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Zeolite exhibited in the Estonian Museum of Natural History. Zeolite is a family of several microporous, crystalline aluminosilicate materials commonly used as commercial adsorbents and catalysts. [1] They mainly consist of silicon, aluminium, oxygen, and have the general formula M n+ 1/n (AlO 2) − (SiO 2) x ･y H 2 O where M n+ 1/n is ...
Clinoptilolite is a natural zeolite composed of a microporous arrangement of silica and alumina tetrahedra. It has the complex formula (Na,K,Ca) 2–3 Al 3 (Al,Si) 2 Si 13 O 36 •12H 2 O. It forms as white, green to reddish tabular monoclinic tectosilicate crystals with a Mohs hardness of 3.5 to 4 and a specific gravity of 2.1 to 2.2.
Pentasil-zeolites are defined by their structure type, and more specifically by their X-ray diffraction patterns. ZSM -5 is the trade name of a pentasil-zeolite. As early as 1967, Argauer and Landolt worked out parameters for the synthesis of pentasilzeolites, particularly those relating to the following molar ratios: OH − /SiO 2 = 0.07–10, SiO 2 /Al 2 O 3 = 5–100, H 2 O/SiO 2 = 1–240. [1]
Under the term zeolites, molecular sieves are used for a wide range of catalytic applications. They catalyze isomerisation , alkylation , and epoxidation , and are used in large scale industrial processes, including hydrocracking and fluid catalytic cracking .
The aluminosilicate framework of LTA-type zeolite (left) and FAU-type zeolite (right). Vertices = Al or Si, oxygen atoms are not shown. Feldspar is a common tectosilicate aluminosilicate mineral made of potassium, sodium, and calcium cations surrounded by a negatively charged network of silicon, aluminium and oxygen atoms.
Faujasite (FAU-type zeolite) is a mineral group in the zeolite family of silicate minerals.The group consists of faujasite-Na, faujasite-Mg and faujasite-Ca. They all share the same basic formula (Na 2,Ca,Mg) 3.5 [Al 7 Si 17 O 48]·32(H 2 O) by varying the amounts of sodium, magnesium and calcium. [1]
Synthetic zeolites have complex structures and examples (with structural formulae) are: Na 12 Al 12 Si 12 O 48 ·27H 2 O, zeolite A (Linde type A sodium form, NaA), used in laundry detergents [4] Na 16 Al 16 Si 32 O 96 ·16H 2 O, Analcime, IUPAC code ANA [4] Na 12 Al 12 Si 12 O 48 ·q H 2 O, Losod [5] Na 384 Al 384 Si 384 O 1536 ·518H 2 O ...
Mordenite is a zeolite mineral with the chemical formula, (Ca, Na 2, K 2)Al 2 Si 10 O 24 ·7H 2 O. and it is one of the six most abundant zeolites and is used commercially. [3] It was first described in 1864 by Henry How. He named it after the small community of Morden, Nova Scotia, Canada, along the Bay of Fundy, where it was first found.