Synthesis of chelating N-hydroxyl amine derivative and its application for vanadium separation from Abu Zeneima ferruginous siltstone ore, Southwestern Sinai, Egypt

ABTRACT To extract vanadium (V) ions from the ferruginous siltstone at Abu Zeneima in Southwestern Sinai, Egypt, a synthesized chelating N-phenyl acetyl-N-naphthyl hydroxyl amine (PANHA), was used. Complete characterization was carried out successfully to elucidate the structure using several techniques such as FT-IR,1H-NMR, 13C-NMR, GC-MS and TGA analysis performances. Improved experimental measurements, such as pH, shaking time, initial concentration of V(V), PANHA dosage, temp., and stripping agents, have been achieved with the solvent extraction technique. At 25 ℃ and 0.015 mole per liter through 30 minutes, PANHA/CHCl3 has an extreme retention potential of 50 mg per gram at 25 ℃ at pH 1.5 at 1:1 aqueous to organic phase ratio. The linear regression analysis, consisting of a log D track versus pH, shows a straight line with a slope of 0.859, indicates that a mole of H+ was released during the extraction. The stability constant (β), of PANHA-V(V) complex was calculated from the intersection (log β=1.7958), and it was found to equal 63.1. The stoichiometry mechanism among a chelating ligand of PANHA and V(V) indicates a roughly linear correlation with slope of 0.882 which explains that one mole of PANHA chelating ligand can react with one mole of V (V). According to the kinetic and thermodynamic interpretations, the pseudo-second order kinetic model predicted the kinetics of vanadium (V) extraction, the thermodynamic factors ΔS, ΔH, and ΔG were also measured. As the temperature rises, ∆G values rise from -10.45 kJ/mol at 198 K to -2.2 kJ/mol at 353 K. Vanadium may be stripped from the loaded PANHA/CHCl3, by 0.5M NaOH with a 99% efficiency rate. To obtain a vanadium concentrate (NH4VO3, AMV) with a vanadium content of 42.6 percent and pureness of 98 percent, the enhanced variables were finally put to use.


