Abstract: As chromium content in stainless steel EAF slag is very high, there is a certain leaching risk of Cr6+ from the slag. Silicothermic reduction process was adopted for reducing and detoxifying of liquid layer of the slag during the end of stainless steel smelting in this study. It is found that heavy metal oxide contents of the slag can be effectively reduced, of which Cr2O3 mass fractionis reduced from 6.10 % to 0.79 %, and the maximum detoxification rate can be upto 87.1 %. After detoxification, the phase of CaCrO4, which is the main phase containing Cr6+, was disappeared. According to the leaching toxicity test, the leaching of total Cr was reduced to 0.08 mg/L, while the leaching of Cr6+ was reduced to below 0.01 mg/L, and both of them were obviously far below the national standard's value. Thus, safe discharging and resource utilization of the treated EAF stainless steel slag can be realized.

Key words: EAF stainless steel slag, Cr6+, silicothermic process, detoxification, industrial tes