钒钛磁铁矿提钒尾渣钙化碱浸试验研究

Study on calcified alkaline leaching of vanadium extracton tailings from vanadium titaniummagnetite metallurgy

由于钒钛磁铁矿提钒尾渣中Na2 O含量高,作为炼铁配矿使用时会造成高炉结瘤问题,难以规模化利用。本文针对此问题,以承钢钒钛磁铁矿提钒尾渣为原料,进行了钙化碱浸-偏钒酸铵沉钒试验,目的是对提钒尾脱碱的同时提取其中有价金属钒。试验主要考察了浸出温度、碱浓度、氧化钙添加量和液固比对钠和钒浸出率的影响,结果表明,在浸出温度160℃、碱浓度100 g·L^(-1)、氧化钙添加量15%、液固比6:1、浸出时间60 min的条件下,钒和钠的浸出率分别达到82.25%和85.36%;对含钒碱浸液进行偏钒酸铵沉钒,得到了纯度大于97%的V_(2)O_(5)产品;终渣中Na_(2)O含量小于0.5%,Fe_(2)O_(3)含量达到30.10%,结合承钢高炉的碱金属平衡数据,可满足高炉炼铁配矿使用。本文研究结果可为相关企业钒钛磁铁矿提钒尾渣的规模化利用提供参考。

In view of the problems such as large storage of vanadium extracted tailings,low utilization of valuable components and great harm to the environment,the process of calcification alkaline leaching under normal pressure was adopted to remove the alkali and extract the valuable metal vanadium.The reaction mechanism was studied and the effects of leaching temperature,alkali concentration,calcium oxide addition and liquidsolid ratio on the leaching rate of sodium and vanadium were investigated through single factor experiments.The results showed that the leaching rate of vanadium and sodium reached 82.25%and 85.36%respectively after 60 min leaching under the optimum conditions of 160℃leaching temperature,100 g·L^(-1)alkali concentration,15%CaO addition and 8:1 liquidsolid ratio.At the same time,the vanadium precipitation method with ammonium metavanadate was also used to obtain V_(2)O_(5)products with purity greater than 97%.The analysis of final slag shows that the content of Na_(2)O is less than 0.5%,and combined with the alkali metal balance data of chengsteel blast furnace,it can be used in blast furnace ironmaking and ore blending.