Skip to main content
NCBI home page
ACS Omega logoLink to ACS Omega
. 2021 Oct 7;6(41):27478–27484. doi: 10.1021/acsomega.1c04397

Novel Technology for Vanadium and Chromium Extraction with KMnO4 in an Alkaline Medium

Hao Peng †,*, Jing Guo †, Huisheng Huang †, Bing Li †, Xingran Zhang ‡,*
PMCID: PMC8529671  PMID: 34693168

Abstract

graphic file with name ao1c04397_0012.jpg

This paper focused on the oxidation–alkaline extraction process of vanadium–chromium–reducing residue. The affected parameters including reaction temperature, KMnO4 dosage, reaction time, NaOH dosage, and liquid-to-solid ratio on the extraction process were investigated. The E–pH diagram and the thermodynamic analysis indicated that KMnO4 was suitable for the oxidation of low-valence vanadium and chromium. Vanadium (97.24%) and chromium (56.20%) were extracted under the following optimal reaction conditions: reaction temperature of 90 °C, reaction time of 90 min, dosage of KMnO4 at m(KMnO4)/m(residue) = 0.40, dosage of NaOH at m(NaOH)/m(residue) = 0.30, and liquid-to-solid ratio at 5:1 mL/g. The extraction process of vanadium was controlled by the reactant through the solid product layer and the extraction kinetics behavior fitted well with the shrink core model with an Ea of 15.37 kJ/mol. At the same time, the surface chemical reaction was the controlling step for chromium extraction, which was difficult with an Ea of 39.78 kJ/mol.

Introduction

As important national strategy sources, vanadium, chromium, and their compounds were widely used in iron steel, catalysts, and the petrochemical industry because of their excellent physicochemical properties; therefore, vanadium was called the “vitamin of modern industry”.1−6 A so-called vanadium–chromium–reducing residue (VCRR), which is a solid waste from vanadium industries, has attracted much attention in recent years.7−10 It is an important vanadium–chromium source because it contains large amounts of low-valence vanadium and chromium. Every year, over 500 000 tons of VCRR is produced in China.11−14 The inefficient VCRR management has caused significant environmental pollution and waste of the vanadium–chromium source. Therefore, some proper treatment technologies are urgently required.

Vanadium and chromium are placed near tin in the Periodic Table; thus, they have similar chemical and physical properties and commonly exist in co-compounds, making their separation and recovery hard.3,15−19 Many hydrometallurgical methods have been developed for the extraction and recovery of vanadium and chromium. Direct alkaline extraction,20 electro-oxidation–alkaline extraction,21,22 and oxidation–extraction associated with MnO2, H2O2, KClO3, and K2Cr2O7 offered highly selective extraction efficiency for vanadium,10,23−25 while chromium could be hardly extracted. To extract vanadium and chromium at the same time, some acidic extraction processes were investigated.26−28 As the high-valence vanadium recovery was more preferable, selective oxidation technology was applied to separate and recover vanadium and chromium. Wang introduced MnO2 to oxidize vanadium(III) and finally achieved 86.5% recovery efficiency for vanadium in total, which was lower than most industrial practices.14 Peng also investigated the oxidation–acidic extraction process with MnO2. Vanadium (97.93%) and almost all chromium were extracted out.8 However, the separation and recovery of vanadium and chromium in an acidic solution are also urgent problems. Some technologies associated with ion exchange and solvent extraction for the simultaneous recovery of vanadium and chromium could achieve great performance, but high costs and complex operations still exist.29−33

In this paper, a strong oxidant named KMnO4 was applied to enhance the extraction process of VCRR in an alkaline medium. The effect of reaction time, KMnO4 dosage, reaction temperature, NaOH dosage, and liquid-to-solid ratio on the extraction process were investigated. The extraction kinetics behaviors and the optimal extraction conditions were also examined.

