US 5,972,835 A · Fluidizable particulate materials and methods of making same

Abstract

The invention provides fluidizable, substantially spherical particulate material of improved attrition resistance having an average particle size from about 100 to about 400 microns useful as sorbents, catalysts, catalytic supports, specialty ceramics or the like. The particles are prepared by spray drying a slurry comprising inorganic starting materials and an organic binder. Exemplary inorganic starting materials include mixtures of zinc oxide with titanium dioxide, or with iron oxide, alumina or the like. Exemplary organic binders include polyvinyl alcohol, hydroxypropylemethyl cellulose, polyvinyl acetate and the like. The spray dried particles are heat treated at a first temperature wherein organic binder material is removed to thereby provide a porous structure to the particles, and thereafter the particles are calcined at a higher temperature to cause reaction of the inorganic starting materials and to thereby form the final inorganic particulate material.

Claims49

Dependent claims

A process for making attrition resistant spray dried fluidizable particles having an average particle size of between 100 and 400 microns, comprising:

forming an aqueous slurry comprising a plurality of inorganic starting materials selected from the group consisting of metal oxides and silica and an organic binder;
spray drying the slurry to produce substantially spherical precursor particles;
heating the precursor particles to a temperature between about 300.degree. C. and about 600.degree. C. in an oxidizing atmosphere and for a time sufficient to remove greater than about 50 wt. % of the organic binder to thereby provide a porous structure to said precursor particles;
and
heating the particles of porous structure to an increased calcination temperature between about 750.degree. C. and about 900.degree. C. in an oxidizing atmosphere and for a time sufficient to cause the inorganic materials to form an inorganic reaction product and thereby for said fluidizable particles of said average particle size.

2 more elements

A process for preparing a zinc titanate sorbent material in the form of fluidizable attrition resistant particles having an average particle size between 100 and 400 microns and capable of absorbing sulfur compounds from a gaseous feed, said process comprising:

(a) forming a zinc oxide/titanium dioxide dry blend comprising between about 0.5 and about 2 parts particulate zinc oxide having a median particle size of less than about 0.5 micron, and about 1 part particulate titanium dioxide having a median particle size of less than about 1 micron;
(b) preparing a substantially uniform aqueous slurry comprising said zinc oxide/titanium dioxide dry blend, organic binder, and inorganic binder, and wherein said slurry comprises substantially no free silica;
(c) spray drying the slurry to produce substantially spherical precursor particles;
(d) heating the precursor particles to a temperature between about 300.degree. C. and about 600.degree. C. in an oxidizing atmosphere and for a time sufficient to remove greater than about 50 wt. % of the organic binder;
and
(e) calcining said particles at a temperature of between about 750.degree. C. and about 900.degree. C. in an oxidizing atmosphere for a time sufficient to convert the zinc oxide and titanium dioxide to zinc titanate and thereby form said fluidizable particles of said average particle size.

3 more elements

Dependencies are inferred from the claim text.

Fluidizable particulate materials and methods of making same

Life of this patent

Fluidizable particulate materials and methods of making same

Life of this patent

Abstract

Claims49