Change in Characteristics of Ethyleneglycol during Dissolving Calcium Oxide and its Suppression

Abstract

Changes in solution properties of ethyleneglycol during dissolving calcium oxide were investigated in terms of reinvestigation of the ethyleneglycol method to determine free calcium oxide in steel slags precisely. Dissolution of calcium oxide into ethyleneglycol produced water as a result of chemical reaction between the both entities. As increase in the amounts of calcium oxide dissolved into ethyleneglycol, viscosity of the solution increased with being cloud. Dissolution of calcium oxide from 0.1 g to 0.6 g into 20 mL of ethyleneglycol made the solution a turbid gel. TOF-MS and LC-MS analyses confirmed that oligomerization of ethyleneglycol in the ethyleneglycol solution proceeded to produce many kinds of oligomers of ethyleneglycol. Addition of a partially-halogenated alcohol into the ethyleneglycol solution suppressed change in properties of the solvent, such as increase of viscosity, color development and gelation. Especially, addition of 2,2,2 -trifluoroethanol reduced the variation of analytical values of free calcium oxide contents in the steel slag even though slight decrease in the analytical values.