Abstract: Thermoplastic compositions useful for producing metallic moldings containA) 40-65% by volume of a sinterable pulverulent metal or of a pulverulent metal alloy or of a mixture thereof,B) 35-60% by volume of a mixture ofB1) 85-100% by weight of a polyoxymethylene homopolymer or copolymer andB2) 0-15% by weight of a polymer homogeneously dissolved in B1) or dispersed therein with an average particle size of less than 1 .mu.m,C) 0-5% by volume of a dispersant.

Abstract: Pourable molding compounds containing sinterable powders contain, based on the total compound,a) from 60 to 95% by weight of sinterable powders,b) from 0.1 to 10% by weight of a surfactant, obtainable by alkoxylation of an aliphatic alcohol, fatty acid, fatty acid amide, fatty acid ester or aliphatic amine,c) from 2 to 35% by weight of an organic solvent having a melting point <10.degree. C. and a boiling point of from 40.degree. to 180.degree. C., selected from the group comprising the alkanes, ethers, esters and ketones.

Abstract: Preforms are produced from ceramic and/or metallic fibers by injection molding or extruding a mixture containing the fibers and a thermoplastic binder, said thermoplastic binder being polyoxymethylene, which after the shaping is removed by treatment in a gaseous acid-containing atmosphere or in a gaseous BF.sub.3 -containing atmosphere.

Abstract: Thermoplastic materials for the production of ceramic moldings containA) 40-65% by volume of a sinterable inorganic non-metallic powder,B) 35-60% by volume of a mixture ofB1) 70-90% by weight of a polyoxymethylene homo- or copolymer having up to 10 mol % of comonomer units andB2) 10-30% by weight of a polyoxymethylene copolymer with a comonomer content of 20-99 mol %, poly-1,3-dioxolane, poly-1,3-dioxane or poly-1,3-dioxepan, or of a polymer which is homogeneously dissolved or is dispersed with a mean particle size of less than 1 .mu.m in B1) or a mixture thereof,as a binder, andC) 0-5% by volume of a dispersant.

Abstract: Catalyst precursor units, e.g. for ammonia synthesis catalysts, comprise an iron oxide composition in the form of sintered shaped units of substantially uniform cross section having a plurality, e.g. 13 to 50 or more, through passages of substantially uniform cross section. The passages preferably have a diameter of less than 1.5, particularly less than 0.7, mm.