Abstract: The method of environmentally friendly melting and refining a glass melt of a crystallizable glass, which is used for making a lithium aluminum silicate (LAS) glass ceramic, includes the steps of providing a glass batch with a main batch composition within a lithium aluminum silicate (LAS) glass system, in which 0.1-<0.6% by weight of tin oxide has been added as main refining agent, but which does not contain arsenic oxide and/or antimony oxide as refining agent, formulating a raw material mixture for the glass batch, so that less than 40% by weight of the raw material mixture is quartz sand and then refining a glass melt formed from the glass batch at temperatures of at least 1600° C.

Abstract: The process for producing a transparent lithium aluminosilicate glass ceramic plate includes ceramicizing a green glass body of the Li2O—Al2O—SiO2 system using a ceramization program, which includes heating it, for the purpose of nucleation, to a temperature of 750° C.±20° C. and maintaining the temperature for 20±15 minutes, further heating the green glass body, for the purpose of ceramization, to a temperature of 900±20° C. and maintaining the to temperature for 20±15 minutes and then cooling to room temperature. The transparent plate has a thermal expansion coefficient (CTE) from ?0.15×10?6/K to +0.15×10?6/K at 30 to 700° C. and a brightness value observed at an angle of 2° of ?80 for a 4-mm thick plate for transmitted normal light.

Abstract: A transparent, dyed cooktop is provided that has improved color display capability. The cooktop is made of a glass ceramic having high quartz mixed crystals as the predominant crystal phase, wherein the glass ceramic comprises none of the chemical refining agents arsenic oxide and/or antimony oxide, except for inevitable trace amounts. The glass ceramic has transmission values of greater than 0.1% in the range of visible light over the entire wavelength range greater than 450 nm, light transmission in the visible range of 0.8 to 5%, and transmission in the infrared at 1600 nm of 45-85%. The glass ceramic also includes a display apparatus that has a display device which is designed to display different operating conditions with different colors and/or symbols.

Abstract: Transparent, dyed cook top or hob with improved color display capability, consisting of a glass ceramic with high quartz mixed crystals as predominant crystal phase, whereby the glass-ceramic contains none of the chemical refining agents arsenic oxide and/or antimony, with transmission values of greater than 0.1% in the range of the visible light within the entire wavelength range greater than 450 nm, a light transmission in the visible of 0.8-2.5% and a transmission in the infrared at 1600 nm of 45-85%.

Abstract: Transparent, dyed cook top or hob with improved color display capability, consisting of a glass ceramic with high quartz mixed crystals as predominant crystal phase, whereby the glass-ceramic contains none of the chemical refining agents arsenic oxide and/or antimony, with transmission values of greater than 0.1% in the range of the visible light within the entire wavelength range greater than 450 nm, a light transmission in the visible of 0.8-2.5% and a transmission in the infrared at 1600 nm of 45-85%.

Abstract: The armored or bulletproof glass include a transparent plate laminate, which includes one or more transparent glass ceramic plates made from a green glass body of the Li2O—Al2O3—SiO2 system, optionally one or more additional plates made of plastic material, and optionally one or more glass plates. The glass ceramic plate preferably has a thermal expansion coefficient of ?0.05×10?6/K to ?0.10×10?6/K at 30 to 700° C. and a brightness value for transmitted normal light at an angle of 2°?80 for a 4-mm thick plate. The transparent plate laminate preferably has a total of 4 to 8 plates and a thickness between 40 and 80 mm. A bulletproof vest, a fire prevention glazing, a fireplace viewing window pane, a cooktop, a magnetic storage plate or a substrate for semiconductor materials also advantageously include the transparent plate laminate described here.

Abstract: The process for producing a transparent lithium aluminosilicate glass ceramic plate includes ceramicizing a green glass body of the Li2O—Al2O—SiO2 system using a ceramization program, which includes heating it, for the purpose of nucleation, to a temperature of 750° C.±20° C. and maintaining the temperature for 20±15 minutes, further heating the green glass body, for the purpose of ceramization, to a temperature of 900±20° C. and maintaining the to temperature for 20±15 minutes and then cooling to room temperature. The transparent plate has a thermal expansion coefficient (CTE) from ?0.15×10?6/K to +0.15×10?6/K at 30 to 700° C. and a brightness value observed at an angle of 2° of ?80 for a 4-mm thick plate for transmitted normal light.

