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.

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.

Disclosed are a honeycomb structure body, a honeycomb structure filter and an extrusion molding die for a honeycomb structure body, which belong to the field of vehicle exhaust purification materials. The honeycomb structure body includes a honeycomb body and a skin layer around the honeycomb body, the honeycomb body including axially-extending channels defined by a porous wall, wherein a radial path of a radial section of the honeycomb body from a central axis to the skin layer consists of a porous wall inner section and a porous wall outer section in sequence, an average wall thickness of inner porous walls provided in the porous wall inner section is smaller than an average wall thickness of outer porous walls provided in the porous wall outer section, and a length of the porous wall inner section in the radial path accounts for 71%-95%. The arrangement of the specific structure of the honeycomb structure body of the present application not only increases the strength of the honeycomb structure body, but also ensures good thermal shock resistance and small back pressure of the honeycomb structure body; and the honeycomb structure body of the present application is prepared by integral molding, thereby achieving high production efficiency and low preparation cost.

A ceramic honeycomb filter comprising a cordierite-type ceramic honeycomb structure having large numbers of flow paths partitioned by porous cell walls, and plugs formed in end portions of predetermined flow paths of the ceramic honeycomb structure; the cell walls having a thermal expansion coefficient Tw (×10.sup.−7/° C.) of 10 or less in the flow path direction between 40° C. and 800° C.; the plugs comprising at least ceramic particles, and 5-25 parts by mass of an amorphous oxide matrix per 100 parts by mass of the ceramic particles; the ceramic particles comprising at least 42-90% by mass of amorphous silica particles, and 10-58% by mass of cordierite particles; and the amorphous silica particles comprising 4-30% by mass of first silica particles having a median particle diameter of 10-40 μm, and 70-96% by mass of second silica particles having a median particle diameter of 70-200 μm.

A honeycomb filter includes a pillar-shaped honeycomb structure having porous partition walls provided, surrounding a plurality of cells which serve as fluid through channels extending from an inflow end face to an outflow end face, and porous plugging portions provided either at the ends on the inflow end face or the outflow end face of the cells, wherein the plugging portions are composed of a porous material, the honeycomb structure has a central region and a circumferential region, and a ratio of an area of the circumferential region with respect to that of the central region ranges from 0.1 to 0.5, a plugging length L1 in the cell extending direction of a central plugging portion in the central region is larger than a plugging length L2 of a circumferential plugging portion in the circumferential region, L1 ranges from 7 to 9 mm, and L2 from 3 to 6 mm.

A scraping device for undried joining material protruding from a segment joint body in which side surfaces of a plurality of pillar-shaped honeycomb structure segments are joined via the undried joining material, the segment joint body having an outer peripheral side surface, a first honeycomb-shaped end surface, and a second honeycomb-shaped end surface located on an opposite side of the first honeycomb-shaped end surface, the scraping device includes a stand for placing the segment joint body; a controller; and a scraping robot comprising at least one scraping spatula configured to be movable in at least one scraping direction along at least one surface of the outer peripheral side surface, the first honeycomb-shaped end surface, and the second honeycomb-shaped end surface while being pressed against the at least one surface.

A ceramic honeycomb structure includes: an outer peripheral wall; and a partition wall disposed on an inner side of the outer peripheral wall, the partition wall defining a plurality of cells, each of the plurality of cells to form a fluid flow path extending from one end face to other end face. The honeycomb structure contains: 1) particles including one or more selected from silicon carbide, silicon nitride and aluminum nitride; and 2) silicon doped with a dopant. The dopant is a Group 13 element or a Group 15 element. The honeycomb structure has a silicon content (B) of from 20 to 80% by mass, and the honeycomb structure has a porosity of 30% or less.

A method for producing a ceramic honeycomb structure including at least one slit filled with a filling material in a cross section in an axial direction of the honeycomb structure, wherein the honeycomb structure includes: an outer peripheral wall; and a partition wall, the partition wall defining a plurality of cells, wherein the method includes the steps of: preparing a honeycomb structure element comprising at least one slit; masking one end face of the honeycomb structure element except for the slit; and providing the honeycomb structure comprising the at least one slit filled with the filling material by applying a pressure to an axial direction of the honeycomb structure element and feeding the filling material from the one end face to intrude the filling material from the slit on the one end face side to the slit on the other end face side.

A method for producing a honeycomb structure includes: a forming step of extruding a forming raw material containing a ceramic raw material to obtain a honeycomb formed body, the honeycomb formed body including: an outer peripheral wall; and partition walls disposed on an inner side of the outer peripheral wall, the partition walls defining a plurality of cells, each of the plurality of cells extending from one end face to the other end face to form a flow passage; a drying step of drying the honeycomb formed body to obtain a honeycomb dried body; and a firing step of firing the honeycomb dried body to obtain a honeycomb fired body. The forming step includes extruding the forming raw material to produce a honeycomb formed body in which a part of the partition walls is lost so that some of the cells are connected to each other.

A porous honeycomb structure including cell channels passing through an interior of the porous honeycomb structure and partitioned by porous partition walls, wherein the porous partition walls include skeleton portions containing an aggregate and a bonding material, and pore portions formed among the skeleton portions and through which a fluid can flow; and the porous partition walls have a porosity of 40 to 48% as measured by a mercury intrusion method, and a cumulative 50% pore diameter (D50) from a large pore side of 6 to 10 μm in a volume-based cumulative distribution of pore diameters measured by the mercury intrusion method, and a maximum pore diameter observed with a scanning electron microscope of 40 μm or less, and a ratio of a contact area between the aggregate and the bonding material to a surface area of the bonding material observed with the scanning electron microscope of 61 to 80%.