Patent ID: 6125660
Filing Date: 2000-10-03
Classification: C03B

Abstract:
Process for producing mineral fibers from rock, vitreous technical wastes or technical glass wastes, in which after the mechanical separation of non-glass-containing and predominantly glass-containing products the predominantly glass-containing products having a particle size of less than 80 mm are melted at 1050.degree. C. to 1480.degree. C. in a melting bath (1), where the melting bath (1) is connected to a forehearth (2) in such a manner that flow of the melt from the melting bath (1) into the forehearth (2) is enabled between melting bath (1) and forehearth (2) in the surface area of the melt, and where the melt is fed from the forehearth (2) to a feeder device, and where the melt is fed from the feeder device to a bushing device arranged there below and is taken off from there as filament with simultaneous solidification, comprising feeding the melt to the feeder device from a take-off area (8) of the melt in which the melt complies with the following conditions:a) the processing range of the melt is 40 to 100 K,b) the melt viscosity at 1450.degree. C. is 30 to 160 dPa.s,c) the melt viscosity at 1300.degree. C. is 200 to 1500 dPa.s,d) the quotient of the viscosity (in Pa.s) and the surface tension (in N/m) is between 10 and 100,e) the energy of activation of the viscous flow of the melt is no greater than 290 kJ/mol; andf) the ratio of the height (h.sub.S) of the melt in the forehearth to the height (h.sub.W) of the melt in the melting bath is (h.sub.S):(h.sub.W)=(0.8 to 1.1):(2 to 6): andg) the ratio of the area of the melt surface (4) in the melting bath (1) to the area of the melt surface (4) in the forehearth (2) is 0.5 to 1.5.