转炉钒渣氧压酸浸过程V-Fe-H_2O系的电位—pH图  

Potential—pH diagrams for V-Fe-H_2O system during oxygen pressure acid leaching of vanadium-bearing converter slags

作　　者：张廷安[1] 牟望重[1] 豆志河[1] 吕国志[1] 刘燕[1] 

机构地区：[1]东北大学材料与冶金学院多金属共生矿生态化利用教育部重点实验室,沈阳110819

出　　处：《中国有色金属学报》2011年第11期2936-2945,共10页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(51004033;50974035;51074047);国家重点基础研究发展计划资助项目(2007CB613504);国家"十一五"科技支撑计划资助项目(2008BAB34B01)

摘　　要：根据高温水溶液中计算各反应电位、pH及电解质活度因子的经验公式,通过热力学计算,得到氧分压为0.5 MPa、对应质量浓度为0.1mol/kg的离子活度以及温度分别为60、100、150和200℃条件下V-Fe-H2O系的电位—pH图。在pH<2的酸性条件下,V3+、VO2+和VO2+的稳定区一直位于Fe3+和Fe2+的稳定区范围内。随着温度由60℃提高到200℃,可溶性钒铁离子稳定共存区的pH值逐渐降低,氧化还原电位逐渐提高,钒铁尖晶石及氧化物的稳定区变化不大。热力学研究结果表明:采用氧压酸浸工艺能够将转炉渣中的钒充分浸出,但不能通过一步浸出在提钒的同时将钒、铁分离,浸出液还需要进一步净化来生产钒制品。转炉钒渣氧压酸浸的实验结果表明:在浸出温度140℃、氧分压0.5 MPa、粒度0.055～0.075 mm、液固比15-1(体积与质量比)、浸出时间120 min、搅拌速度500 r/min及初酸浓度200 g/L H2SO4的条件下,钒的浸出率为96.87%,铁的浸出率为89.25%,实验结果与热力学计算结果相符合。According to the empirical equations of potential（φ）,pH and the ionic activity factors of various species,the thermodynamics of V-Fe-H2O system at oxygen partial pressure of 0.5 MPa,ionic activity factor of corresponding concentration of 0.1 mol/kg and temperatures of 60,100,150 and 200 ℃ respectively was summarized in the form of（potential—pH）（φ—pH） diagrams.The stable regions of soluble vanadium ions（V3＋,VO2＋ and） contained in the region soluble iron ions（Fe3＋ and Fe2＋） at pH2.With the increase of temperature from 60 ℃ to 200 ℃,the pH values of stable regions of V3＋,VO2＋,,Fe2＋ and Fe3＋ become more negative and the redox potentials get higher.The stable regions of vanadium iron spinel and other oxides are substantially less affected.The thermodynamic calculation results indicate that vanadium can be extracted by oxygen pressure acid leaching method,but iron cannot be separated by one-step leaching process.The leachate needs to be purified to make vanadium products.The experiment results show that leaching rates of vanadium and iron are 96.87% and 89.25%,respectively,at temperature of 140 ℃,oxygen partial pressure of 0.5 MPa,particle size ranging between 0.055 mm and 0.075 mm,ratio of liquid to solid（ratio of volume to mass） of 15-1,leaching time of 120 min,stirring speed of 500 r/min and initial acid concentration of 200 g/L.The experimental results are in good agreement with the results of thermodynamic calculation.

关 键 词：转炉钒渣 氧压酸浸 V-Fe-H2O系 电位—pH图 

分 类 号：TF803.21[冶金工程—有色金属冶金]