Determination of divalent and hexavalent chromium in slags

Abstract

A method has been developed for the determination of divalent and hexavalent chromium in iron-free lime-alumina-silica slags. Sparingly soluble slags were dissolved under controlled conditions in dilute hydrochloric acid containing some hydrofluoric acid with excess of iron(III) for slags containing chromium-(II) or excess of iron(II) for slags containing chromium(VI). Subsequently, the amount of iron(II) was determined by potentiometric titration with dichromate solution.

The procedures were tested and found to be reasonably free from systematic errors by comparison with spectrophotometric measurements on chromiumcontaining solutions and on vitreous slags containing chromium(III) and either chromium(II) or chromium(VI).