Question

__________ is refractory sand that can be molded to intricate shape.

(a) Quartz

(b) Olivine

(c) Bentonite

(d) Clays

The question was posed to me by my school principal while I was bunking the class.

The above asked question is from Types of Binders in the Moulding Sand, Types of Base Sand topic in chapter Casting Processes of Foundry and Forging

Answer 1

The correct answer is (b) Olivine

To elaborate: Olivine is refractory sand. When packed as the mold cavity, they remain sufficiently porous or permeable to give vents to the mould gases to escape out. Hence they are chemically immune and can be molded in intricate shapes.