Zhu Xiaobo, Ma Chen, Li Wang
College of Chemistry and Chemical Engineering, Henan Polytechnic University, Jiaozuo, Henan 454000, P. R. China.
Henan Key Laboratory of Coal Green Conversion, Henan Polytechnic University, Jiaozuo, Henan 454000, P. R. China.
ACS Omega. 2023 Jul 19;8(30):27127-27138. doi: 10.1021/acsomega.3c02180. eCollection 2023 Aug 1.
A two-stage extraction process was proposed to recover sulfuric acid and vanadium from simulated acid solution and titanium dioxide waste acid (TDWA). Some extractants were compared and studied, in which the enthalpy changes (Δ) of the extraction process and the extracted complex were analyzed by using thermodynamics. The microscopic characteristics of the loaded organic phase were compared and investigated by infrared spectroscopy (FT-IR), where the extraction mechanism was described. The extraction efficiency of sulfuric acid was more than 99% by three-stage countercurrent extraction with 60% triisooctylamine (TEHA) and 35% -pentanol, in which Δ was -61.31 kJ/mol and the extracted complex of HSO·TEHA·2--pentanol was obtained. The extraction efficiency of vanadium was above 98% by using 20% bis-2-ethylhexyl phosphate (P507) and 80% sulfonated kerosene, where Δ was 14.69 kJ/mol and the extracted complex of VO·2A (vanadium as VO and P507 as HA) was obtained. The stripping efficiencies of sulfuric acid and vanadium were more than 90% and 98%, respectively. The extraction effect of used organic phase after regeneration was equivalent to that of the new organic phase with cycle numbers of less than 10. The real waste acid of TDWA was operated to extract and separate sulfuric acid and vanadium with the same parameters, in which the characteristics of high extraction efficiency and good selectivity were obtained. The technique may provide a new thinking for the separation and recovery of valuable components from TDWA.
提出了一种两阶段萃取工艺，用于从模拟酸溶液和二氧化钛废酸（TDWA）中回收硫酸和钒。对一些萃取剂进行了比较和研究，其中利用热力学分析了萃取过程和萃取络合物的焓变（Δ）。通过红外光谱（FT-IR）对负载有机相的微观特征进行了比较和研究，并描述了萃取机理。采用60%三异辛胺（TEHA）和35%正戊醇进行三级逆流萃取，硫酸的萃取效率超过99%，其中Δ为-61.31 kJ/mol，得到了HSO·TEHA·2-正戊醇的萃取络合物。采用20%磷酸二（2-乙基己基）酯（P507）和80%磺化煤油，钒的萃取效率高于98%，其中Δ为14.69 kJ/mol，得到了VO·2A（钒为VO，P507为HA）的萃取络合物。硫酸和钒的反萃效率分别超过90%和98%。再生后使用的有机相的萃取效果与新有机相相当，循环次数小于10次。采用相同参数对TDWA实际废酸进行萃取分离硫酸和钒，具有萃取效率高、选择性好的特点。该技术可为从TDWA中分离回收有价成分提供新思路。
