Separation and recovery of iron impurities from a complex oxalic acid solution containing vanadium by K3Fe(C2O4)(3)center dot 3H(2)O crystallization
Separation and recovery of iron impurities from a complex oxalic acid solution containing vanadium by K3Fe(C2O4)(3)center dot 3H(2)O crystallization
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K3Fe(C2O4)(3)中心点3H(2)O结晶法从复杂含钒草酸溶液中分离回收铁杂质
DOI：
10.1016/j.seppur.2019.115970
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发表时间：
2020
影响因子：
8.6
通讯作者：
Zheng Qiushi
中科院分区：
文献类型：
--
作者：
Liu Zishuai;Huang Jing;Zhang Yimin;Liu Tao;Hu Pengcheng;Liu Hong;Zheng Qiushi
采用溶剂萃取或离子交换的方法，有效地分离了含钒页岩酸浸出液中的钒和铁；但这些方法均未回收铁，资源综合利用率较低。本文研究了用K3Fe(C2O4)3·3H2O结晶法从含钒的复合草酸溶液中回收铁杂质。在此条件下，铁的回收率为90.7%，V的损失率为1.4%，Al的损失率为5.0%。铁的浓度从结晶前的5366 mg/L下降到结晶后的500 mg/L。结晶产物经再结晶纯化得到纯度为99.0%的K3Fe(C2O4)3·3H2O，并用FT-IR、XRD和SEM对其进行了表征。根据钒和铁在草酸体系中的形态，确定了铁杂质回收的机理。该机制包括五个主要步骤：络合、氧化、配位、成核和晶体生长。K3Fe(C2O4)3·3H2O结晶法从含钒的复合草酸溶液中回收铁杂质是一种新颖、高效的方法，为钒资源的综合利用提供了新的方向。
Vanadium and iron have been effectively separated from the acid leachate of vanadium-bearing shale by solvent extraction or ion exchange; however, in these methods, the iron was not recovered, and the comprehensive utilization rates of the resources were low. In this paper, the recovery of iron impurities from a complex oxalic acid solution containing vanadium via the crystallization of K3Fe(C2O4)3·3H2O was investigated. Using the optimum conditions, 90.7% of the Fe was recovered, and only 1.4% of the V and 5.0% of the Al were lost. The concentration of Fe decreased from 5366 mg/L before crystallization to 500 mg/L after crystallization. The crystallized product was then further purified by recrystallization to obtain K3Fe(C2O4)3·3H2O in 99.0% purity, which was characterized using FT-IR, XRD, and SEM. Based on the speciation of vanadium and iron in the oxalic acid system, the mechanism by which the iron impurities were recovered was determined. The mechanism consisted of five main steps: complexation, oxidization, coordination, nucleation, and crystal growth. The recovery of iron impurities from a complex oxalic acid solution containing vanadium via the crystallization of K3Fe(C2O4)3·3H2O is a novel and efficient method, and this process provides a new direction for the comprehensive utilization of vanadium resources.