Results and Discussion

Thermodynamic Analysis

The main reactions during the extraction process were between the low-valence vanadium, low-valence chromium, and KMnO4 in concentrated NaOH solution (eqs 1–3). The standard Gibbs energy (ΔGTθ) of these reaction equations at selected reaction temperatures could be calculated with ΔfH298, S298θ and Cp at 25 °C (eqs 4–6).34,35

graphic file with name ao1c04397_m001.jpg 1
graphic file with name ao1c04397_m002.jpg 2
graphic file with name ao1c04397_m003.jpg 3
graphic file with name ao1c04397_m004.jpg 4
graphic file with name ao1c04397_m005.jpg 5
graphic file with name ao1c04397_m006.jpg 6

Equation (7) was obtained by merging eqs 4–6.

graphic file with name ao1c04397_m007.jpg 7

Also, ΔCp was calculated as eq 8.

graphic file with name ao1c04397_m008.jpg 8

Then, ΔGTθ was calculated as eq 9.

graphic file with name ao1c04397_m009.jpg 9

Integrate.

graphic file with name ao1c04397_m010.jpg 10

The ΔfH298θ, ΔST, a, b, c, and d in eq 10 could be obtained from the handbook.3434

The results in Figure 1 display that ΔG of eqs 1–3, which occurred during the extraction process, was negative at selective reaction temperatures. It could be concluded that the extraction process was feasible thermodynamically. The oxidation of low-valence chromium was harder than that of low-valence vanadium as ΔG of eq 3 was much larger than that in eqs 1 and 2. In other words, vanadium was easy to extract than chromium at selected reaction temperatures.

Figure 1.

Figure 1

Open in a new tab

Relationship between ΔG and temperature of main reactions.

Extraction Process

Effect of KMnO4 Dosage

The E–pH diagram of the Cr–V–Mn system shown in Figure 2 is calculated and simulated by HSC Chemistry software. It could be seen that the potential of MnO4– was higher than Cr(III/VI) and V(III/IV/V), which was consistent with the results analyzed in the book34 (E0(MnO4–/MnO2) = 1.68 V, E0(CrO42–/Cr3+) = 0.13 V, E0(VO2+/V3+) = 0.668 V and E0(VO2+/VO2+) = 0.991 V). Therefore, KMnO4 was suitable for the oxidation of Cr(III) and V(III/IV) in the extraction process. The effect of KMnO4 dosage on the extraction process was investigated while keeping the reaction temperature of 90 °C, liquid-to-solid ratio of 5:1 mL/g, reaction time at 90 min, and m(NaOH)/m(residue) = 0.30. The KMnO4 dosage was set as m(KMnO4)/m(residue) = 0.00, 0.05, 0.10, 0.20, 0.30, and 0.40. The extraction efficiencies for vanadium and chromium are displayed in Figure 3.

Figure 2.

Figure 2

Open in a new tab

E–pH diagram of the vanadium–chromium–manganese system at 25 °C.

Figure 3.

Figure 3

Open in a new tab

Effect of KMnO4 dosage on the extraction efficiencies for vanadium and chromium.

The results in Figure 3 display that only 23.46% vanadium and 3.43% chromium could be directly extracted in an alkaline medium without KMnO4 as vanadium and chromium exist in the low-valence state, which led to low solubility in the alkaline medium. The addition of KMnO4 could significantly enhance the extraction process and improve the extraction efficiencies for vanadium and chromium. The extraction efficiency increased sharply at low KMnO4 dosage and then smoothly. Vanadium (97.24%) and chromium (56.20%) were extracted at m(KMnO4)/m(residue) = 0.4, and the results were consistent with the thermodynamic analysis. As the increasing trend of extraction efficiency was approaching smooth, continue increased KMnO4 dosage had no big increase for the increase in extraction efficiency. Thus, the KMnO4 dosage of m(KMnO4)/m(residue) = 0.4 was selected as the optimal condition for further experiments. However, further treatment was needed for the extraction residue as nearly half of chromium was retained in the residue. This will be investigated in our future studies.

