Abstract: Applicants have developed a continuous process for synthesizing various molecular sieves. The process enables one to control both the particle size and particle size distribution. Any of the molecular sieves represented by the empirical formula on an anhydrous basis: rR.sub.2 O:(Si.sub.x Al.sub.y P.sub.z)O.sub.2, where R is at least one templating agent, "r" "x" "y" and "z" are the mole fractions of R, Si, Al and P respectively, can be prepared using this process. The process involves continuously adding reactive sources of the desired components along with a structure directing agent into a continuous crystallization reactor. Either interstage backmixing is introduced or the number of stages is adjusted in order to control particle size. Finally, one way to control particle size distribution is to split the product stream into at least two streams and flowing each stream to a wet miller operated at different severity and then reblending to obtain at least a bimodal distribution.

Abstract: The present invention relates to a process for synthesis of flyash based Zeolite-A, said process comprising grinding and mixing of flyash and caustic soda in a ratio of 1:1.2 and optionally adding sodium aluminate or aluminium hydroxide to obtain a fine homogeneous fusion mixture; heating the said mixture in an inert vessel at about 500-600.degree. C. for about 1-2 hrs. to obtain a fused mass; cooling, milling, and mixing the said fused mass in distilled water for about 8-10 hrs. with simultaneous optional additon of sodium aluminate or alum solution, in the present or absence of NaC1 followed by optional addition of zeolite-A seeding to obtain amorphous alumino -silicate slurry; subjecting the said slurry to hydrothermal crystallisation at about 90-110.degree. C. for 2 to 4 hrs. to obtain Zeolite-A crystals; and washing the said crystals with water and then subjecting the washed crystals to oven drying at about 50-60.degree. C. to obtain the FAZ-A crystals.

Abstract: This invention relates to zeolitic molecular sieve compositions characterized by outstanding capability to complex multivalent cations, especially calcium. In particular, the invention relates to novel zeolitic molecular sieve compositions, especially those based on molecular sieves having a high alumina-to-silica ratio, in which crystals of the zeolite are modified by the inclusion of occluded silicate.

Abstract: A microporous crystalline material named zeolite A-LSX having, in its anhydrous form, an oxides molar composition corresponding to formula (I):(M.sub.2/n O+M'.sub.2/n O).Al.sub.2 O.sub.3.zSiO.sub.2 (I)in which:M and M', identical or different, represent a cation of an alkali or alkaline earth metal of valency n;z is a number between 2.1 and 2.6, extremes included.Said microporous crystalline material can be used as a builder in detergent systems.

Abstract: Mild acid treatment of zeolite 3A molecular sieve to modify the pH of the surface of the molecular sieve to a pH ranging between 9.5 and 11 was found to significantly minimize the effect of the zeolite 3A on the pot life of non-foamed polyurethanes. Increases in pot life over untreated zeolite 3A molecular sieve were dramatic (about 400%) with less than 5% reduction in water adsorption capacity.

Abstract: The present invention relates to colloidal suspensions of discrete particles of colloidal zeolite and a method for preparing such zeolite from clear tetraalkylammonium stabilized aluminiumsilicate solutions. Smaller amounts of well defined and controlled metal hydroxide solutions are added to these alumiumsilicate solutions to enable the synthesis of a specific zeolite as well as to control zeolite yield. The colloidal suspensions are characterized by an average particle size of less than 250 nanometers and preferably, less than 200 nanometers together with the fact that the particle size distribution expressed as the geometric standard deviation is less than 1.30 and preferably less than 1.20. Zeolite sols synthesized according to this invention display Tyndall light scattering typical for colloidal suspensions as well as a very low rate of sedimentation due to the small particle size.

Abstract: Finely ground zeolithic alkali metal aluminum silicates having the general formula: xMe.sub.2 O.Al.sub.2 O.sub.3.ySiO.sub.2.zH.sub.2 O, are prepared by mixing both reaction components, alkali metal silicate and alkali metal aluminate, in the presence of a stoichiometrically excessive amount of alkali metal hydroxide. The thus obtained gel is matured, the reaction mixture is heated up to crystallisation temperature, then crystallised. During crystallisation, at least one of both reaction components is added to the reaction mixture.

Abstract: Crystalline 4A zeolites having high calcium ion exchange capacity, well adapted as builder materials for detergent compositions, are prepared by directly admixing an aqueous sodium silicate solution with a first aqueous sodium aluminate solution in a first reaction vessel to form a hydrogel therefrom, and transferring the hydrogel thus formed to a discrete crystallization zone and therein contacting such hydrogel with a crystallization-effecting amount of a second aqueous sodium aluminate solution to convert same into a crystalline 4A zeolite, and, advantageously, filtering, washing and optionally drying such crystalline 4A zeolite.

Abstract: The invention purpose is a process to obtain gel to elaborate Zeolite 4A, to be used in detergents due to its capacity for calcium absortion; the process lies on the obtention of an alkaline aluminum solution starting from bauxite provided by tank 3 which is attacked in digestor 1 with sodium hydroxide provided by tank 4, with a concentration of 11% minimum, with a filtration of the reacting mass and a purification 13 before the gel formation step in whose reactor 14 is also introduced an alkaline solution of SiO2 to obtain by agitation and temperature a gel which is treated in a crystallizer 15, cooling and concentrating the crystalline mass in 16, filtered in 17, and passed to a dryer 20 from where the product Zeolite 4A passes to storage 21. Bauxite residues are attacked with boiling sulphuric acid in reactor 9, filtering the resulting mass in 11 to recycle the silica and to recover the metal sulphates in solution for using them in water treatments.

Abstract: A method of producing zeolite particles with reduced carbonate species so that the zeolite particles are ion exchangeable with biocidal metal ions.