The service life of furnace refractories could be enhanced by coating them with a thin, dense layer of refractory material which can resist adverse furnace environments.

The objective of the present research was to obtain a pure coating of silica, (SiO₂), on the surface of alurnino-silicate refractory bricks. A chemical vapor deposition process utilizing the oxidation of (A) SiCl₄ and (B) SiH₄ was used as a basis of obtaining such a coating. Surface morphology examination, by scanning electron microscopy, of the as-deposited and post fired deposits, showed that firing had the effect of coalescence of the individual spherical particles leading to densification.

Slag corrosion tests of the uncoated and coated refractory bricks using Na₂CO₃·H₂O as the corrosive agent revealed that the former were almost twice as much prone to corrosion attack.