Substitutes for metal in heating ducts

• Publisher: Elsevier Science
• Year: 1943
• Tongue: English
• Weight: 147 KB
• Volume: 235
• Category: Article
• ISSN: 0016-0032
• DOI: 10.1016/s0016-0032(43)90860-9

✦ Synopsis

Studies of the products of reaction between K20.23CAC.-I2SIO2 and CaSO4, and also of those produced when clinker raw mixtures containing both K20 and SO2 are heated, showed that K20 combines preferentially with SO3 to form K~SO4. It was found that any K20 in excess of the amount required by the SO3 in the formation of K2SO4, combined with CaO and SiO2 to form K~O. 23CAO.I2SIO2. No evidence was obtained of any potash compoundsother than K,SO4 and K~O. 23CAO.-I2Si02 in clinkers composed of K20, CaO, A120:~, Fe203, SiO2 and SO3.

At elevated temperatures, the molten K2SO4 appeared to be immiscible with the other liquid phase formed from the components of the clinker and, consequently, seemed to have no effect on the products of crystallization. Upon cooling, K2SO4 crystallized extremely rapidly.

Crystals of K2SO4 were identified in several commercial portland cement clinkers.

No reaction of either K~SO4 or K20.23CaO. I2SIO2 with MgO was observed, which indicates that the presence of MgO does not affect the manner in which K20 is combined in clinker.