摘要
对N235萃取除铁进行研究,考察H2O2用量、料液初始pH、萃取剂浓度、萃取剂组成、萃取时间对萃取的影响以及H2SO4浓度、反萃时间对反萃的影响,设计错流萃取过程并绘制反萃平衡等温线,对萃取剂转型条件进行研究。结果表明:H2O3+2用量为理论量3.85倍时可将Fe2+完全氧化成Fe,并采用有机相组成30%(体积分数)N235+10%(体积分数)TBP+磺化煤油作为萃取剂,料液初始pH为0.11,其最佳萃取条件如下:萃取温度25℃,萃取时间2 min,相比O/A为1:1。经过4级错流萃取,其Fe3+萃取率可达96.96%,Cu2+、Co2+、Ni2+损失率分别为3.04%、1.39%和3.84%,有机相负载采用0.3 mol/L硫酸可反萃得到纯度为98.87%的Fe2(SO4)3溶液,其最佳反萃条件为反萃温度25℃,反萃时间6 min,相比O/A=1:1。经两级逆流反萃,Fe3+反萃率达99.12%,反萃铁后的负载酸有机相经Na2CO3中和转型,返回使用。
The extraction of Fe 3＋ by N235 was studied based on the technology gap on the removal of Fe3＋ from iron rich and high acidity sulfuric acid leaching liquid by extraction. The effects of H2O2 dosage, feed initial pH, extractant concentration, extractant composition and extraction time on the extraction, and the effects of H2SO4 concentration and tripping time on the stripping were investigated. The cross current extraction process was designed and the isotherms of stripping were plotted, and the conditions of extractant transformation were researched. The results show that, when 30% （mass fraction） H2O2 dosage is 3.85 times of theoretical one, Fe2＋ can be oxidized into Fe3＋ totally, and with 30% （volume fraction） N235 and10% （volume fraction） TBP in sulphonated kerosene as extractant, the extraction rate of Fe3＋ from the solution with initial pH of 0.11reaches 96.67% in four-stage cross current extraction with O/A ratio of 1：1 （volume ratio of oil phase to aqueous phase） at 25℃ for 2 min, and the loss rate of Cu2＋, Co2＋, Ni2＋ are 3.04%, 1.39%, 3.84%, respectively. The Fe3＋ in loaded organic can be stripped into Fe2（SO4）3 with purity of 98.87% using 0.3 mol/L H2SO4 solution and the stripping rate reaches 99.12% in two-stage counter current stripping with O/A ratio of 1：1 （volume ratio of oil phase to aqueous phase） at 25℃ for 6 min. After stripping, the acid in loaded organic phase can be neutralized using Na2CO3. The organic phase returns to extraction circularly.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2015年第5期1370-1377,共8页
The Chinese Journal of Nonferrous Metals
基金
"十一五"国家科技支撑计划资助项目(2008BAB32B10)
关键词
N235
硫酸浸出液
萃取
除铁
反萃
转型
N235
sulfuric acid leaching liquid
extraction
iron removal
stripping
transformation
