摘要:
Preparation of porous crystalline silicates having the structure of ZSM-5 and a mesitylene sorption capacity of at least 3.0 weight percent from a non-organic reaction mixture having at least about 35 weight percent solids content and a OH⁻/SiO₂ molar ratio of at least about 0.11.
摘要:
A novel family of layered clays, called lithiated clays is disclosed. The novel layered clays are characterised by the replaceable hydrogens of the hydroxyl groups within the structure of a layered clay being replaced by lithium. A method of manufacturing the lithiated clays is disclosed together with their use as catalysts.
摘要:
Zeolite L containing caesium is prepared by a process in which said zeolite L is crystallised from a synthesis mixture with a molar composition (expressed as oxides) of:
K₂O/SiO₂ 0.15 to 0.40 K₂O/Cs₂O 3 to 10 H₂O/K₂O 40 to 100 and SiO₂/Al₂O₃ 7 to 13
and containing 0.5 to 15 ppm (by weight) of divalent metal cations, e.g. Mg ions. The zeolite L can form part of a dehydrocyclisation and/or isomerisation catalyst.
摘要翻译:含沸石L的铯是用一种方法制备的,其中所说的沸石L由摩尔组成(用氧化物表示):K 2 O / SiO 2 0.15-0.40 K 2 O / Cs 2 O 3 -10H 2 O / K 2 O 40-100的合成混合物结晶, SiO 2 / Al 2 O 3 7-13,含有0.5-15ppm(按重量计)的二价金属阳离子, 镁离子。 沸石L可以形成脱氢环化和/或异构化催化剂的一部分。
摘要:
A layered silicate or metallosilicate has the following X-ray diffraction pattern : In the as-synthesized form, it has the formula, expressed in terms of mole ratios of oxides in the anhydrous state, (3.5 to 6.0) RO · (0 to 1) M 2/m O · Al₂O₃ · (100 to 5000) SiO₂ in which R is wherein n is 4 or 5; and in which M is alkali metal cation and m is 1. The layered silicate or metallosilicate can be converted to a pillared material in which adjacent layers are separated by metal oxide pillars.
摘要:
A synthetic mordenite molded body is prepared by a process wherein a starting mixture comprising as the main components a silica source, an alumina source, an alkali source and water is molded into a starting molded body, the molded body is calcined and the calcined molded body is heated in an aqueous solution of sodium silicate. The starting mixture has incorporated therein a mordenite seed crystal powder. When the molded body is calcined, the temperature is elevated by heating to a calcination temperature not lower than 400°C at an average rate of at least 10°C/min and calcination is conducted at the calcination temperature within 2 hours. When the calcined molded body is crystallized, an aqueous solution of sodium silicate having an SiO 2 concentration of 7 to 25% by weight, an Na 2 O concentration of 2 to 8% by weight and an SiO 2 /Na 2 O molar ratio of from 0.9 to 4.0 is used as the aqueous solution of sodium silicate.
摘要:
Crystalline zeolites and zeolitic materials are prepared by crystallisation from an aqueous mixture comprising a source of silica, optionally a source of alumina, and an ion-exchange resin preferably an anion-exchange resin. In a preferred form of the invention the anion-exchange resin is in the hydroxide form and the reaction mixture also contains a quaternary ammonium compound.
摘要:
A continuous process is described for manufacturing a wide variety of zeolites having selected crystal sizes and other desired characteristics. Selected raw materials are fed to a precursor tank 11 of relatively large capacity, wherein the resultant zeolite precursor slurry is held at temperatures of up to 180°F (82°C) for 4-16 hours, with high shear agitation, as an induction period. The slurry is sent to a plurality of crystallization tanks 14, 18 before it possesses a total solids content exceeding 10% by weight and a crystalline content exceeding 15% by weight of the total solids content. The crystallization tanks are operated in two stages, the first crystallizing stage 14 being held at a temperature of 180-250°F (82-121°C) for 2-72 hours, and the second crystallizing stage 18 being held at a temperature greater than 250°F (121°C) for 2-16 hours.
摘要:
Verfahren zur Herstellung von kristallinen zeolithischen Alumosilicaten mit einem Si/AI-Atomverhältnis von ≥ 10 durch hydrothermale Kristallisation aus einem Reaktionsansatz, der in wäßrig-alkalischem Medium SiO 2 und Al 2 O 3 bzw. Derivate dieser Verbindungen, Kristallisationsbeschleuniger und gegebenenfalls quaternäre Ammoniumverbindungen enthält. Dem Reaktionsgemisch wird als Kristallisationsbeschleuniger ein gealtertes, aber noch nicht kristallines, röntgenamorphes Alumosilicat-Keimbildungsgel zugesetzt.
摘要:
La présente invention a trait à un procédé d'obtention d'une zéolite par alimentation en continu d'une solution aqueuse de silicate de sodium (2) et d'une solution aqueuse d'aluminate de sodium (1). Ce procédé se caractérise par le fait que les solutions d'aluminate (1) et de silicate (2) sont alimentées dans un réacteur (3) non agité, de manière que le temps de mélange soit inférieur au temps de gélification. On peut également réaliser un transfert de chaleur moyen d'un éjecteur vapeur (4), disposé en sortie du réacteur tubulaire (3). Ce procédé s'applique, en particulier, à la synthèse des zéolites A.