Effect of NaOH Dosage

Although acidic extraction of vanadium and chromium was more efficient than alkaline extraction, the filtration process was hard to achieve due to the high content of Si. Thus, alkaline extraction was selected in this paper. The effect of the NaOH dosage on the extraction process was studied while the other reaction conditions were kept constant: reaction time of 90 min, liquid-to-solid ratio of 5:1 mL/g, m(KMnO4)/m(residue) = 0.40, and reaction temperature of 90 °C. The NaOH dosage was set as m(NaOH)/m(residue) = 0.00, 0.05, 0.10, 0.15, 0.20, 0.25, and 0.30. The results are detailed in Figure 4.

Figure 4.

Figure 4

Open in a new tab

Effect of NaOH dosage on the extraction efficiencies for vanadium and chromium.

Although KMnO4 had a strong oxidative ability, only 6.54% vanadium and 2.05% chromium were extracted in a neutral medium. As the NaOH dosage increased to m(NaOH)/m(residue) = 0.30, the extraction efficiency for vanadium was up to 97.24% and that for chromium was 56.20%, indicating that NaOH played an important role in the extraction process. The addition of NaOH not only acted as a reaction agent according to eqs 1–3 but also provided a strongly alkaline medium for dissolving high-valence vanadium (VO43–) and chromium (CrO42–). Meanwhile, impurities like Fe and Ca were retained in the filtrate residue due to their low solubility in a strongly alkaline medium.36 For avoiding corrosion of the experimental setup and for easy filtration, the NaOH dosage of m(NaOH)/m(residue) = 0.30 was selected as optimal conditions for further experiments.

Effect of Reaction Temperature

Based on the results in Figure 1, the process to extract vanadium and chromium was feasible thermodynamically, indicating that the reaction temperature played an important role in the extraction process. Thus, the effect of reaction temperature on the extraction process was investigated while the reaction time was kept at 90 min, the liquid-to-solid ratio was selected as 5:1 mL/g, the KMnO4 dosage was chosen as m(KMnO4)/m(residue) = 0.40, and the NaOH dosage was kept as m(NaOH)/m(residue) = 0.30. The reaction temperature was set as 30, 45, 60, 75, and 90 °C. The results are summarized in Figure 5.

Figure 5.

Figure 5

Open in a new tab

Effect of reaction temperature on the extraction efficiencies for vanadium and chromium.

The extraction efficiencies for vanadium and chromium were increased with the increasing reaction temperature according to Figure 5. About 68.13% vanadium and 36.41% chromium could be extracted even at a low reaction temperature of 30 °C, indicating that the influence of reaction temperature on the extraction process was not as significant as KMnO4 dosage and NaOH dosage. The activity of atoms, molecules, and reaction rate increased as the reaction temperature increased.8,25 The extraction efficiency could increase 29.11 percentages and 19.79 percentages for vanadium and chromium, respectively, when the reaction temperature increased to 90 °C. The increasing trend became smooth with the increase in reaction temperature; thus, 90 °C was selected as optimal conditions for further experiments.

Effect of Reaction Time

Figure 6 summarized the experimental results of the effect of reaction time on the extraction process under selected conditions: liquid-to-solid ratio of 5:1 mL/g, reaction temperature of 90 °C, m(KMnO4)/m(residue) = 0.40, m(NaOH)/m(residue) = 0.30, and reaction time from 30 to 90 min. Long reaction time could enhance the contact probability of reaction reagents. The low-valence vanadium and chromium in VCRR could be oxidized at enough reaction time. The extraction efficiency for vanadium was increased by nearly 45 percentages (from 52.83 to 97.24%) as the reaction time increased from 30 min to 90 min. Even though chromium was hard to extract, the extraction was increased from 26.06% at 30 min to 56.20% at 90 min. The extraction efficiency could not increase further with reaction time according to the increasing trend of extraction efficiency vs reaction time showed in Figure 6. Therefore, the reaction time of 90 min was selected as an optimal condition in the following experiments.

Figure 6.

Figure 6

Open in a new tab

Effect of reaction time on the extraction efficiencies for vanadium and chromium.

