Reduction of chromium oxides in stainless steel dust

Abstract

The recovery of metal oxides from stainless steel dust using C (graphite), SiFe, and Al as reductants was investigated under various conditions. The apparent distribution ratio of Cr ( m/s Cr L ′ ) in the recovered metal and residual slag phases was defined as the major performance metric. The results show that the recovery ratio of metals increases as the ratio of CaO:SiO 2 by mass in the residual slag increases to 1.17. The residual content of metals in the slag decreases as the Al 2 O 3 content of the slag is increased from approximately 8wt% to 10wt%. The recovery ratio of Cr increases with increasing m/s Cr L ′ , and a linear relationship between m/s Cr L ′ and the activity coefficient ratio of CrO in the slag and the recovered metal phase is observed. The combination of C and SiFe or Al as the reducing agents reveals that Si is the more effective coreductant. Nomenclature B:Basicity of the residual slag, which is defined as B = [(%CaO) + (%MgO)]/[ (%Al 2 O 3 ) + (%SiO 2 )]; :

Effects of Fe2O3 on Reduction Process of Cr-Containing Solid Waste Self-Reduction Briquette and Relevant Mechanism

“…Fully recycling chromium in these solid wastes will not only improve enterprises' economic efficiency, but also reduce the risk of heavy metal pollution caused by Cr in solid wastes after being leached in the natural acidic or alkaline environment [6]. In all of Cr-containing solid wastes treatment technologies, high-temperature reduction technology using carbonaceous reductants has been paid extensive attention due to its unique characteristics compatible with metallurgical enterprises [5,[7][8][9][10]. Due to its excellent reactivity, self-reduction briquette bearing C was mostly adopted [11][12][13][14].…”

Valuable Recovery Technology and Resource Utilization of Chromium-Containing Metallurgical Dust and Slag: A Review

“…Compared to fine dust, coarse dust has a particle size of approximately 80 µm, with a much The main elements contained in stainless steel dust are Mg, Si, Cr, Fe, Zn, and Ni. Table 1 lists the chemical composition and phases of typical stainless steel dust [7,18,[29][30][31][32][33][34][35][36][37][38][39][40][41][42]. As can be seen from Table 1, it is evident that Fe is the predominant element, with a content ranging from 14.77% to 53.50%.…”

“…Chemical composition and phase of typical stainless steel dust[7,18,[29][30][31][32][33][34][35][36][37][38][39][40][41][42][43].…”

Activity of Chromium Oxide in CaO–SiO₂–MgO–Al₂O₃–MnO–CaF₂–CrO<i>_x</i> Slag for Chromium Reducing Process

“…At present, adding reductant to reduce the chromium oxide in slag is widely employed as an effective method to achieve the demand of chromium recovery [12][13][14][15] . In order to improve the efficiency of this chromium reduction process, reliable thermodynamic data for chromium oxide activities in the slag are necessary.…”