表面浸润强化转炉钒渣中钒和铬的浸出

摘要

Technology intensified with surface wettability was introduced to leach vanadium and chromium from converter vanadium slag without roasting. Parameters affecting the leaching efficiency of vanadium and chromium were investigated: sulfuric acid concentration, MnO2-to-slag mass ratio, liquid-to-solid ratio, leaching time, leaching temperature, and sodium dodecyl sulfate (SDS)-to-slag mass ratio. The leaching efficiencies of vanadium and chromium were 33.46 % and 20.02 % higher in the presence of MnO2and SDS, respectively, compared to the control. The leaching efficiencies of vanadium and chromium were 68.93 % and 30.74 %, respectively, under the optimum conditions: sulfuric acid concentration 40 wt%, MnO2-to-slag mass ratio 10.0 wt%, liquid-to-solid ratio 5:1 mL/g; 12 h;90 °C; and SDS-to-slag mass ratio 0.25 wt%. The analysis of the reaction mechanism in the leaching process indicates that MnO2combined with protons (H+) could oxidize low-valent vanadium and chromium; SDS could change the chemical behavior and decrease the surface tension of the aqueous solution to favor MnO2oxidization.%介绍一种从转炉钒渣中提取钒和铬的表面浸润强化浸出技术,考察硫酸浓度、二氧化锰(MnO2)的添加量、液固比、浸出时间、浸出温度以及十二烷基硫酸钠(SDS)的添加量对钒和铬浸出率的影响. 结果表明:在浸出过程中添加MnO2和SDS,钒和铬的浸出率比未添加时分别高33.46% 和20.02%,在硫酸浓度40 wt%、反应时间 2.0 h、液固比 5:1 mL/g、反应温度90 °C、MnO2添加量为10.0 wt%以及SDS的添加量0.25 wt%时,钒和铬的浸出率分别为68.93%和30.74%.浸出过程反应机理表明, MnO2协同H+离子可以氧化低价钒和铬,SDS能改变溶液表面化学行为,降低溶液表面张力,有利于MnO2的氧化.