Which is not a natural insulating material ?

Related Mcqs:

Porosity is induced in insulating refractories by adding________________?

A. Powdered naphthalene B. Ammonium chloride/sulphate C. Calcium phosphate D. All A., B. and C....

Chromite refractories_____________________?

A. Are bonded with lime and clay B. (Free from silica) have better thermal fatigue resistance than silica and magnesite refractories. C. Are resistant to basic slag D. All A., B. and C....

Refractories are dried in the _______________?

A. Rotary kilns B. Tunnel kilns C. Sun D. None of these...

Pick out the wrong statement ?

A. Electrical conductivity of refractory is not important, when these are to be used in electrical furnaces B. Graphite and metals are the good electrical conductor among the refractories and others are all electrical insulators C. Refractories used for lining electrical furnaces should ordinarily have very low electrical conductivity D. Electrical conductivity of porous refractory … Pick out the wrong statement ?Read More...

______________ bricks should not be used in oxidising atmosphere?

A. Tar dolomite B. Carbon C. Silica D. Fireclay...