Abstract: A glass ceramic as cooktop for induction heating having improved colored display capability and heat shielding is provided. The cooktop includes a transparent, dyed glass ceramic plate having high-quartz mixed crystals as a predominant crystal phase. The glass ceramic contains none of the chemical refining agents arsenic oxide and/or antimony oxide and has a transmittance values greater than 0.4% at at least one wavelength in the blue spectrum between 380 and 500 nm, a transmittance >2% at 630 nm, a transmittance of less than 45% at 1600 nm, and a light transmittance of less than 2.5% in the visible spectrum.

Abstract: A glass ceramic article is provided so that a reliable coloring with a defined transmittance is ensured. The reliable coloring of the glass ceramic article is based on a high content of iron oxide of more than 0.1 percent by weight which itself has a strongly coloring effect does not further reduce transmittance but rather interacts with vanadium oxide to attenuate the absorption caused by vanadium oxide.

Abstract: A method of manufacturing glass ceramic articles such as glass ceramic plates for cooktops or fireplace windows is provided. The method facilitates the adjustment of a specific hue or a specific absorptivity of the glass ceramic in the visible spectral range. The method is based on the finding that the absorption of light by coloring agents which are appropriate for or present in glass ceramics can be attenuated during the ceramization process by adding substances that have a decoloring effect.

Abstract: A method for producing bubble-free glasses is provided, in which a glass mixture that is arsenic-free and antimony-free with the exception of any unavoidable raw material impurities and a sulfate compound and SnO2 as refining agents are used. The glass mixture is melted and primarily refined in a first region of a melting tank, an average melting temperature (T1) is set at T1>1560° C. and an average melt residence time (t1) is set at t1>2 hours. The proportion of SO3 resulting from the decomposition of the sulfate compound is reduced to less than 0.002 wt. % as the primary refinement is carried out. A secondary refinement is carried out in a second region of the melting tank, an average melting temperature (T2) is set at T2>1640° C. and an average melt residence time (t2) is set at t2>1 hour.

Abstract: A transparent low-colour lithium aluminium silicate (LAS) glass ceramic and the use thereof are provided. The ceramic has an environmentally friendly composition with high-quartz mixed crystals as the main crystal phase. The glass ceramic contains the following components (in wt % on the basis of oxide): TiO2 1.6-<2.5; Nd2O3 0.005-0.15; MgO 0.2-1.0; ZnO 1-2.5; CaO+SrO 0-1.5; BaO 0-1.5 with the condition B1: MgO+ZnO>CaO+SrO+BaO. In some embodiments, the glass ceramic has a hue c* of less than 5.5, a light transmission Y greater than 81% and has no visually disruptive diffusion.

Abstract: A method for producing bubble-free glasses is provided, in which a glass mixture that is arsenic-free, antimony-free and tin-free with the exception of any unavoidable raw material impurities and at least one sulfate compound as a refining agent are used. The glass mixture and refining agent are melted and primarily refined in a first region of a melting tank, an average melting temperature (T1) is set at T1>1580° C. and an average melt residence time (t1) is set at t1>2 hours. A secondary refinement is carried out in a second region, an average melting temperature (T2) is set at T2>1660° C. and an average melt residence time (t2) is set at t2>1 hour, and the proportion of the SO3 resulting from decomposition of the sulfate is reduced to less than 0.002 wt. %.

Abstract: A glass having excellent resistance against surface damages is provided. The glass includes a content of alkaline earth oxides of at least 0.3% by weight and of P2O5 of 0.1 to 4% by weight; the glass has at least one surface that has precipitations with a mean size of 1 to 20 ?m. A method is further provided and includes melting a glass batch, yielding a glass melt, and casting the glass melt onto a float bath. The glass melt is maintained on the float bath at a temperature of above 1000° C. for at least 5 minutes, and yields glass. The glass has a content of alkaline earth oxides of at least 0.3% by weight and of P2O5 of 0.1 to 4% by weight, and the glass has at least one surface that has precipitations with a mean size of 1 to 20 ?m.

