Abstract: A fixing carrier for fixing an activated sludge employed in a sewage or waste-water treatment in whicha clay, containing kaolinite minerals, of from 10 to 40 parts by weight and a foaming agent of from 5 to 20 parts by weight are blended with a granulated blast furnace slag of from 60 to 90 parts by weight in the presence of water to prepare a wet mixture which is kneaded and shaped into a shaped mixture; andsaid shaped mixture is baked at a baking temperature of less than 950.degree. C. at maximum, with the proviso that each of a heat-up time required of said shaped mixture to reach said baking temperature for producing a baked product and a heat-down time required of said baked product to reach a temperature of up to 100.degree. C. is about one hour.

Abstract: A fixing carrier for fixing an activated sludge employed in a sewage or waste-water treatment in which:a clay, containing kaolinite minerals, of from 10 to 40 parts by weight and a foaming agent of from 5 to 20 parts by weight are blended with a granulated blast furnace slag of from 60 to 90 parts by weight in the presence of water to prepare a wet mixture which is kneaded and shaped into a shaped mixture; andsaid shaped mixture is baked at a baking temperature of less than 950.degree. C. at maximum, with the proviso that each of a heat-up time required of said shaped mixture to reach said baking temperature for producing a baked product and a heat-down time required of said baked product to reach a temperature of up to 100.degree. C. is about one hour.

Abstract: An extrusion die for forming a honeycomb stucture has a lattice molding groove formed in the outlet surface of the die body. In the inlet surface of the die body there are formed plural independent supply passages that are opposite to the intersecting portions of the molding groove and extend toward the outlet surface. A through hole is designed to communicate adjacent supply passages at a place that forms part of the partition wall between the supply passages and contacts with the molding groove. This through hole takes the combined shape of a trapezoid with the width of the molding groove as its top side and with the diameter of the supply passage as its maximum base side and a semicircle having said base side as its diameter.