Effect of Liquid-to-Solid Ratio

The volume of the reaction medium would affect the solution viscosity and the solid–liquid mass transfer; therefore, the liquid-to-solid ratio showed a significant effect on the extraction process. A series of experiments were conducted to investigate the effect of the liquid–solid ratio on the extraction process. The liquid-to-solid ratio was set as 5:1, 6:1, 7:1, 8:1, and 9:1 mL/g, and other reaction conditions were kept constant: reaction temperature of 90 °C, reaction time of 90 min, m(KMnO4)/m(residue) = 0.40, and m(NaOH)/m(residue) = 0.30. The results are summarized in Figure 7. Interestingly, it was observed that the liquid-to-solid ratio showed no obvious effect on the extraction process, with the extraction efficiency nearly the same. The selected VCRR particles were below 75 μm, which was small enough to achieve an efficient contact of VCRR and KMnO4 in a concentrated NaOH solution. Meanwhile, the extraction process was mostly determined by the typical thermodynamic parameters like KMnO4 dosage, reaction temperature, and NaOH dosage and less by the kinetics parameters. Therefore, 5 mL/g was recommended for the optimum liquid-to-solid ratio in the extraction process for the sake of energy.

Figure 7.

Figure 7

Open in a new tab

Effect of liquid-to-solid ratio on the extraction efficiencies of vanadium and chromium.

Above all, 97.24% vanadium and 56.20% chromium could be extracted under the following optimal conditions: dosage of KMnO4 at m(KMnO4)/m(residue) = 0.40, dosage of NaOH at m(NaOH)/m(residue) = 0.30, reaction temperature of 90 °C, reaction time of 90 min, and liquid-to-solid ratio of 5:1 mL/g.

Kinetics Analysis

The extraction process was about the reaction between KMnO4, NaOH solution, and VCRR. It was a typical liquid–solid reaction process, so the extraction behavior might follow the shrinking core model.37,38 The simulated kinetics model could confirm the rate-controlling step during the extraction process. Three important models were discussed in all: (1) the diffusion of the reactant through the solution; (2) the diffusion of the reactant through a solid product layer; and (3) the rate of chemical reaction at the particle surface.10,21,39

The simulated model process was described as follows: the model assumed that the sphericity of the VCRR with an original radius as r0. During the extraction process, the interface was reduced toward the center of the sphere. Also, the distance was set as x at reaction time t. Then, the VCRR particle radius at time t was set as r.

graphic file with name ao1c04397_m011.jpg 11

The volume of the original VCRR particle and the real VCRR particle at time t during the extraction process could be calculated as eqs 12 and 13.

graphic file with name ao1c04397_m012.jpg 12
graphic file with name ao1c04397_m013.jpg 13

Then, the volume of fraction unreacted on a volume basis was

graphic file with name ao1c04397_m014.jpg 14
graphic file with name ao1c04397_m015.jpg 15
graphic file with name ao1c04397_m016.jpg 16
graphic file with name ao1c04397_m017.jpg 17
graphic file with name ao1c04397_m018.jpg 18
graphic file with name ao1c04397_m019.jpg 19
graphic file with name ao1c04397_m020.jpg 20

where D is the diffusion coefficient, Vm is the volume of the particle, and C0 is the concentration of the NaOH solution.

Substitute for x, dx, and r2.

graphic file with name ao1c04397_m021.jpg 21
graphic file with name ao1c04397_m022.jpg 22

Integrate.

graphic file with name ao1c04397_m023.jpg 23

At t = 0, η = 0 and c = −3.

