Das Reduktions‐ und Oxydationsgleichgewicht zwischen zwei‐ und dreiwertigem Chrom in flüssigen Kalk‐Kieselsäure‐Chromoxyd‐Schlacken

Abstract

Bisherige Untersuchungen der Chromverteilung zwischen Metall und basischen oder sauren Schlacken zur Ermittlung der Zusammensetzung des Chromoxyds in der Schlacke. Versuche an flüssigen chromhaltigen basischen Kalk‐Kieselsäure‐Schlacken unter Wasserstoff‐Wasserdampf‐Argon‐Atmosphäre. Aufstellung einer Redoxreaktion zwischen zwei‐ und dreiwertigem Chrom. Einfluß von Sauerstoffpartialdruck, Basengrad und Temperatur auf das Verhältnis Cr2+/Cr3+.

Redox Equilibria of Chromium in Calcium Silicate Base Melts

“…Present data together with the data available in the literature. [4][5][6][7][8] but confirm the increase in the Cr 3+ /Cr 2+ ratio with basicity.…”

“…The effect of the total chromium content on the equilibrium of Reaction [4] is not clear. From Figure 3, it is evident that the Cr 6+ /Cr 3+ ratio is higher at the initial content of 1 pct Cr 2 O 3 compared to 3 pct.…”

“…The lower (Cr 6+ /Cr 3+ ) values obtained in the oxygen-rich gases compared to the straight-line relationships are probably caused by the evaporation of Cr 6+ -containing species that occurs in the high-oxygen-pressure range. Figure 4 shows our Cr 3+ /Cr 2+ values together with the data from the literature [4][5][6][7][8] available for CaO-SiO 2 base melts. The total chromium content levels are low and in a range similar to those in our investigation, except for those in the work of Xiao et al, [8] which are somewhat higher.…”

“…This has been previously reported in the literature. [4,7,8] Figure 13 shows the colors in slags with CaO/SiO 2 = 1.10 and 0.10 pct Cr (0.15 pct Cr 2 O 3 (initial)). It is evident that the slag is blue at a low oxygen pressure.…”

“…[1][2][3][4][5][6][7][8] Several studies have been carried out on the redox reactions between Cr 2+ and Cr 3+ . It has been established that, in the low-oxygenpressure range of the slag/metal equilibrium, chromium is mainly divalent.…”