초록 ▼

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 of relatively large capacity, wherein the resultant zeolite precursor slurry is held at temperatures of u

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 of relatively large capacity, wherein the resultant zeolite precursor slurry is held at temperatures of up to 180°F. for 4-16 hours, with high shear agitation, as an induction period. The slurry is sent to a plurality of crystallization tanks 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 preferably operated in two stages. The first crystallizing stage is held at a temperature of 180°-250°F. for 2-72 hours. The second crystallizing stage is held at a temperature greater than 250°F. for 2-16 hours.

대표청구항 ▼

A method for preparing a variety of crystalline zeolites having selected crystal sizes, compositions, and pore sizes within a continuous manufacturing plant, comprising: A. forming a precursor slurry within a precursor tank which is held, as an induction stage, at a temperature below 200°F. for from

A method for preparing a variety of crystalline zeolites having selected crystal sizes, compositions, and pore sizes within a continuous manufacturing plant, comprising: A. forming a precursor slurry within a precursor tank which is held, as an induction stage, at a temperature below 200°F. for from 4 to 16 hours while crystallization nutrients and modifiers are continuously fed thereto to form a reaction mixture which is thoroughly and continuously homogenized with high shear agitation to produce said precursor slurry having a total solids content that is above 10% by weight of the slurry and a synthetic crystalline siliceous solid content not exceeding 15% by weight of said total solids content; and B. crystallizing said zeolites therein at temperatures greater than 180°F. and at pressures from autogenous to 400 psig for at least two hours in a first crystallization stage and at least one additional crystallization stage, wherein said first crystallization stage is operated in a separate reaction vessel from said at least one additional crystallization stage and wherein said at least one additional crystallization stage is conducted at a higher temperature than said first crystallization stage, and wherein the contents of said at least one additional crystallization stage are partially and selectively backmixed to said first crystallization stage.