graphic file with name ao1c04397_m024.jpg 24

The obtained eq 24 was applied to simulate the extraction model with the above experimental data, and the value of k could be obtained because it was the reaction rate constant corresponding to the slopes of the straight lines. The specific apparent activation energies for vanadium and chromium could be calculated with the Arrhenius equations according to the results shown in Figure 8. The result in Figure 9 displays that Ea for vanadium was calculated as 15.37 kJ/mol, indicating that the controlling step for vanadium extraction was the reactant through the solid product layer, while Ea for chromium extraction was calculated as 39.78 kJ/mol, indicating the extraction process was controlled by the surface chemical reaction. The calculated results displayed that vanadium was easier to extract than chromium. This finding was consistent with the above analysis. Compared with the previous works, the extraction of vanadium through the oxidation–extraction process with KMnO4 was suitable. However, for chromium extraction, KMnO4 might not be an appropriate selection.

graphic file with name ao1c04397_m025.jpg 25

where Ea is the apparent activation energy, A is the pre-exponential factor, and R is the molar gas constant.

Figure 8.

Figure 8

Open in a new tab

Plot of extraction kinetics of vanadium and chromium at various reaction temperatures.

Figure 9.

Figure 9

Open in a new tab

Natural logarithm of reaction rate constant vs reciprocal temperature of vanadium.

Conclusions

The VCRR containing large amounts of vanadium and chromium was an important resource for utilization. This paper investigated the oxidation–alkaline extraction of vanadium and chromium from VCRR with KMnO4. The following conclusions could be obtained:

  • (1)

    The E–pH diagram and thermodynamics analysis indicated that KMnO4 was suitable for the oxidation–extraction of vanadium and chromium from VCRR. The extraction efficiencies for vanadium and chromium were up to 97.24 and 56.20%, respectively, under optimal reaction conditions: reaction temperature of 90 °C, reaction time of 90 min, dosage of KMnO4 at m(KMnO4)/m(residue) = 0.40, dosage of NaOH at m(NaOH)/m(residue) = 0.30, and liquid-to-solid ratio of 5:1 mL/g. The retained Cr in the filtrate residue needed further treatment.

  • (2)

    Compared with low-valence vanadium, low-valence chromium was more difficult to extract. The oxidation–extraction behavior of vanadium and chromium from vanadium–chromium–reducing residue in a concentrated NaOH solution with KMnO4 were controlled by the reactant through the solid product layer and surface chemical reaction, respectively, and the apparent activation energies for the extraction of vanadium and chromium were 15.37 and 39.78 kJ/mol, respectively.

Materials and Methodology

Materials

The VCRR was obtained from Pan Gang Group Co., Ltd., Panzhihua, Sichuan Province, China. Figure 10 displays the main phases measured by X-ray diffraction (XRD) (XRD-6000, Shimadzu, Japan), which indicated that the vanadium existed in the low-valence state, like VOSO4 and Fe(V,Cr)2O4, and chromium mainly existed as Cr2(SO4)3 and Fe(V,Cr)2O4. The main element components in the residue were measured by X-ray fluorescence (XRF) (XRF-1800, Shimadzu, Japan), and the results in Table 1 display that vanadium accounted for about 3.11 wt % and chromium about 18.80 wt %.8−10,24,25

Figure 10.

Figure 10

Open in a new tab

XRD pattern of the vanadium–chromium reducing residue.

Table 1. XRF Analysis of the VCRR (wt %).

component O Cr Si Na S V
amount (wt %) 41.44 18.80 11.30 10.93 10.64 3.11
component Ca Cl Fe K    
amount (wt %) 1.94 1.06 0.37 0.17    
Open in a new tab

Experimental Procedure

The detailed extraction process of VCRR could be seen in our previous works8−10,22−25 or in the Supporting Information (Figure S1).

Acknowledgments

This work was supported by the Science and Technology Research Program of Chongqing Municipal Education Commission (Nos. KJQN201901403 and CXQT20026) and Chongqing Science and Technology Commission (No. cstc2018jcyjAX0018) and the National Natural Science Foundation of China (No. 51804062).

Supporting Information Available

The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acsomega.1c04397.

  • The detailed flow sheet of the experimental procedure (PDF)

The authors declare no competing financial interest.

