Question

________________ is the binder used in the CO2 moulding.

(a) Silica sand

(b) Sodium Silicate

(c) Sodium Carbonate

(d) Alumina

This question was addressed to me by my school teacher while I was bunking the class.

My doubt stems from Carbon Dioxide Mould in portion Moulding Machines & Special Moulding Processes of Foundry and Forging

Answer 1

The correct answer is (b) Sodium Silicate

To elaborate: The CO2 moulding is an extremely simple procedure. The highly flow able mixture of pure dry silica and sodium silicate binder is rammed or blown into the mould or cores box. Due to sodium silicates excellent binding properties with silica sand it is used as binders.