The following statements about silicon materials are incorrect: (a) Traditional silicate ceramics are mainly made of clay sintered at high temperature; And (b) silica.

A. Ceramics are made of clay as the main raw material and sintered at high temperature, so A is correct;

B. The composition of optical fiber is silicon dioxide, which can be used to make optical fiber, so B is correct;

C. According to the composition of glass, the raw materials for making glass are mainly soda ash, limestone and seasonable, so c is correct;

D. Hydrochloric acid does not react with silicon. Generally, monocrystalline silicon is polished with a mixed solution of HF and HNO3, so D is wrong.

So choose D.