Supplementary Material

ao1c04397_si_001.pdf (163.8KB, pdf)

References

  1. Wen J.; Jiang T.; Zheng X.; Wang J.; Cao J.; Zhou M. Efficient separation of chromium and vanadium by calcification roasting–sodium carbonate leaching from high chromium vanadium slag and V2O5 preparation. Sep. Purif. Technol. 2020, 230, 115881 10.1016/j.seppur.2019.115881. [DOI] [Google Scholar]
  2. Peng H. A literature review on leaching and recovery of vanadium. J. Environ. Chem. Eng. 2019, 7, 103313 10.1016/j.jece.2019.103313. [DOI] [Google Scholar]
  3. Li H.; Wang C.; Lin M.; Guo Y.; Xie B. Green one-step roasting method for efficient extraction of vanadium and chromium from vanadium-chromium slag. Powder Technol. 2020, 360, 503–508. 10.1016/j.powtec.2019.10.074. [DOI] [Google Scholar]
  4. Gilligan R.; Nikoloski A. N. The extraction of vanadium from titanomagnetites and other sources. Miner. Eng. 2020, 146, 106106 10.1016/j.mineng.2019.106106. [DOI] [Google Scholar]
  5. Zhao Q.; Liu C.; Shi P.; Sun L.; Jiang M.; Saxen H.; Zevenhoven R. Cleaner Production of Chromium Oxide from Low Fe(II)-Chromite. Minerals 2020, 10, 460. 10.3390/min10050460. [DOI] [Google Scholar]
  6. Nayak S.; S R.; P B.; Kale P. A review of chromite mining in Sukinda Valley of India: impact and potential remediation measures. Int. J. Phytorem. 2020, 22, 804–818. 10.1080/15226514.2020.1717432. [DOI] [PubMed] [Google Scholar]
  7. Langeslay R. R.; Kaphan D. M.; Marshall C. L.; Stair P. C.; Sattelberger A. P.; Delferro M. Catalytic Applications of Vanadium: A Mechanistic Perspective. Chem. Rev. 2019, 119, 2128–2191. 10.1021/acs.chemrev.8b00245. [DOI] [PubMed] [Google Scholar]
  8. Peng H.; Yang L.; Chen Y.; Guo J. A Novel Technology for Recovery and Separation of Vanadium and Chromium from Vanadium-Chromium Reducing Residue. Appl. Sci. 2019, 10, 198. 10.3390/app10010198. [DOI] [Google Scholar]
  9. Peng H.; Wang F.; Li G.; Guo J.; Li B. Highly Efficient Recovery of Vanadium and Chromium: Optimized by Response Surface Methodology. ACS Omega 2020, 4, 904–910. 10.1021/acsomega.8b02708. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Peng H.; Liu Z.; Tao C. Leaching Kinetics of Vanadium with Electro-oxidation and H2O2 in Alkaline Medium. Energy Fuel 2016, 30, 7802–7807. 10.1021/acs.energyfuels.6b01364. [DOI] [Google Scholar]
  11. Zhao Z.; He a.; Lin J.; Feng M.; Murugadoss V.; Ding T.; Liu H.; Shao Q.; Mai X.; Wang N.; Gu H.; Angaiah S.; Guo Z. Progress on the Photocatalytic Reduction Removal of Chromium Contamination. Chem. Rec. 2019, 19, 873–882. 10.1002/tcr.201800153. [DOI] [PubMed] [Google Scholar]
  12. Wang X.; Wang H.; Gao D.; Chen B.; Meng Y.; Wang M. A clean technology to separate and recover vanadium and chromium from chromate solutions. Hydrometallurgy 2018, 177, 94–99. 10.1016/j.hydromet.2018.03.003. [DOI] [Google Scholar]
  13. Wang X.; Gao D.; Chen B.; Meng Y.; Fu Z.; Wang M. A clean metallurgical process for separation and recovery of vanadium and chromium from V-Cr-bearing reducing slag. Hydrometallurgy 2018, 181, 1–6. 10.1016/j.hydromet.2018.08.008. [DOI] [Google Scholar]
