Materials Science

Step 1: Understanding silica refractories.
Silica refractories are primarily composed of silica (SiO ). Their chemical behavior depends on the nature of silica, which reacts readily with basic slags but remains stable in acidic environments.
Step 2: Classification of refractories.
Refractories are classified into acidic, basic, and neutral types based on their chemical resistance to slags. Silica-based materials fall under acidic refractories because they resist acidic slags but react with basic slags.
Step 3: Analysis of other options.
(B) Basic refractories: These include magnesia and dolomite refractories.
(C) Neutral refractories: Examples include alumina and chromite.
(D) Magnesia refractories: These are basic refractories, not silica-based.
Step 4: Conclusion.
Therefore, silica refractories are correctly known as acid refractories.