Thermodynamic Properties of Chromium Bearing Slags and Minerals. A Review

摘要

In this report, the thermodynamic properties of chromium bearing slags andminerals were reviewed based on the available information in the literature. It includes the analyzing methods for oxidation state of chromium in slags, oxidation state of chromium and activities of chromium oxides in slags and minerals. The phase diagrams of chromium oxide systems and chromium distribution between slag and metal phases are also covered in this review. Concerning the analyzing methods, it was found that most of the available approaches are limited to iron free slag systems and the sample preparation is very sensitive to the analyzing results. In silicate slags under reducing atmosphere, divalent and trivalent chromium co-exist in the slags. It is agreed that the fraction or divalent chromium to total chromium increases with higher temperature, lower slag basicity and oxygen potential. For the slags under oxidizing atmosphere, trivalent, pentavalent and hexavalent states were reported to be stable.