Question

What is the percentage composition of clay in natural sand?

(a) 22-31%

(b) 3-10%

(c) 5-20%

(d) 18-29%

This question was addressed to me in examination.

I'd like to ask this question from Molding Sands in section Molding and Core Sands of Casting-Forming-Welding I

Answer 1

Right choice is (c) 5-20%

Easy explanation: In natural sands, the percentage composition of clay is approximately 5-20% as the binding material. If the percentage composition is less than that like 3 to 10%, then the binding action will not take place effectively.