Dense Barium Crown Glass
Dense Barium Crown Glass is referred to as ZK glass. The refractive index and density are larger than BaK glass, which is basically a borosilicate glass containing barium and zinc. The sum of the mass fraction of BaO and ZnO is greater than 40%. The ratio of ZnO to BaO affects the average dispersion. The chemical stability of this kind of glass is poor, and a small amount of Al2O3 is usually added to improve it. Due to the high content of BaO, the general clay refractories are severely eroded during melting, so platinum containers are mostly used for smelting. Mainly used as a material for optical parts in optical instruments, such as optical lenses, prism and Cylindrical lenses.
By modifying the glass formula, the optical glass without lead, arsenic and cadmium and other radioactive elements is expressed by a prefix "H-" indicating its envioronment-friendly characteristics, for example: H-ZK10
