Distribution behavior of Cr between high-carbon ferrochrome alloy and Al₂O₃-SiO₂-MgO-CaO-CrO_x slag

Abstract

The high-carbon ferrochrome is an essential raw material for producing stainless steel, and the demand of it increases with the increase of stainless steel. So increasing Cr recovery rate from chromite is essential for lower costs and higher economic benefits in high-carbon ferrochrome production process. This study calculated the activity of CrO_x in slag and investigated the distribution behavior of Cr between slag and alloy. The ω(MgO)/ω(Al₂O₃) was 1.0, and the w(CaO)/w(SiO₂) was from 0.2 to 0.6 in this study. The calculation and experimental results showed that the main phases of the slag were chrome-containing spinel, magnesium-aluminum spinel, olivine and melilite. The content of spinel in slag decreased with the increasing w(CaO)/w(SiO₂), and the w(CrO_x) in spinel also reduced, but the content of melilite increased. The distribution ratio of Cr between slag and alloy decreased with the increase of slag basicity at 1600 °C, meansning that increasing the w(CaO)/w(SiO₂) of slag can improve the recovery of Cr in chromite smelting process.

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