Abstract: The armored or bulletproof glass include a transparent plate laminate, which includes one or more transparent glass ceramic plates made from a green glass body of the Li2O—Al2O3—SiO2 system, optionally one or more additional plates made of plastic material, and optionally one or more glass plates. The glass ceramic plate preferably has a thermal expansion coefficient of ?0.05×10?6/K to ?0.10×10?6/K at 30 to 700° C. and a brightness value for transmitted normal light at an angle of 2°?80 for a 4-mm thick plate. The transparent plate laminate preferably has a total of 4 to 8 plates and a thickness between 40 and 80 mm. A bulletproof vest, a fire prevention glazing, a fireplace viewing window pane, a cooktop, a magnetic storage plate or a substrate for semiconductor materials also advantageously include the transparent plate laminate described here.

Abstract: The process for producing a transparent lithium aluminosilicate glass ceramic plate includes ceramicizing a green glass body of the Li2O—Al2O—SiO2 system using a ceramization program, which includes heating it, for the purpose of nucleation, to a temperature of 750° C.±20° C. and maintaining the temperature for 20±15 minutes, further heating the green glass body, for the purpose of ceramization, to a temperature of 900±20° C. and maintaining the to temperature for 20±15 minutes and then cooling to room temperature. The transparent plate has a thermal expansion coefficient (CTE) from ?0.15×10?6/K to +0.15×10?6/K at 30 to 700° C. and a brightness value observed at an angle of 2° of ?80 for a 4-mm thick plate for transmitted normal light.

Abstract: A method is described for making a float glass convertible into a glass ceramic, by which a largely crystal fault-free glass can be produced. In this method the glass is cooled from a temperature (TKGmax), at which a crystal growth rate is at a maximum value (KGmax), to another temperature (TUEG), at which practically no more crystal growth occurs, with a cooling rate, KR, in ° C. min?1 according to: KR UEG KGmax ? ? ? ? T UEG KGmax 100 · KG ? ? max , wherein ?T=TKGmax?TUEG, and KGmax=maximum crystal growth rate in ?m min?1. The float glass has a thickness below an equilibrium thickness, a net width of at least 1 m and has no more than 50 crystals with a size of more than 50 ?m, especially no crystals with a size of more than 10 ?m, per kilogram of glass within the net width.

Abstract: A lithium-aluminosilicate glass or a corresponding glass ceramic that has a content of 0-0.4SnO2, 1.3-2.7% by weight of ?SnO2+TiO2, 1.3-2.5% by weight of ZrO2, 3.65-4.3% by weight of ?ZrO2+0.87 (TiO2+SnO2), ?0.04% by weight of Fe2O3, 50-4000 ppm of Nd2O3 and 0-50 ppm of CoO is described. The glass or the glass ceramic is color-neutral, has a turbidity of less than 1% HAZE and a high light transmission. The glazing time for conversion of the glass into glass ceramic is especially short with less than 2.5 hours.

Abstract: A colorless transparent colloid-former-containing glass that is convertible into a colorless transparent glass ceramic or a metal colloid-colored glass ceramic via respective heat treatments contains a combination of one or more metal colloid formers and one or more redox partners. The metal colloid formers are preferably oxides containing Au, Ag, As, Bi, Nb, Cu, Fe, Pd, Pt, Sb and/or Sn. The redox partners are preferably oxides containing As, Ce, Fe, Mn, Sb, Sn and/or W, with the proviso that the redox partner must be different from the metal colloid former. The glass advantageously contains from 0.97 to 1.9 wt. % SnO2, 0.93 to 3.0 wt. % As2O3, or 1.59 to 6.0 wt. % of Sb2O3 as redox partner.

Abstract: A glass ceramic as cooktop for induction heating having improved colored display capability and heat shielding is provided. The cooktop includes a transparent, dyed glass ceramic plate having high-quartz mixed crystals as a predominant crystal phase. The glass ceramic contains none of the chemical refining agents arsenic oxide and/or antimony oxide and has a transmittance values greater than 0.4% at at least one wavelength in the blue spectrum between 380 and 500 nm, a transmittance >2% at 630 nm, a transmittance of less than 45% at 1600 nm, and a light transmittance of less than 2.5% in the visible spectrum.