Question

How much silica do silica refractories usually contain?

(a) 95 – 97%

(b) 0.2 – 1.0%

(c) 1.8 – 3.5%

(d) 0.3 – 0.9%

I had been asked this question during a job interview.

I would like to ask this question from Refractory Materials, Superalloys in section Refractories & Dielectric Materials of Engineering Material & Metallurgy

Answer 1

The correct choice is (a) 95 – 97%

Explanation: Silica is a common type of acid refractory material containing high amounts of silica and low amount of alumina. It contains about 95 – 97% of SiO2, 0.2 – 1.0% of Al2O3, 1.8 – 3.5% of CaO, and 0.3 – 0.9% of Fe2O3. It has an approximate fusion temperature of 1700^oC.