Which among the following are the main ingredients for manufacturing of glass?

The manufacturing of glass involves several key ingredients that serve specific chemical functions. Silica (SiO2), often sourced from quartz sand, acts as the primary glass-forming oxide [2]. Sodium carbonate (soda ash) is a critical fluxing agent that lowers the melting temperature of the silica batch [1][3]. Alumina (Al2O3) is added to improve the chemical durability and hardness of the glass [4]. Borax (sodium borate) is specifically used in the production of borosilicate glass to enhance thermal shock resistance [4]. Additionally, cullets—which are pieces of recycled glass—are integrated into the batch to reduce energy consumption and act as a fluxing agent during the melting process [3][4]. While iron oxide can be used as a colorant, it is not a primary structural ingredient for standard glass, and sodium bicarbonate is generally a precursor or byproduct rather than the primary batch alkali [1][2].

Sources

1. [2] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 13: Types of Rocks & Rock Cycle > 13.5. Some Rock-Forming Minerals > p. 175
2. [1] Science , class X (NCERT 2025 ed.) > Chapter 2: Acids, Bases and Salts > Uses of washing soda > p. 32
3. [3] https://pubs.usgs.gov/periodicals/mcs2025/mcs2025-soda-ash-ver.1.0.pdf
4. [4] https://shura.shu.ac.uk/22180/3/Bingham-MeltingBehaviourOfWasteGlassCullet%28AM%29.pdf