含NaOH碱性钒渣提取液中铬的选择性吸附实验研究  

Experimental Study on Selective Adsorption of Cr from NaOH-containing Basic Extracting Solution of Vanadium Slag

作　　者：薛渊 陈杨 季益龙 沈少波 

机构地区：[1]北京科技大学冶金与生态工程学院稀贵金属绿色回收与提取北京市重点实验室,北京100083

出　　处：《稀有金属与硬质合金》2018年第1期14-20,共7页Rare Metals and Cemented Carbides

摘　　要：对钒渣进行加NaOH造块、焙烧、水浸以及过滤等处理,得到pH=13.1的强碱性钒渣提取液。将带有铵基[—CH2NH(CH2CH2NH)nH]+官能团的弱碱性阴离子交换树脂B直接加入钒渣提取液中进行选择性吸附实验,研究提取液中铬离子的吸附行为。结果表明,在20、30、40℃吸附温度下,Cr吸附平衡时间分别为24、7、7h。当吸附温度由20℃升高到30℃时,铬离子吸附量相应地急剧增加,优化的吸附温度为30℃,此时Cr平衡吸附量为217mg/g树脂。铬离子吸附遵循准一级吸附动力学模型,当吸附温度由20℃升高到30℃时,铬离子吸附速率相应提高了2倍左右。铬离子在树脂孔道内的内扩散是吸附速率的控制环节;铬离子初始浓度越大,其吸附量越大。热力学上,铬离子吸附同时符合Langmuir模型、Freundlich模型和DKR模型,但最接近Freundlich模型。由DKR模型得到,在20、30、40℃吸附温度下,铬离子的表观吸附能分别为5 000、7 071、7 071J/mol。Vanadium slag was subjected to pelleting with NaOH,roasting,leaching with water and filtering to obtain strongly basic vanadium slag extracting solution with the pH value of 13.1.A weakly basic anionic exchange resin B containing amino functional group[-CH2 NH（CH2 CH2 NH）nH]＋was directly added into the extracting solution for selective adsorption experiments.The adsorption behavior of Cr ions in the extracting solution was studied.The results show that when the absorption temperature is 20℃,30℃and 40℃,Cr adsorption equilibrium time is 24 h,7 hand 7 h,respectively.When the adsorption temperature is raised from 20 ℃to 30 ℃,Cr adsorption amount dramatically increases.The optimal adsorption temperature is 30℃and Cr equilibrium adsorption amount is 217 mg/g in this case.Cr ion adsorption follows pseudo-first-order adsorption kinetic model.When the adsorption temperature is raised from 20 ℃to 30 ℃,Cr adsorption rate increases by about 2 times.The internal diffusion of Cr ions in the resin pores is the controlling step of adsorption rate.Cr adsorption amount increases with the initial Cr concentration increasing.Thermodynamically,Cr ion adsorption is consistent with the Langmuir model,the Freundlich model and the DKR model,but it is closest to the Freundlich model.Based on the DKR model,the apparent adsorption energy of Cr ions is 5 000 J/mol,7 071 J/mol and 7 071 J/mol,respectively at the absorption temperature of 20 ℃,30 ℃ and 40 ℃.

关 键 词：碱性钒渣提取液 加NaOH造块 铬离子吸附 弱碱性阴离子交换树脂 吸附动力学 吸附热力学 

分 类 号：TF804.3[冶金工程—有色金属冶金]