The most widely used glasses, by far, are oxide glasses, mainly formed from SiO2, B2O3, P2O5, As2O3, Sb2O3, GeO2, TeO2, Al2O3, alkali or alkaline earth oxides, etc.

Glass is made from natural and abundant raw materials (sand, soda ash and limestone) that are melted at very high temperature to form a new material: glass.

In a commercial glass plant, sand is mixed with waste glass (from recycling collections), soda ash (sodium carbonate), and limestone (calcium carbonate) and heated in a furnace. The limestone is added to stop that happening. The end-product is called soda-lime-silica glass.

sand
The primary raw materials in glass are sand, soda, limestone, clarifying agents, coloring and glistening glass. Glass sand is about ¾th of the entire glass composition. How is Glass Produced?

Raw Materials Used in Glass Manufacturing Process

Manufacture of glass requires a large number of raw materials such as silica sand, coal and chemicals. Silica sand is the most important raw material. Sands of the degree of purity requisite for glass-making are found at several places in India. Coal is largely obtained from West Bengal and Jharkhand.

The amorphous structure of glassy silica (SiO2) in two dimensions.

The most significant use for gypsum is for wallboard and plaster products. A small amount of very pure gypsum is used in glass making and other specialized industrial applications.

soda-lime glass, lead glass and borosilicate glass. These three types of glass make up around 95 percent of the cullet glass used in the production process. The remaining 5 percent of glass is special-purpose glass.

Glass production involves two main methods – the float glass process that produces sheet glass, and glassblowing that produces bottles and other containers. It has been done in a variety of ways during the history of glass.

The fine raw materials are subsequently mixed with each other to achieve a homogenous composition and then they are transferred into the melting furnace. Melting of raw materials at high temperature to form a molten glass is the central phase in the manufacturing of glass.

This process consists in simply pulling the molten glass either by hand or by mechanical equipment. An iron bar is dipped sideways in the molten mass of glass. It is lifted up horizontally and in doing so, it catches up a sheet of molten glass.

Float glass is a sheet of glass made by floating molten glass on a bed of molten metal, typically tin, although lead and various low melting point alloys were used in the past. This method gives the sheet uniform thickness and very flat surfaces. Modern windows are made from float glass.

1 Sand or Silica. The main ingredient of glass making is Silica, which as a very high melting point of over 2,000 deg C. 2 Sodium Carbonate. Sodium Carbonate lowers the melting point of Silica to about 1,000 deg C and is therefore added to make the process more efficient. 3 Lime or Calcium Oxide. 4 Other Additives. 5 Colour Additives.