Verfahren zur Bindung teilchenfoermiger Materialien

摘要

Self-bonded bodies of particulate materials (e.g. oxides, carbides, borides, nitrides) are made by heating a shaped mixture of the material and 1-10% by wt. of an additive which includes an organic moiety and an inorganic moiety and is non-polymeric in respect of the inorganic moiety, and which thermally decomposes, without substantial prior evaporation, to leave a pyrolytic residue not less than 5% by wt. of the undecomposed additive (exclusive of any free carbon formed); and heating further to a temperature at which the particulate material becomes self-bonding and the inorganic residue of the additive remains substantiate involatile. The additive, which may be mixed with the particulate material before or after shaping, may be a neutral metal organo-phosphate, organo-phosphite or organo-hypophosphate or a corresponding thio analogue, in which there are P-O-C, P-S-C or P-C bonds; an organo silicon or metallo-organo silicon compound; or an organo-vanadium, organo-zirconium or organo-titanium compound; or a metal alcoholate or thio alcoholate. The particulate material, to which a conventional green strength binder may be added in addition to the heat-decomposable additive, may be an oxide containing mineral, e.g. corundum, bauxite mullite or magnesia; silica or silica-containing material, e.g. quartz, silica glass or porcelain including rejects; or a carbide, e.g. silicon carbide.