Efficient Separation and Recovery of Vanadium, Titanium, Iron, Magnesium, and Synthesizing Anhydrite from Steel Slag

The dumping of a large amount of steel slag not only wastes metal resources, but pollutes the ecological environment. In this study, a method for recovery of vanadium, titanium, iron, magnesium, and synthesizing anhydrite from steel slag is proposed. The leaching efficiency of V, Ti, Fe, and Mg was 99.42%, 99.36%, 99.89%, and 99.95%, respectively, under a H2SO4 concentration of 30%, a leaching temperature of 70 degrees C, and a leaching time of 90 min. At the same time, anhydrite with a purity of 93.09% was obtained. The leachate can be reused twice, and the obtained gypsum was calcined at 200celcius to obtain anhydrite. 99.45% V and 99.98% Ti were extracted in leachate by two-stage countercurrent extraction with 25% P507 at an equilibrium pH of 1.6. 99.86% of the Fe in the raffinate can be recovered by the precipitation method. Subsequently, the 0.45 mol/L H2C2O4 was used to precipitate Mg as MgC2O4 center dot 2H(2)O under the pH value of 5.5, indicating that the precipitation efficiency of Mg can reach 98.39%. The present process can effectively separate vanadium, titanium, iron, and magnesium and synthesize anhydrite products realizing the cleaner utilization of steel slag