Refractory Technology MCQ Questions & Answers | Chemical Engineering

A. Very high thermal conductivity

B. High co-efficient of expansion upto this temperature

C. High thermal diffusivity

D. Low refractoriness

A. Increases

B. Decreases

C. Remains constant

D. May increase or decrease ; depends on its alumina content

A. Less shrinkage in heating, decreased apparent porosity & increased specific gravity

B. High strength & thermal spalling resistance

C. Less addition of water to get a workable plasticity & lesser time required for drying the raw refractories and hence increased rate of production

D. All of the above

A. Are stored under controlled temperature & humidity to avoid hydration

B. Are used in outer lining of L.D. converters

C. Have poorer hydration resistance than pitch bonded bricks

D. All of the above

A. Basic

B. Neutral

C. High alumina

D. Insulating

A. Quartz

B. Cristobalite

C. Tridymite

D. All of the above

A. Thoria Has high fusion temperature (> 3000°C) but poor resistance to thermal shock

B. Thoria Has high resistance to basic slags

C. Which is expensive & radioactive, is used in crucibles for melting high purity metals

D. All of the above

A. Depends on the nature of slag & refractory

B. Decreases at higher temperature

C. Decreases, if defective joints & cracks exist in the refractory

D. All of the above

A. Al₂O₃

B. CaO

C. SiO₂

D. All of the above

A. Resistance to slag attack increases

B. Spalling resistance reduces

C. Both A & B

D. Neither A nor B