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 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.

In a process for manufacturing a component for an emissions treatment unit, green ceramic product is extruded through a die to form an extrusion having a honeycomb substrate structure with an array of parallel, linear tubular cells extending along its length, the cells bounded by walls dividing adjacent cells from one another. A ceramic unit is obtained by cutting off, curing and firing a length of the extrusion a length of the extrusion. Following the firing, a mixture of a flowable, uncured curable material and a particulate metal component is injected from an end of the ceramic unit into selected ones of the cells so as to block the selected cells over at least a part of their lengths while maintaining all of the walls of the ceramic unit. The injected mixture is then cured to render it solid.

A method for producing a conductive honeycomb structure includes: a forming step of extruding a forming raw material to obtain a honeycomb formed body; 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 controlling a volume fraction of a portion that can form pores of the honeycomb formed body so that an absolute value of a difference in the volume fraction of the portion that can form the pores in predetermined regions of the honeycomb formed body relative to a previously set, predetermined porosity of the honeycomb fired body is within 0.5%. The predetermined porosity is a porosity preset for each of the predetermined regions of the honeycomb fired body.

In order to specify a catalytic converter, especially SCR catalytic converter, with maximum catalytic activity, this catalytic converter has at least one catalytically active component and additionally at least one porous inorganic filler component having meso- or macroporosity. The organic porous filler component has a proportion of about 5 to 50% by weight. More particularly, a diatomaceous earth or a pillared clay material is used as the porous inorganic filler component.

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.