【作者】 李兰杰；

【导师】 娄太平； 张力；

【作者基本信息】 东北大学 ， 化学工艺， 2010， 硕士

【摘要】 针对传统的钒钛磁铁矿提钒工艺(高炉炼铁—铁水吹钒—焙烧提钒)中钒的综合回收率较低,不高于20%,且钒渣经钠化焙烧水浸后的提钒尾渣含钠量高,不利于尾渣的后续处理,另钠化焙烧提钒后的滤液杂质含量高不易得到高品质的V2O5。本文对钒钛磁铁矿精矿钙化焙烧直接提钒进行了研究,该工艺是一种清洁廉价且可以综合利用资源的工艺。通过钒钛磁铁矿精矿的工艺矿物学可知：精矿粒度较细,-200目的精矿体积占43.17%；精矿主要由O、Si、Nb、zr、Ca、Ti、V、Fe等元素组成；各个粒度下的精矿成分相差不大,说明各粒度下的精矿物相比较均一,组成无太大差别；精矿主要由磁铁矿相和钛铁矿相等物相组成。通过磨矿实验,可以得到前30分钟的磨矿效率高。反浮选脱硅的工艺条件为：pH值为6、粒度为-400目、可溶性淀粉200g/t、十二胺用量为900g/t,此时所得的精矿Si02品位为5.64%、V2O5品位为1.23%。通过钒钛磁铁矿精矿与碳酸钙体系的热力学分析及条件实验可知：(1)当焙烧温度在550℃时碳酸钙即发生分解反应,当温度超过700℃时发生(FeO·V2O3)的氧化反应；(2)焙烧体系中可发生固溶反应,致使钒的浸出受到限制,影响了钒的回收率,可通过迅速降温来减少所形成固溶体的影响；(3)对于CaO、SiO2分别大于2%、3%的钒钛磁铁矿精矿钙化焙烧直接提钒效果更好,且选取CaCO3作为焙烧添加剂；(4)焙烧工艺为：CaCO3添加量为10%、焙烧温度为1200℃、焙烧时间为1h时,此时钒的转化率可达到72.1%。通过浸出条件实验可得到：选用H2SO4作为浸出剂,且浸出工艺条件为液固比5：1、H2SO4浓度5%、浸出时间3h、浸出温度90℃,此时V2O5的浸出率为71.4%。更多还原

【Abstract】 The recovery of vanadium was lower and not higher than20%from vanadium slag originate from vanadium titanium magnetite. Tailings containing vanadium after water leaching is high in sodium content, which is unfit to follow-up disposal. At the same time, the filtrate containing some impurities after sodium roasting is difficult to obtain pure V2O5. In this paper, direct extraction of vanadium by calcium roasting from vanadium titanium magnetite concentrate is studied. This process is clean and cheap. Also, it can be in favour of utilization of resources.We can obtain some conclusions by mineral characterization of vanadium titanium magnetite concentrate. First, the concentrate is fine, which contains some grain finer than75micron accounting for43.17%, and it can be researched on ore dressing by grinding slightly. Second, the concentrate is mainly composed of O, Si, Nb, Zr, Ca, Ti, V, Fe and other elements. Third, the composition of concentrate under various sizes is similar. The concentrate is mainly composed of magnetite and ilmenite.The grinding efficient is high in the first30minutes. The suitable condition of anti-flotation desilication is:pH value6, particle size-400mesh, soluble starch200g/t, dodecylamine dosage900g/t. After anti-flotation, teh SiO2content is5.64%.We can obtain some conclusions by thermodynamic analysis and experiment of different conditions between vanadium titanium magnetite concentrate and calcium carbonate. First, the decomposition temperature of calcium carbonate is550℃,(FeO· V2O3) is oxidized when the temperature exceeds700℃. Second, there will be solid solution reaction in this roasting system, which causes restriction in the leaching of vanadium. So the recovery of vanadium is low. In order to reduce the impact of solid solution, we can make rapid cooling. Third, direct extraction of vanadium by calcium roasting from concentrate is better when the concentrate contains CaO, SiO2larger than2%,3%, respectively, and we selected CaCO3as toasting additive. Fourth, the suitable roasting condition is:CaCO3amount10%, toasting temperature1200℃, toasting time lh. And vanadium recovery rate can reach72.1%. Finally, it is in favour of conversion of vanadium that low partial pressure of oxygen in the roasting system.The suitable leaching condition is: H2SO4as the leaching agent is available. The optimum leaching process is liquid-solid5:1, H2SO4concentration5%, leaching time3h, leching temperature90℃, then the leaching rate of V2O5is71.4%.更多还原