  14. Wang M.; Chen B.; Huang S.; Wang X.; Liu B.; Ge Q.; Xie S. A novel technology for vanadium and chromium recovery from V-Cr-bearing reducing slag. Hydrometallurgy 2017, 171, 116–122. 10.1016/j.hydromet.2017.05.007. [DOI] [Google Scholar]
  15. Wen J.; Jiang T.; Zhou W.; Gao H.; Xue X. A cleaner and efficient process for extraction of vanadium from high chromium vanadium slag: Leaching in (NH4)2SO4-H2SO4 synergistic system and NH4+ recycle. Sep. Purif. Technol. 2019, 216, 126–135. 10.1016/j.seppur.2019.01.078. [DOI] [Google Scholar]
  16. Wen J.; Jiang T.; Xu Y.; Cao J.; Xue X. Efficient extraction and separation of vanadium and chromium in high chromium vanadium slag by sodium salt roasting-(NH4)2SO4 leaching. J. Ind. Eng. Chem. 2019, 71, 327–335. 10.1016/j.jiec.2018.11.043. [DOI] [Google Scholar]
  17. Wen J.; Jiang T.; Zhou M.; Gao H.-y.; Liu J.-y.; Xue X.-x. Roasting and leaching behaviors of vanadium and chromium in calcification roasting–acid leaching of high-chromium vanadium slag. Int. J. Miner., Metall. Mater. 2018, 25, 515–526. 10.1007/s12613-018-1598-3. [DOI] [Google Scholar]
  18. Matern K.; Weigand H.; Kretzschmar R.; Mansfeldt T. Leaching of hexavalent chromium from young chromite ore processing residue. J. Environ. Qual. 2020, 49, 712–722. 10.1002/jeq2.20071. [DOI] [PubMed] [Google Scholar]
  19. Equeenuddin S. M.; Pattnaik B. K. Hydrogeochemical evolution of hexavalent chromium at the Sukinda ultramafic complex in eastern part of India. Geochemistry 2020, 80, 125633 10.1016/j.chemer.2020.125633. [DOI] [Google Scholar]
  20. He Y.; Linqiang M.; Xiangxin X. Separation and recovery of chromium and vanadium from reduced vanadium-chromium precipitate by calcinations-alkaline leaching. J. Chem. Ind. Eng. 2014, 65, 948–953. [Google Scholar]
  21. Peng H.; Guo J.; Zheng X.; Liu Z.; Tao C. Leaching kinetics of vanadium from calcification roasting converter vanadium slag in acidic medium. J. Environ. Chem. Eng. 2018, 6, 5119–5124. 10.1016/j.jece.2018.08.003. [DOI] [Google Scholar]
  22. Peng H.; Liu Z.; Tao C. Selective leaching of vanadium from chromium residue intensified by electric field. J. Environ. Chem. Eng. 2015, 3, 1252–1257. 10.1016/j.jece.2015.03.031. [DOI] [Google Scholar]
  23. Peng H.; Yang L.; Chen Y.; Guo J.; Li B. Recovery and Separation of Vanadium and Chromium by Two-Step Alkaline Leaching Enhanced with an Electric Field and H2O2. ACS Omega 2020, 5, 5340–5345. 10.1021/acsomega.9b04346. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Peng H.; Liu Z.; Tao C. A green method to leach vanadium and chromium from residue using NaOH-H2O2. Sci. Rep. 2018, 8, 426 10.1038/s41598-017-18918-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Peng H.; Shang Q.; Chen R.; Leng Y.; Guo J.; Liu Z.; Tao C. Oxidative Leaching Kinetics of Vanadium from the Vanadium-Chromium-Reducing Residue with K2Cr2O7. ACS Omega 2020, 5, 8777–8783. 10.1021/acsomega.0c00339. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Xiong P.; Zhang Y.; Bao S.; Huang J. Precipitation of vanadium using ammonium salt in alkaline and acidic media and the effect of sodium and phosphorus. Hydrometallurgy 2018, 180, 113–120. 10.1016/j.hydromet.2018.07.014. [DOI] [Google Scholar]
