During production of glass, the sand melts at 1700oC. Which of the following should be added to decrease its melting at 850oC?
The correct option is B Discarded glass
Primary consistuents of glass production are sand (silica), soda ash (sodium carbonate), limestone (calcium carbonate). All these are mixed and heated to obtain a molten mass.
Sand (SiO2) melts at 1700o C, which requires a large amount of energy. So, in order to decrease the temperature, pieces of discarded glass, called cullet, are added.