Study On Extraction Of Vanadium From Low-grade Vanadium-containing Steel Slag By Waste Acid Extraction

Vanadium-containing steel slag,as an industrial waste produced by vanadium-titanium magnetite extraction of vanadium and steel,at the same time,it is an important secondary resource of vanadium.It must be recycled.Titanium dioxide waste acid as a kind of liquid waste produced from the production of titanium dioxide.Because it contains about 20%sulfuric acid,which is also an important secondary resource.In this paper,Using the method of treating waste with waste,and leaching of vanadium-containing steel slag by titanium white waste acid to recover valuable metals vanadium.Mainly studies three parts:sodium roasting,waste acid leaching and purification of leaching solution during the experiment of titanium acid waste acid leaching of vanadium-containing steel slag.First,a brief study on the kinetic and thermodynamic mechanisms involved in the above three parts is carried out to provide theoretical support for subsequent experimental research.Subsequent studies on the impact of each part on the yield of vanadium led to the following conclusions:?1?The process of leaching vanadium-containing steel slag with waste titanium acid is feasible,and the yield of vanadium from vanadium-containing steel slag to the stripping liquid can reach 68.08%.?2?The optimized parameters for sodium roasting of vanadium-containing steel slag are:particle size of vanadium-containing steel slag 160 mesh,roasting temperature 950?,ratio of sodium salt to vanadium-containing steel slag=15:100.The optimized parameters for leaching of vanadium-containing steel slag from titanium white waste acid are:liquid-solid ratio of 5:1,leaching temperature of 50?,leaching time of 120min,and particle size of material after roasting 100 mesh to 120 mesh.And the optimized parameters of vanadium-containing leachate purification are N235 content 60%,volume ratio V_O:V_A=1:3,and extraction time 6min.?3?Vanadium-containing steel slag is directly leached by untreated titanium white waste acid,and the leaching rate of vanadium can reach 86.18%under the optimized parameters.The main components of the obtained leaching residue are CaSO₄·2H₂O and CaSO₄·0.5H₂O,which can be used as building materials.?4?The vanadium-containing leaching solution is purified by the extraction system of N235+TBP+sulfonated kerosene,and the yield of vanadium is 83.15%under the optimized process parameters.Then choose 0.8mol/L sodium carbonate solution as the stripping agent,the stripping yield of vanadium can reach more than 95%.