A tableted catalyst support, characterized by an alpha-alumina content of at least 85 wt.-%, a pore volume of at least 0.40 mL/g, as determined by mercury porosimetry, and a BET surface area of 0.5 to 5.0 m.sup.2/g. The tableted catalyst support is an alpha-alumina catalyst support obtained with high geometrical precision and displaying a high overall pore volume, thus allowing for impregnation with a high amount of silver, while exhibiting a surface area sufficiently large so as to provide optimal dispersion of catalytically active species, in particular metal species. The invention further provides a process for producing a tableted alpha-alumina catalyst support, which comprises i) forming a free-flowing feed mixture comprising, based on inorganic solids content, at least 50 wt.-% of a transition alumina; ii) tableting the free-flowing feed mixture to obtain a compacted body; and iii) heat treating the compacted body at a temperature of at least 1100° C., preferably at least 1300° C., more preferably at least 1400° C., in particular at least 1450° C., to obtain the tableted alpha-alumina catalyst support. The invention moreover relates to a compacted body obtained by tableting a free-flowing feed mixture which comprises, based on inorganic solids content, at least 50 wt.-% of a transition alumina having a loose bulk density of at most 600 g/L, a pore volume of at least 0.6 mL/g, as determined, and a median pore diameter of at least 15 nm. The invention moreover relates to a shaped catalyst body for producing ethylene oxide by gas-phase oxidation of ethylene, comprising at least 15 wt.-% of silver, relative to the total weight of the catalyst, deposited on the tableted alpha-alumina catalyst support. The invention moreover relates to a process for producing ethylene oxide by gas-phase oxidation of ethylene, comprising reacting ethylene and oxygen in the presence of the shaped catalyst body.

A tableted catalyst support, characterized by an alpha-alumina content of at least 85 wt.-%, a pore volume of at least 0.40 mL/g, as determined by mercury porosimetry, and a BET surface area of 0.5 to 5.0 m.sup.2/g. The tableted catalyst support is an alpha-alumina catalyst support obtained with high geometrical precision and displaying a high overall pore volume, thus allowing for impregnation with a high amount of silver, while exhibiting a surface area sufficiently large so as to provide optimal dispersion of catalytically active species, in particular metal species. The invention further provides a process for producing a tableted alpha-alumina catalyst support, which comprises i) forming a free-flowing feed mixture comprising, based on inorganic solids content, at least 50 wt.-% of a transition alumina; ii) tableting the free-flowing feed mixture to obtain a compacted body; and iii) heat treating the compacted body at a temperature of at least 1100° C., preferably at least 1300° C., more preferably at least 1400° C., in particular at least 1450° C., to obtain the tableted alpha-alumina catalyst support. The invention moreover relates to a compacted body obtained by tableting a free-flowing feed mixture which comprises, based on inorganic solids content, at least 50 wt.-% of a transition alumina having a loose bulk density of at most 600 g/L, a pore volume of at least 0.6 mL/g, as determined, and a median pore diameter of at least 15 nm. The invention moreover relates to a shaped catalyst body for producing ethylene oxide by gas-phase oxidation of ethylene, comprising at least 15 wt.-% of silver, relative to the total weight of the catalyst, deposited on the tableted alpha-alumina catalyst support. The invention moreover relates to a process for producing ethylene oxide by gas-phase oxidation of ethylene, comprising reacting ethylene and oxygen in the presence of the shaped catalyst body.

A porous ceramic filter having one or more coatings of elemental or compounds of iron, manganese, aluminum, titanium, or mixtures thereof deposited on the surface of the pores.

A porous ceramic filter having one or more coatings of elemental or compounds of iron, manganese, aluminum, titanium, or mixtures thereof deposited on the surface of the pores.

A process for producing a porous alpha-alumina catalyst support, comprising i) preparing a precursor material comprising, based on inorganic solids content, at least 50 wt.-% of a transition alumina having a loose bulk density of at most 600 g/L, a pore volume of at least 0.6 mL/g and a median pore diameter of at least 15 nm; and at most 30 wt.-% of an alumina hydrate; ii) forming the precursor material into shaped bodies; and iii) calcining the shaped bodies to obtain the porous alpha-alumina catalyst support. The catalyst support has a high overall pore volume, thus allowing for impregnation with a high amount of silver, while keeping its surface area sufficiently large so as to provide optimal dispersion of catalytically active species, in particular metal species. The invention further relates to a shaped catalyst body for producing ethylene oxide by gas-phase oxidation of ethylene, comprising at least 15 wt.-% of silver, relative to the total weight of the catalyst, deposited on a porous alpha-alumina catalyst support obtained in the process described above. The invention also relates to a process for preparing a shaped catalyst body as described above comprising impregnating a porous alpha-alumina catalyst support obtained in the process described above with a silver impregnation solution, preferably under reduced pressure; and optionally subjecting the impregnated porous alumina support to drying; and b) subjecting the impregnated porous alpha-alumina support to a heat treatment; wherein steps a) and b) are optionally repeated. The invention further relates to a process for producing ethylene oxide by gas-phase oxidation of ethylene, comprising reacting ethylene and oxygen in the presence of a shaped catalyst body as described above.

