OPTICALLY DETECTABLE, FLOATABLE, CERAMIZABLE LITHIUM-ALUMINA SILICATE-GLASS FREE OF ARSENIC AND FREE OF ANTIMONY

摘要

An optically detectable floatable ceramizable As- and Sb-free glass is provided to obtain a glass ceramic material detectable optically in a glass piece classification system and causing little or no colorization caused by Sn/Ti-complex formation. A glass ceramic material is obtained from optically detectable floatable As- and Sb-free ceramizable and thermally reinforcing treatable glass and has the following composition (expressed in wt% based on oxides): SiO2 55-69; Al2O3 19-25; Li2O 3.2-5; Na2O 0-1.5; K2O 0-1.5; MgO 0-2.2; CaO 0-2.0; SrO 0-2.0; BaO 0-2.5; ZnO 0- < 1.5; TiO2 1-3; ZrO2 1-2.5; SnO2 0.1- < 1; Sigma TiO2+ZrO2+SnO2 2.5-5; P2O5 0-3; Nd2O3 0.01-0.6; CoO 0-0.005; F 0-1; and B2O3 0-2. In the glass ceramic, Na2O and K2O are present in a combined weight of 0.1-2 wt%.