In the glass industry, a variety of rare metal compounds, small metal compounds, and rare earth compounds are used as functional additives or modifiers to achieve specific optical, physical, or chemical properties. Based on a large number of customer use cases, the technical and development team of UrbanMines Tech. Limited has classified and sorted out the following main compounds and their uses:
1. Rare earth compounds
1. Cerium Oxide (CeO₂)
- Purpose:
- Decolorizer: Removes green tint in glass (Fe²⁺ impurities).
- UV absorption: used in UV-protected glass (e.g. glasses, architectural glass).
- Polishing agent: polishing material for precision optical glass.
2. Neodymium oxide (Nd₂O₃), praseodymium oxide (Pr₆O₁₁)
- Purpose:
- Colorants: Neodymium gives the glass a purple color (varies with the light source), and praseodymium produces a green or yellow tint, often used in art glass and filters.
3. Eu₂O₃, Terbium Oxide (Tb₄O₇)
- Purpose:
- Fluorescent properties: used for fluorescent glass (such as X-ray intensifying screens, and display devices).
4. Lanthanum oxide (La₂O₃), yttrium oxide (Y₂O₃)
- Purpose:
- High refractive index glass: Increase the refractive index of optical glass (such as camera lenses, and microscopes).
- High-temperature resistant glass: Enhanced thermal resistance and chemical stability (labware, optical fibers).
2. Rare Metal Compounds
Rare metals are often used in glass for special functional coatings or performance optimization:
1. Indium Tin Oxide (ITO, In₂O₃-SnO₂)
- Purpose:
- Conductive coating: Transparent conductive film used for touch screens and liquid crystal displays (LCDs).
2. Germanium oxide (GeO₂)
- Purpose:
- Infrared Transmitting Glass: Used in thermal imagers, and infrared optical devices.
- High refractive index fiber: Improves the performance of optical fiber communications.
3. Gallium oxide (Ga₂O₃)
- Purpose:
- Blue light absorption: used in filters or special optical glasses.
3. Minor Metal Compounds
Minor metals usually refer to metals with low production but high industrial value, which are often used for coloring or performance adjustment:
1. Cobalt oxide (CoO/Co₃O₄)
- Purpose:
- Blue colorant: used in art glass, and filters (such as sapphire glass).
2. Nickel Oxide (NiO)
- Purpose:
- Grey/Purple Tinting: Adjusts the color of the glass, and can also be used for thermal control glass (absorbs specific wavelengths).
3. Selenium (Se) and selenium oxide (SeO₂)
- Purpose:
- Red coloration: Ruby glass (combined with cadmium sulfide).
- Decolorizer: Neutralizes the green tint caused by iron impurities.
4. Lithium Oxide (Li₂O)
- Purpose:
- Lower melting point: Improve the molten fluidity of glass (such as special glass, optical glass).
4. Other functional compounds
1. Titanium oxide (TiO₂)
- Purpose:
- High refractive index: used for optical glass and self-cleaning glass coatings.
- UV Shielding: Architectural and automotive glass.
2. Vanadium oxide (V₂O₅)
- Purpose:
- Thermochromic glass: adjusts light transmittance as temperature changes (smart window).
**Summarize**
- Rare earth compounds dominate the optimization of optical properties (such as coloration, fluorescence, and high refractive index).
- Rare metals (such as indium, and germanium) are mostly used in high-tech fields (conductive coatings, infrared glass).
- Minor Metals (Cobalt, Nickel, Selenium) focus on color control and impurity neutralization.
The application of these compounds enables glass to have diverse functions in fields such as architecture, electronics, optics, and art.
