Toyo Soda Manufacturing Co., Ltd.

Hiroshi Miyazaki

Junji Arika

Isao Miyanohara

Keiji Itabashi

Michiyuki Aimoto

Hideo Kawamura

Kazushige Igawa

Masashi Harada

Shinichi Hashimoto

A synthetic faujasite molded body having high purity and high crystallinity is prepared with a good reproducibility by a process wherein a structure-inducing substance is incorporated in a starting material mixture comprising as main components a silica source, an alumina source, an alkali source and water; the mixture is kneaded and molded into a desired shape; and the molded body is heated in an aqueous solution of an alkali metal silicate or hydroxide. The structure-inducing material has a composition defined by the following oxide molar ratios:

Process for preparation of synthetic faujasite molded body

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.degree. C. at an average rate of at least 10.degree. C./min and calcination is conducted at the calcination temperature within a time period of 2 hours. When the calcined molded body is crystallized, an aqueous solution of sodium silicate having an SiO.sub.2 concentration of 7 to 25% by weight, an Na.sub.2 O concentration of 2 to 8% by weight and an SiO.sub.2 /Na.sub.2 O molar ratio of from 0.9 to 4.0 is used as the aqueous solution of sodium silicate.

Process for preparation of synthetic mordenite molded body

A faujasite zeolite of a high purity and a desired silica/alumina ratio is prepared by crystallizing at an elevated temperature a reaction mixture comprising a silica source, an alumina source, and an alkali metal source, wherein a transparent faujasite germ solution obtained by mixing and aging aqueous alkali metal silicate solution, an aqueous alkali metal aluminate solution and an aqueous alkali metal hydroxide solution is made present in the reaction mixture. The faujasite germ solution has an oxide molar composition represented by the following molar ratios:

Process for preparation of faujasite zeolite

A mordenite type zeolite having a high purity and a high SiO.sub.2 /Al.sub.2 O.sub.3 molar ratio is prepared without using an organic or inorganic mineralizer, by a process wherein a homogeneous aluminosilicate containing 3 to 14% by weight, expressed in terms of Al.sub.2 O.sub.3 (calculated as the anhydride), of aluminum is crystallized in an aqueous solution of an alkali metal hydroxide.

Process for preparation of mordenite type zeolite

A ferrierite type zeolite having a high purity and a high SiO.sub.2 /Al.sub.2 O.sub.3 molar ratio is prepared by reacting simultaneously and continuously an aqueous sodium and/or potassium silicate solution with an aluminum-containing solution to obtain a homogeneous phase compound of a granular amorphous aluminosilicate containing Al in an amount of 3 to 14 wt. % as calculated as anhydrous Al.sub.2 O.sub.3 and Na and/or K in an amount of 1 to 17 wt. % as calculated as anhydrous Na.sub.2 O and/or K.sub.2 O; and then, crystallizing the homogeneous phase compound in the form of a slurry in water or in an aqueous sodium hydroxide and/or potassium hydroxide solution. The molar ratio of K.sup.+ to the total of (K.sup.+ +Na.sup.+) in the slurry is 0.1 to 0.9.

Process for preparation of ferrierite type zeolites

A faujasite type zeolite having a high SiO.sub.2 /Al.sub.2 O.sub.3 ratio is prepared by simultaneously and continuously supplying an aqueous solution of an alkali metal silicate and an aqueous solution of an aluminum-containing compound whereby the alkali metal silicate is continuously reacted with the aluminum-containing compound to prepare a homogeneous phase compound of a granular amorphous aluminosilicate containing aluminum in an amount of 10 to 16% by weight, as Al.sub.2 O.sub.3 and based on the anhydride; and then, crystallizing the granular homogeneous phase amorphous aluminosilicate in an aqueous alkali metal hydroxide solution having a concentration of 4 to 10% by weight.

Process for preparation of high-silica faujasite type zeolite

A zeolite similar to ZSM-5, having lattice spacings (d-values), shown in Table 1, of the X-ray powder diffraction pattern, and a ferrierite zeolite are prepared by crystallizing a homogeneous phase compound of a granular amorphous aluminosilicate in water or in an aqueous solution of an alkali metal hydroxide and/or an alkali metal silicate.

Process for preparation of zeolites

A finely divided zeolite powder of high flowability is provided. This zeolite powder is represented by the formula: Na.sub.2 O.Al.sub.2 O.sub.3.nSiO.sub.2.wH.sub.2 O (n=1.8.about.3.0 and w=1.about.6) and comprises at least 99 weight % of particles having a particle size of 1-5 microns and has an aerated bulk density of from 0.3 to about 0.5 g/cc, a degree of cohesiveness of not larger than 56%, and a general flow index (expressed as the sum of indexes of the repose angle, spatula angle, compressibility and degree of cohesiveness) of from 30 to about 50. The zeolite powder is prepared by adding an alkali metal aluminate to an aqueous zeolite slurry containing 3052 wt. % of zeolite (an anhydride) and having pH of not higher than 12.8; adjusting the pH of the slurry to a value not higher than 11; and then, drying the slurry. The zeolite powder is useful as a builder for detergent.

Zeolite powder having high flowability, process for preparing same and

A Y-type zeolite having a SiO.sub.2 /Al.sub.2 O.sub.3 ratio of at least about 4 is produced by the following process. In the first step of the process, an aqueous alkali silicate solution and an aqueous alkali aluminate solution are mixed together in the presence of an alkali in an amount such that the ratio of M.sub.2 O(M: an alkali metal)/Al.sub.2 O.sub.3, present in the mixed solution, is at least about 5 by mole, followed by forming a gel in the mixed solution and, then, separating the gel therefrom. In the second step, the separated gel is incorporated in an aqueous alkali silicate solution or an aqueous alkali silicate-alkali mixed solution to obtain a slurry and, then, a Y-type zeolite crystal is formed in the slurry.

Process for producing Y-type zeolite

Zeolite substantially free from a free alkali ingredient is produced by a process wherein a silica source and an alumina source is reacted in an aqueous reaction medium containing an excessive amount of an alkali ingredient to form zeolite, followed by separating the so formed zeolite from the aqueous alkaline reaction medium or from an aqueous medium in which the zeolite, after being separated from the aqueous alkaline reaction medium, has been slurried. The separation of the zeolite from the aqueous alkaline reaction medium or from the aqueous medium, in which the zeolite has been slurried after being separated from the aqueous alkaline reaction medium, is effected in the added presence of an alkali metal or alkaline earth metal salt of aluminic acid.

Process of producing zeolite

A treatment for improving the filtering characteristics of the sludge is attained by adding a magnesium compound with or without an iron salt and further adding a base to maintain the pH of the sludge at higher than 9.0.

Treatment of sludge comprising biological aggregate

Light burned magnesia is added to sludge which comprises biological aggregate or polyvalent metal hydroxide aggregate to improve filtering characteristics.

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Shinnanyo, Japan

Hiroshi Miyazaki