and helps moderate water content while allowing for slower drying which improves break strength.^{[citation needed]} As shown in this cross-section, many older roadways are smoothed by applying a thin layer of asphalt concrete to the existing portland cement concrete. ... Carbon dioxide is a chemical compound composed of one carbon and two oxygen atoms, and is in a gaseous state in the atmosphere of the Earth. ...

Gemstones

Thomsonites have been collected as gemstones from a series of lava flows along Lake Superior in Minnesota and to a lesser degree in Michigan, U.S.A.. Thomsonite nodules from these areas have eroded from basalt lava flows and are collected on beaches and by scuba divers in Lake Superior. Zeolite Zeolites (Greek, zein,to boil;lithos,a stone) are minerals that have a porous structure. ... A selection of gemstone pebbles made by tumbling rough rock with abrasive grit, in a rotating drum. ... Look up lava, Aa, pahoehoe in Wiktionary, the free dictionary. ... Lake Superior, bounded by Ontario, Canada and Minnesota, USA, to the north and Wisconsin and Michigan, USA, to the south, is the largest of North Americas Great Lakes. ... Capital Saint Paul Largest city Minneapolis Area  Ranked 12th  - Total 87,014 sq mi (225,365 km²)  - Width 250 miles (400 km)  - Length 400 miles (645 km)  - % water 8. ... Official language(s) None (English, de-facto) Capital Lansing Largest city Detroit Area  Ranked 11th  - Total 97,990 sq mi (253,793 km²)  - Width 239 miles (385 km)  - Length 491 miles (790 km)  - % water 41. ... Severe soil erosion in a wheat field near Washington State University, USA. For erosion as an operation of Mathematical morphology, see Erosion (morphology) Erosion is displacement of solids (soil, mud, rock and other particles) by the agents of ocean currents, wind, water, or ice by downward or down-slope movement... Basalt Basalt (IPA: ) is a common gray to black extrusive volcanic rock. ...

These thomsonite nodules have concentric rings in combinations of colors, black, white, orange, pink, red and many shades of green. Some nodules have copper as inclusions and rarely will be found with copper "eyes". When polished by a lapidary the thomsonites sometimes display chatoyancy.^[1] General Name, Symbol, Number copper, Cu, 29 Chemical series transition metals Group, Period, Block 11, 4, d Appearance metallic pinkish red Standard atomic weight 63. ... A lapidary (the word means concerned with stones) is an artisan who practices the craft of working, forming and finishing stone, mineral, gemstones, and other suitably durable materials (amber, shell, jet, pearl, copal, coral, horn and bone, glass and other synthetics) into functional and/or decorative, even wearable, items (e. ... Tiger eye In gemology, chatoyancy (or chatoyance) is an optical reflectance effect seen in certain gemstones. ...

Aquarium keeping

Zeolites are marketed by pet stores for use as a filter additive in aquariums. In aquariums, zeolites can be used to absorb ammonia and other nitrogenous compounds. However, due to the high affinity of some zeolites for calcium, they may be less effective in hard water and may deplete calcium. Zeolite filtration is used in some marine aquaria to keep nutrient concentrations low for the benefit of corals adapted to nutrient-depleted waters. Aquarium is also the name of the Russian band, which is also spelled Akvarium A 335,000 gallon (1. ... Ammonia is a compound with the formula NH3. ...

Zeolite mineral species

The Zeolite family includes

Analcite or analcime (from the Greek analkimos - weak) is a white, grey, or colourless tectosilicate mineral. ... Brewsterite is the name of a series of tecto-silicate minerals of the zeolite group. ... Categories: Silicate minerals | Mineral stubs ... Clinoptilolite is a zeolite. ... The ferrierite group of zeolite minerals consists of three very similar varieties: ferrierite-Mg, ferrierite-Na, and ferrierite-K, based on the dominant cation. ... Gismondine is a mineral with the chemical formula CaAl2Si2O8·4(H2O). ... Gmelinite is one of the rarer of the zeolite minerals being a hydrated silicate of calcium, aluminium and either sodium or potassium with formula: (Na2,Ca)Al2Si4O12·6H2O. It forms striking crystals, shallow, six sided double pyramids, either white, pink, yellow or reddish. ... Harmotome is a mineral, one of the rarer zeolites; a hydrated barium silicate with formula: (Ba0. ... Heulandite - Wikipedia /**/ @import /skins-1. ... Laumonite is a mineral, one of the Zeolite Group. ... Mesolite is a mineral, formula Na2Ca2(Al2Si3O10)3. ... Mordenite (chemically, hydrated calcium sodium potassium aluminum silicate) is a rare zeolite mineral. ... Natrolite is a mineral species belonging to the zeolite group. ... Phillipsite is a mineral of the zeolite group; a hydrated potassium, calcium and aluminium silicate, approximating to (Ca,Na2,K2)3Al6Si10O32. ... Pollucite is a mineral, one of the Zeolite group pf minerals. ... A sample of scolecite Scolecite is a tectosilicate mineral belonging to the zeolite group; a hydrated calcium silicate, CaAl2Si3O10·3H2O. Its name came from the Greek word, skolec = worm because of its reaction to the blowpipe flame. ... Stilbite is a mineral of the zeolite group consisting of hydrated calcium aluminium silicate, NaCa2Al5Si13O36*14H2O. Stilbite from Kiui Island, Alaska, USA Usually a small proportion of the calcium is replaced by sodium. ... Zeolite Zeolites (Greek, zein,to boil;lithos,a stone) are minerals that have a porous structure. ...

References

1. ^ http://www.cst.cmich.edu/users/dietr1rv/thomsonite.htm R. V. Dietrich, 2006, Thomsonite

• Zeolites in Sedimentary Rocks. Ch. in United States Mineral Resources, Professional Paper 820, 1973.
• Natural and Synthetic Zeolites. U.S. Bureau of Mines Information Circular 9140, 1987.

• La roca magica: Uses of natural zeolites in agriculture and industry

Frederick A. Mumpton. National Academy of Sciences Vol. 96, Issue 7, 3463-3470, March 30, 1999 Abstract

See also

List of minerals Gem animals. ...

External links

• European Zeolites Producers Association
• Database of Zeolite Structures
• The Synthesis Commission of the International Zeolite Association
• British Zeolite Association
• U.S. Geological Survey, References on Zeolites