  27. Chen B.; Huang S.; Liu B.; Ge Q.; Wang M.; Wang X. Separation and recovery of vanadium and chromium from acidic leach solution of V-Cr-bearing reducing slag. J. Environ. Chem. Eng. 2017, 5, 4702–4706. 10.1016/j.jece.2017.09.001. [DOI] [Google Scholar]
  28. Zhang J.; Zhang W.; Xue Z. An Environment-Friendly Process Featuring Calcified Roasting and Precipitation Purification to Prepare Vanadium Pentoxide from the Converter Vanadium Slag. Metals 2019, 9, 21. 10.3390/met9010021. [DOI] [Google Scholar]
  29. Zhu X.; Li W.; Tang S.; Zeng M.; Bai P.; Chen L. Selective recovery of vanadium and scandium by ion exchange with D201 and solvent extraction using P507 from hydrochloric acid leaching solution of red mud. Chemosphere 2017, 175, 365–372. 10.1016/j.chemosphere.2017.02.083. [DOI] [PubMed] [Google Scholar]
  30. Nguyen T. H.; Lee M. S. Separation of molybdenum and vanadium from acid solutions by ion exchange. Hydrometallurgy 2013, 136, 65–70. 10.1016/j.hydromet.2013.03.007. [DOI] [Google Scholar]
  31. Ye G.; Hu Y.; Tong X.; Lu L. Extraction of vanadium from direct acid leaching solution of clay vanadium ore using solvent extraction with N235. Hydrometallurgy 2018, 177, 27–33. 10.1016/j.hydromet.2018.02.004. [DOI] [Google Scholar]
  32. Yang X.; Zhang Y.; Bao S.; Shen C. Separation and recovery of vanadium from a sulfuric-acid leaching solution of stone coal by solvent extraction using trialkylamine. Sep. Purif. Technol. 2016, 164, 49–55. 10.1016/j.seppur.2016.03.021. [DOI] [Google Scholar]
  33. Tavakoli M. R.; Dreisinger D. B. Separation of vanadium from iron by solvent extraction using acidic and neutral organophosporus extractants. Hydrometallurgy 2014, 141, 17–23. 10.1016/j.hydromet.2013.10.008. [DOI] [Google Scholar]
  34. Banwen S.; Yuji L.. Inorganic Chemistry Series.; Science Press: Beijing, 1998. [Google Scholar]
  35. Peng H.; Guo J.; Liu Z.; Tao C. Direct advanced oxidation process for chromium(III) with sulfate free radicals. SN Appl. Sci. 2019, 1, 14 10.1007/s42452-018-0020-0. [DOI] [Google Scholar]
  36. Yang K.; Zhang X.; Tian X.; Yang Y.; Chen Y. Leaching of vanadium from chromium residue. Hydrometallurgy 2010, 103, 7–11. 10.1016/j.hydromet.2010.02.006. [DOI] [Google Scholar]
  37. Deng R.; Xie Z.; Liu Z.; Tao C. Leaching kinetics of vanadium catalyzed by electric field coupling with sodium persulfate. J. Electroanal. Chem. 2019, 854, 113542 10.1016/j.jelechem.2019.113542. [DOI] [Google Scholar]
  38. Wang X.; Jia Y.; Ma S.; Zheng S.; Sun Q. Effect of mechanical activation on the leaching kinetics of niobium-bearing mineralisation in KOH hydrothermal system. Hydrometallurgy 2018, 181, 123–129. 10.1016/j.hydromet.2018.08.012. [DOI] [Google Scholar]
  39. Luo M.; Liu C.; Xue J.; Li P.; Yu J. Leaching kinetics and mechanism of alunite from alunite tailings in highly concentrated KOH solution. Hydrometallurgy 2017, 174, 10–20. 10.1016/j.hydromet.2017.09.008. [DOI] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

ao1c04397_si_001.pdf (163.8KB, pdf)

Articles from ACS Omega are provided here courtesy of American Chemical Society

RESOURCES