A honeycomb body (300) including a plurality of radially-extending walls (322) intersecting with a plurality of circumferentially-extending walls (324), the plurality of radially-extending walls (322) and the plurality of circumferentially-extending walls (324) form a plurality of circumferential zones (334A, 334B, 334C) of cells (308). The plurality of circumferential zones (334A, 334B, 334C) of cells (308) includes a first zone of cells (334A) including two or more first rings of cells (330) and having a first cell density, and a second zone of cells (334B) including two or more rings of cells (330) having varying cell densities across the two or more rings of cells. Other structures and extrusion dies are disclosed.

A thermal formation sintering compound containing a binder, a sinterable powder material and a pore formation material, for formation into a predetermined shape in a thermal formation step, removal of the binder in a degreasing step, and sintering of the powder material in a sintering step is provided. The binder contains a low-temperature draining component which melts in the thermal formation step, begins draining at a temperature lower than a draining temperature of the pore formation material, and drains at a temperature lower than a temperature at which the pore formation material drains; and a high-temperature draining component which melts in the thermal formation step, begins draining after the pore formation material begins draining, and drains at a temperature higher than does the pore formation material.

A vehicular exhaust filter comprising a porous substrate having an inlet face and an outlet face with the porous substrate comprising inlet channels extending from the inlet face and outlet channels extending from the outlet face is disclosed. The inlet channels and the outlet channels are separated by a plurality of filter walls having a porous structure. The vehicular exhaust filter is loaded with a refractory powder having a tapped density before loading of less than 0.10 g/cm.sup.3 and the vehicular exhaust filter has a mass loading of the refractory powder of less than 10 g/l.

A wall-flow honeycomb catalyst for dust removal and low-temperature denitrification of flue gas, and a preparation process thereof are provided. The catalyst is prepared from the following raw materials in parts by weight: calcined titanium dioxide: 30 to 60 parts; crude titanium dioxide: 30 to 50 parts; boehmite: 3 to 5 parts; fused silica powder: 2 to 4 parts; binder: 0.5 to 2 parts; lubricant: 0.5 to 2 parts; vanadium-molybdenum composite oxide: 5 to 10 parts; and water: 150 to 200 parts; and the vanadium-molybdenum composite oxide is obtained by dissolving ammonium metavanadate and ammonium molybdate in an oxalic acid solution and spray-drying a resulting solution. The preparation process of the catalyst of the present disclosure is simple and low in cost.

A porous ceramic honeycomb body (10) including intersecting walls that form channels (22) extending axially from a first end face to a second end face and layered plugs (62) comprised of a first layer (64) disposed on channel walls and a second layer (66) disposed inward toward an axial center of each respective channel on the first layer. The plugs seal at least one of a first portion of the channels at the first end face and a second portion of channels at the second end face of the porous ceramic honeycomb body.

A precursor mixture for producing a porous body, wherein the precursor mixture comprises: (i) at least one milled alpha alumina powder having a particle size of 0.1 to 6 microns, (ii) non-silicate powder that functions as a binder of the alpha alumina powders, and (iii) at least one burnout material having a particle size of 1-10 microns and a decomposition temperature of less than 550° C., with the proviso that a burnout material having a decomposition temperature of 550° C. or greater is excluded from the precursor mixture.

The present disclosure relates to a porous ceramic media that may include a chemical composition, a phase composition, a total open porosity content of at least about 10 vol. % and not greater than about 70 vol. % as a percentage of the total volume of the ceramic media, and a nitric acid resistance parameter of not greater than about 500 ppm. The chemical composition for the porous ceramic media may include SiO.sub.2, Al.sub.2O.sub.3, an alkali component and a secondary metal oxide component selected from the group consisting of an Fe oxide, a Ti oxide, a Ca oxide, a Mg oxide and combinations thereof. The phase composition may include an amorphous silicate, quartz and mullite.

The present invention relates to a wall-flow filter, to a method for the production and the use thereof in order to reduce harmful exhaust gases of an internal combustion engine. The wall-flow filter was produced by applying a powder-gas aerosol to the filter, whereby the powder was deposited in the pores of the wall-flow filter.

A honeycomb structure according to at least one embodiment of the present invention includes: partition walls defining cells each extending from a first end surface of the honeycomb structure to a second end surface thereof to form a fluid flow path; and an outer peripheral wall. The partition walls and the outer peripheral wall are each formed of ceramics containing silicon carbide and silicon. A surface of the silicon has formed thereon an oxide film having a thickness of from 0.1 μm to 5.0 μm.

A method for producing a honeycomb structure according to the present invention includes: a preparation step of preparing a honeycomb structure element 2 having plurality of slits 12; and a filling step of filling the plurality of slits 12 with a filling material 13 by a contacting member 3 by feeding the filling material 13 to an outer peripheral surface 20 of the honeycomb structure element 2, and rotating the honeycomb structure element 2 while pressing a tip portion 3a of the contacting member 3 inclined at an angle relative to a normal line 20a of the outer peripheral surface 20 of the honeycomb structure element 2 against the outer peripheral surface 20 with a force, to obtain the honeycomb structure having the plurality of slits 12 filled with the filling material 13.