Abstract
In corrosion of mullite or zircon by alkali carbonate, alkali sulfate and alkali chloride vapor, respectively, there were difference to corrosion products and its mechanisms.
The difference was raised from the acid radical components of alkali sulfate and alkali chloride. That is, in the first stage the alkali oxide component (Na2O or K2O) reacted with mullite or zircon, and next the acid radical component decomposed these reaction products into glass and the other compounds. Consequently, for example, in corrosion of mullite by sodium carbonate vapor, most corrosion products were carnegieite-sodium aluminate s.s., but in that by sodium sulfate and sodium chloride vapor, respectively, the needlelike crystals of corundum produced remakably with glass.
In the cases of corrosion of mullite by potassium salts vapor and of zircon by sodium salts vapor, there also were similar difference.
Their corrosions by alkali chloride vapor were very analogous to that by alkali sulfate vapor.
