【作者】 孙健；

【导师】 朱苗勇；

【作者基本信息】 东北大学 ， 钢铁冶金， 2008， 硕士

【摘要】 本文针对酸性钒钛渣电炉还原工艺,进行了钒在铁液和炉渣间分配的热力学研究。并在热力学研究的基础上进行了钒钛渣还原动力学研究。同时还考察钒钛酸性渣还原过程中物相组成、微观构成的演变,以及V、Ti等元素在渣中赋存状态的变化。本文在对国内外关于含钒钛渣还原反应研究状况进行分析的基础上,使用合成渣模拟金属化球团中的酸性渣,进行了渣中钒氧化物还原的实验研究。实验考察了渣铁比、反应温度、初始V2O5含量、初始TiO2含量、初始FeO含量等因素对钒氧化物还原的影响。实验结果表明：在反应温度为1580℃、渣铁比为1:4、合成渣成分和金属化球团中酸性渣成分相同时,酸性钒钛渣钒氧化物还原反应在70min内进行较快,还原率可达到80%,在120min时基本达到平衡,还原率可达92.9%。温度越高,铁浴量越大及渣中(V2O5)初始含量越大都越有利于钒还原反应,提高了反应速率。渣中(FeO)初始含量和(TiO2)初始含量越高都越不利于钒还原反应的进行,降低了反应速率。通过对不同钒氧化物还原率的炉渣的XRD和SEM分析,发现其主要物相组成为镁铝榴石夹杂少量的透辉石和镁黑钛石夹杂少量氧化铁,钛大量赋存在镁黑钛石中。Ti在反应初期(钒氧化物还原率28.75%-38.34%)大部分赋存于长条状Mg3Al4Ti3O25、MgTi2O5固溶体物相中,少部分分散于硅酸盐相和小块粒状物相中,随着还原反应的进行,Ti逐渐从硅酸盐相中析出并与小块粒状物相结合聚集长大成长条状Mg3Al4Ti3O25、MgTi2O5固溶体物相,并最终以此物相存在。V在反应初期(钒氧化物还原率28.75%-38.34%)主要赋存于小块粒状和长条状含钛物相中与钛紧密共生,随着还原反应的进行,V被逐渐还原进入铁液中,在反应后期(钒氧化物还原率71.41%-76.68%),剩余未被还原的V赋存在硅酸盐相中。更多还原

【Abstract】 Focused on the reduction process of acid vanadium-titanium slag in electric furnace, the basic thermodynamics study on the distribution of vanadium between molten iron and slag and the kinetics of the reduction of acid vanadium-titanium slag were performed in this paper. As well as, the vanadium-titanium slags in the different time of the reduction process were analyzed to investigate the evolution of phases and transformation of existing status of V and Ti in the acid vanadium-titanium slags.Based on reviewing the progress of the fundamental studies on reduction process of vanadium-titanium bearing slag, synthetic slag was used to simulate the acidic slag of the metallic pellet for investigating the reduction reaction of V2O5 in slag in this paper. The influence of factors including temperature, ratio of slags to molten iron, initial content of FeO, V2O5, TiO2 in slags on the reduction of vanadium oxide were studied. The results show that as reaction temperature 1580℃, slag/iron ratio 1/4 and the compasition of synthetic slag same as the composition of the acidic slag of the metallic pellet, the reduction reaction of vanadium oxide is relatively quick within 70min, and the reduction rate is about 80%. While the balance is established in 120min, the reduction rate can reach 92.9%. It’s helpful to the reduction of vanadium oxide and the improvement of the reduction rate that with higher temperature, more molten metal and larger initial content of V2O5 in slags. On the contrary,more initial content of FeO and TiO2 in slags will stunt the reduction and slown the reaction rate.The main phases of slags of different reduction efficiency are Pyrope containing little Diopside and MgTi2O5 containing little FeO, and most Ti are in the MgTi2O5.In the early stages of reaction in which the reduction efficiency is the range of 28.75% and 38.34%, Ti mainly exists in the strip-like phase of Mg3Al4Ti3O25-MgTi2O5 solid solution while the others are dispersed in the phases of silicate and small block. Ti gradually precipitates from the silicate phase and combines the small block-like phase to develop into the strip-like phase of Mg3Al4Ti3O25-MgTi2O5 solid solution then exists finally and steadily in the phase.In the initial stage of the reduction in which the reduction efficiency is in the range of 28.75% and 38.34%, V mainly coexists with Ti in both block-like phase and strip-like phase. With the reacting reduction, V is reduced into the molten iron gradually. In the final stage of reaction in which the reduction efficiency is in the range of 71.41% and 76.68%, the unreacted V is left in the phase of silicate.更多还原