A process for producing a porous alpha-alumina catalyst support, comprising i) preparing a precursor material comprising, based on inorganic solids content, at least 50 wt.-% of a transition alumina having a loose bulk density of at most 600 g/L, a pore volume of at least 0.6 mL/g and a median pore diameter of at least 15 nm; and at most 30 wt.-% of an alumina hydrate; ii) forming the precursor material into shaped bodies; and iii) calcining the shaped bodies to obtain the porous alpha-alumina catalyst support. The catalyst support has a high overall pore volume, thus allowing for impregnation with a high amount of silver, while keeping its surface area sufficiently large so as to provide optimal dispersion of catalytically active species, in particular metal species. The invention further relates to a shaped catalyst body for producing ethylene oxide by gas-phase oxidation of ethylene, comprising at least 15 wt.-% of silver, relative to the total weight of the catalyst, deposited on a porous alpha-alumina catalyst support obtained in the process described above. The invention also relates to a process for preparing a shaped catalyst body as described above comprising impregnating a porous alpha-alumina catalyst support obtained in the process described above with a silver impregnation solution, preferably under reduced pressure; and optionally subjecting the impregnated porous alumina support to drying; and b) subjecting the impregnated porous alpha-alumina support to a heat treatment; wherein steps a) and b) are optionally repeated. The invention further relates to a process for producing ethylene oxide by gas-phase oxidation of ethylene, comprising reacting ethylene and oxygen in the presence of a shaped catalyst body as described above.

A method for preparing ceramsite by using municipal sludge as raw material, including the following specific steps: drying; preparing ingredients including raw sludge, fly ash, kaolinite, steelmaking slag, zeolite, hematite, calcareous shale, waste incineration fly ash, Fe.sub.2O.sub.3, waste glass, calcium carbonate, sodium lauryl sulfate, and sodium benzoate; mixing and stirring uniformly, and putting the stirred materials into a granulating machine for granulation; drying and preheating the material pellets after granulation, and then quickly transferring to a sintering device for first sintering at a low temperature and then sintering at a high temperature; crushing large chunks of the cooled materials; and separating and screening the crushed materials. The method of the present invention reduces the generation of the large chunks of the cooled materials in the obtained ceramsite, thereby reducing the subsequent crushing work and saving energy consumption accordingly.

A method for preparing ceramsite by using municipal sludge as raw material, including the following specific steps: drying; preparing ingredients including raw sludge, fly ash, kaolinite, steelmaking slag, zeolite, hematite, calcareous shale, waste incineration fly ash, Fe.sub.2O.sub.3, waste glass, calcium carbonate, sodium lauryl sulfate, and sodium benzoate; mixing and stirring uniformly, and putting the stirred materials into a granulating machine for granulation; drying and preheating the material pellets after granulation, and then quickly transferring to a sintering device for first sintering at a low temperature and then sintering at a high temperature; crushing large chunks of the cooled materials; and separating and screening the crushed materials. The method of the present invention reduces the generation of the large chunks of the cooled materials in the obtained ceramsite, thereby reducing the subsequent crushing work and saving energy consumption accordingly.

A method for preparing ceramsite by using municipal sludge as raw material, including the following specific steps: drying; preparing ingredients including raw sludge, fly ash, kaolinite, steelmaking slag, zeolite, hematite, calcareous shale, waste incineration fly ash, Fe.sub.2O.sub.3, waste glass, calcium carbonate, sodium lauryl sulfate, and sodium benzoate; mixing and stirring uniformly, and putting the stirred materials into a granulating machine for granulation; drying and preheating the material pellets after granulation, and then quickly transferring to a sintering device for first sintering at a low temperature and then sintering at a high temperature; crushing large chunks of the cooled materials; and separating and screening the crushed materials. The method of the present invention reduces the generation of the large chunks of the cooled materials in the obtained ceramsite, thereby reducing the subsequent crushing work and saving energy consumption accordingly.

A method for preparing ceramsite by using municipal sludge as raw material, including the following specific steps: drying; preparing ingredients including raw sludge, fly ash, kaolinite, steelmaking slag, zeolite, hematite, calcareous shale, waste incineration fly ash, Fe.sub.2O.sub.3, waste glass, calcium carbonate, sodium lauryl sulfate, and sodium benzoate; mixing and stirring uniformly, and putting the stirred materials into a granulating machine for granulation; drying and preheating the material pellets after granulation, and then quickly transferring to a sintering device for first sintering at a low temperature and then sintering at a high temperature; crushing large chunks of the cooled materials; and separating and screening the crushed materials. The method of the present invention reduces the generation of the large chunks of the cooled materials in the obtained ceramsite, thereby reducing the subsequent crushing work and saving energy consumption accordingly.