关键词: 四氯化钛精制尾渣, 热力学计算, 锰化焙烧, 钒浸出率, 五氧化二钒

Abstract: In order to investigate feasibility of the extraction and utilization of vanadium resources in the vanadium-containing tailings of titanium tetrachloride refining,on the basis of thermodynamic analysis of vanadium extraction by manganese roasting,the process of pretreatment of titanium tetrachloride refining tailings with water washing,manganese roasting,oxalic acid leaching and vanadium ammonium precipitation was adopted,and the influences of the ratio of liquid to solid in water washing,roasting temperature,and the amount of manganese carbonate added on the composition of physical phase of the clinker and the vanadium leaching rate of the roast were mainly investigated. The results showed that the pretreatment of crude TiCl4 vanadium tailing with water washing can effectively reduce the content of chlorine in the tailing,guarantee the ammonium precipitation of vanadium and improve the grade of vanadium products. Increasing the roasting temperature and the content of manganese carbonate appropriately can help the low valence states vanadium and manganese salts to generate soluble manganese pyrovanadate (Mn2V2O7). However,when the roasting temperature exceeds 850 ℃ and the addition of manganese carbonate greater than 2. 0,it will result in the vanadium-containing phase being encapsulated by silicate and other liquid-phase products, resulting in lower vanadium leaching rate. The optimal conditions in this experiment were water-washing liquid-solid ratio of 10 mL/ g,manganese carbonate addition (in terms of n(MnO) / n(V2O5)) of 2. 0,roasting time of 2 h,roasting temperature of 850 ℃,leaching time of 30 min and leaching temperature of 50 ℃. The leaching rate of vanadium under the above conditions reached 82. 16%,and the leachate could obtain powdered vanadium pentoxide with purity greater than 99% after ammonium salt vanadium precipitation and roasting process. This process realizes the efficient extraction and separation of vanadium from vanadium-containing tailings of titanium tetrachloride refining,and the research results have guiding significance for vanadium extraction from this type of tailings.

Key words: titanium tetrachloride refining tailings,thermodynamics calculations,manganization roasting,vanadium leaching rate,V2O5