【作者】 刘建兴；

【导师】 薛向欣；

【作者基本信息】 东北大学 ， 冶金工程， 2013， 硕士

【摘要】 高铬型钒钛磁铁矿是一种含铁、钒、钛、铬等多种元素共生的复合矿,具有极高的综合利用价值。钒钛为世界上公认的战略性金属,广泛的应用于航天航空、海洋、医药、通讯等领域；我国铬资源将面临枯竭,需要急需解决我国对铬资源长期需求问题。目前,高炉冶炼仍是实现钒钛磁铁矿综合利用的重要手段和途径。国内外尚无针对高炉冶炼高铬型钒钛磁铁矿相关的研究。而研究表明普通钒钛矿的钒钛氧化物的还原发生在高炉的软熔滴落带。因此本文探讨了软熔滴落带高铬钒钛磁铁矿有价组元的迁移机理。为此,本研究首先摸索了配加高铬型钒钛磁铁矿的球团矿制备过程；其次研究了配加高铬型钒钛磁铁矿的球团矿、烧结矿以及两者组成的球比为33.65%混合炉料结构的软熔滴落特性；在此基础上,探讨了球团矿和混合炉料在软熔滴落带有价组元迁移机理以及其在滴落金属铁中的含量和在未滴落物中的物相组成。最后从热力学角度对有价组元迁移过程进行了理论分析。本研究得出以下结论：(1)配加40%高铬钒钛磁铁矿的氧化球团在1275℃焙烧20分钟后得到的成品球抗压强度达到2582N/个,满足球团作为高炉炉料的要求。(2) 综合考虑软熔滴落带的位置分布和炉料的透气性阻力两个指标,球比为33.65%的混合炉料结构的软熔滴落特性为最佳。其开始熔化温度为1245.1℃,滴落温度为1376.4℃,最大压差为15527Pa。(3)球团矿和混合炉料的有价组元在软熔滴落带的迁移机理基本一致。铁组元迁移机理为：Fe203→Fe304→FeO→Fe,同时生成的FeO会和SiO2生成2FeO·SiO2；钛组元的迁移机理：Fe2O3·3TiO2→2FeO·Ti02→FeO·Ti02→Ti(00.19C0.53N0.32)→Ti(C0.7N0.3) →Ti(C,N)→[Ti]；钒组元的迁移机理：V2O3→VN→VC→[V]；铬组元的迁移机理：(Fe0.6Cr0.4)203→FeCr2O4→[Cr].(4)通过热力学计算表明钛氧化物还原过程由Fe2Ti05→Fe2Ti04→FeTi03还原过程非常容易,同时理论上表明在还原过程中会出现Ti3O5和TiC、TiN:钒氧化物还原过程中在理论上按VN、VC、VO的顺序出现；铬氧化物能还原成的Cr并且与Fe形成连续的固溶体；铁氧化物在还原过程符合逐级转变原则。更多还原

【Abstract】 The high chromia vanadium-titanium magnetite is a symbiotic compound mineral including Fe, V, Ti, Cr and other elements, which has a very high comprehensive utilization value. Vanadium and titanium are recognized as the world’s strategic metals, widely used in aerospace, marine, medical, telecommunications and other fields. At the same time, China will face the depletion of chromium resources. So it is urgently needed to solve the issue of our long-term demand for chromium resources. Smelting vanadium-titanium magnetite by blast furnace is still an important mean and pathway to achieve the comprehensive utilization. However, there are no relative researches about smelting high chromia vanadium-titanium magnetite by blast furnace in home and abroad. The relevant studies show that the reduction reactions of vanadium and titanium oxide occur in the cohesive zone of BF. Therefore, it is necessary to ascertain the transfer mechanism of valuable components in cohesive zone when smelting high chromia vanadium-titanium magnetite in the condition of BF process.Therefore, this study explored the preparation process of oxide pellet added 40% high chromia vanadium-titanium magnetite firstly. Second the cohesive dropping characteristics of three different burdens structures including pellet, sinter and mixed burden that the ratio of pellet is 33.65%were investigated. Based on the above, the migration mechanism of valuable components in cohesive dropping zone and the contents of valuable components in dropping iron as well as the phase compositions in not dropping substance were researched. Finally, the migration mechanism of valuable components was analyzed in theory from the view of thermodynamic.By this study, the following conclusions can be gained:(1) The pellet added 40% high chromia vanadium-titanium magnetite was roasted at 1275 ℃ with 20 minutes. Its crushing strength is 2582 N, which can meet the quality requirements for blast furnace production.(2) Considering the two indicators of distribution of the cohesive dropping zone and permeability resistance, the cohesive dropping characteristics of mixed burden structure are the best. It starting melting temperature, dropping temperature and maximum pressure were 1245.1℃,1376.4℃, and 15527 Pa.(3) The valuable components migration mechanism of pellet and mixed burden in cohesive dropping zone is consistent. The migration process of iron is Fe2O3→Fe3O4→FeO →Fe, at the same time, the generated FeO will generate 2FeOSiO2 with SiO2; The migration process of titanium is Fe2O3-3TiO2→ 2FeOTiO2→FeO·TiO2→Ti(O0.19C0.53N0.32)→. Ti(Co.7No.3)→Ti(C,N)→[Ti]; The migration process of vanadium is V2O3→VN,VC→[V]; The migration process of chromium is (Feo.6Cro.4)2O3→FeCr2O→[Cr].(4) By thermodynamic calculations show that titanium oxide reduction process will produce Ti3O5,TiC and TiN and the reduction process of Fe2TiO5→Fe2TiO4→FeTiO3 is easy; Vanadium oxide reduction process will be VN →VC →VO; Chromium oxide can be reduced to Cr which will form a continuous solid solution with liquid iron; Ferric oxides are deoxidized according to the theory of Gradual Deoxidizing.更多还原