Abstract: The invention relates to the use of glass ceramics based on a high quartz mixed crystal system for dental purposes, which can be easily mechanically processed in an intermediate stage of crystallization and present high-strength, highly translucent and chemically stable glass ceramics following complete crystallization, wherein said glass or ceramics still have phosphorus and a transition metal compound, selected from titanium and zirconium or a mixture thereof.

Abstract: The present invention relates to a method for producing a granulate from waste glass for the manufacture of mineral wool products, such as mineral wool board or mineral wool web, in particular biosoluble glass wool obtained with the aid of at least one spinner having the form of a spinner basket, the peripheral wall of which includes a multiplicity of small-diameter outlet orifices through which a molten glass material is spun off in the form of filaments that are subjected to a supplementary attenuating action of a preferably downwardly directed gas flow, wherein a part of the molten glass material is constituted by glass fragments including foreign matter proportions in a ground form, the granulometry of which is the same size or smaller than the smallest diameter of the outlet orifices in the peripheral wall of the spinner.

Abstract: Mineral fiber composition which is decomposable in the physiological medium, characterized by the following constituents in weight percent: SiO.sub.2 30 to less than 51; Al.sub.2 O.sub.3 higher than 11.5, in particular higher than 13,up to 25; CaO 2 to less than 23; MgO 0 to 15; Na.sub.2 O+K.sub.2 O higher than 10, up to 19; TiO.sub.2 +Fe.sub.2 O.sub.3 6 to 18; various 0 to 3.