Introduction
In the metallurgical, chemical, and medicinal industries, vanadium is a rare metal and precious that is often used in alloys.It is also expected that the use of vanadium will increase as research, economy and the technology rise.Despite the fact that the world's vanadium resources are abundant, they will not be sufficient to meet demand in the next few decades, ensuring the sector's long-term viability [1][2][3].The most important vanadium resources are vanadium slag, stone coal, fly ash, oil ash, and wasted catalyst.Among the most important sources of vanadium are slag of vanadium (from steelmaking), coal of stone, oil ash, fly ash, and waste catalyst.According to the International Vanadium Slag Association, the secondary product of vanadium titanium magnet smelting accounted for extra than 38% of global vanadium fabrication in 2009 [4,5].
Recently, there has been a lot of interest in vanadium solvent extraction.Several organic extractants, including P538, P204, and HBL@101 extractants, were employed to extract vanadium from stone coal acid leach solution, which had to be neutralised to pH 2-3 [23,24].In the pH range of 5-7, the N263 extractant was also utilised for vanadium recovery, with an extraction efficiency of 90% [25].A binary extractant system composed of D2EHPA/PC88A and D2EHPA/TBP mixes was explored to separate vanadium through synergism from a multi-element sulphuric acid leaching solution to enhance extraction efficiency and selectivity [26][27][28].
Furthermore, different resins and adsorbents were utilised to extract vanadium from diverse matrices.The adsorption and elution of gallium(Ga), vanadium(V), and aluminium (Al) ions in alkaline solution on amidoxime resin was studied using batch and column studies [29].Comparisons between various cation exchangers (Amberlite IR-120, Dowex 50 W-X4-100, Dowex 50 W-X4) were also established to illustrate the adsorption behaviour of vanadium from high acidity leach liquors.Ion exchange resin granularity and ion exchange capacity vary [30].
The polyhydroxyl chelating resin D403 was employed in batch and column studies to extract tungsten (W) and vanadium (V) from molybdate solutions.The batch experiments indicated that tungsten and vanadium may be selectively absorbed by the D403 resin at a pH of around 9.25.Mo/V and Mo/W separation coefficients were determined to be larger than 45 and 18 [31].Furthermore, the complexing characteristics of Amberlite IRC-748, a chelating resin with an iminodiacetic acid group, for vanadium (V) adsorption were studied.The maximal absorption capacity at pH 2 was determined to be 94 mg/g [32].
Five resins (ZGA414, weak base), (D202, strong base), (D453, weak base), (D301FC, weak base) and (ZGA351, weak base) were evaluated for vanadium extraction from coal stone leach solution.At pH 2.5, ZGA414 resin exhibited exceptional vanadium(V) adsorption capability, with a maximum adsorption efficiency of 99.9% [33].Mo and V were separated from sulphate media using the anionic AG1-X8 resin.The greatest separation factor obtained by the resin at pH 1.2 was reported for Mo leaving V.As a result, AG1-X8 resin has the potential to be utilised to separate Mo and V [34].
For vanadium separation from an acidic media containing 2.06 g/L V in stone coal, D314 weak base resin was developed.With a contact time of 60 minutes at pH = 4, the maximal absorption capacity was determined to be 260 mg/g, resulting in a 99% recovery [35].In a macro-pore anion exchange resin synthesised via poly condensation of epichlorohydrin oligomer and 4-vinylpyridine, the static exchange capacity (SEC) for vanadium in 0.1 M HCI solution was determined to be 6.75 meq/g [36].
In the frequently used vanadium precipitation method, excess ammonium salt is utilised to convert the sodium salt of vanadium into ammonium vanadate, which may be pyrolysed into V 2 O 5 during calcination [37,38].Among vanadium compounds, NaV 2 O 5 is a popular kind of alkali vanadium oxide bronze.In the synthesis of NaV 2 O 5 , the hydrothermal technique is frequently utilised.The most frequent vanadium sources in the hydrothermal process are reported to be NaVO 3 and V 2 O 5 , whereas Na 2 CO 3 and Na 2 C 2 O 4 are typically employed as sodium source precipitating agents [39].
In this work, synthesised chelating N-phenyl acetyl-N-naphthyl hydroxyl amine (PANHA), was employed to extract vanadium from alkaline solution.The extraction and stripping parameters were optimised.The study investigated the kinetic, equilibrium, and thermodynamic aspects of vanadium extraction from Abu Zeneima ferruginous siltstone leach fluid.

Apparatus
The Sartorins TE 214S analytical balance with a maximum sensitivity of 10 −5 g was used to weigh all samples.The hydrogen ion concentration was measured with an error of ±0.1 using a Digimed DM-21 digital pH metre (Japan).For the equilibrium experiments, the contents of the flasks were shaken with a Vibromatic-384 shaker.The quantitative measurement of V(V) utilising the Pyrocatechol violet was performed using a single beam spectrometer, Meterch Inc. (SP-8001).(PCV, ɛ = 3.7 × 10 4 L.mol −1 .cm−1 ), indicator [44].The vanadium concentration obtained from the Abu Zeneima ferruginous siltstone leach liquor was identified using ICP-OES (Prodigy High Dispersion ICP, TExxLEDYNE-Leeman Labs USA).EDS and X-Ray Diffraction (XRD) methods, as well as a PHILIPS PW 3710/31 diffractometer, scintillation counter, Cu-target tube, and Ni filter at 40 kV and 30 mA, were also utilised.IR spectra were recorded by FT-IR 4100 Gasco-Japan spectrometer, using KBr disks. 1 H-NMR spectra were made by mercury 400 spectrometer and recorded at 400 MH Z .Spectroscopic analysis was performed at 293 K on diluted solution using DMSO solvent.Chemical shift (δ) is reported in ppm.Coupling constant (J) is reported in Hertz (Hz).GC-MS analyses were performed using Shimadzu Qp-2010 Plus spectrophotometer.All melting points were measured using a Reichert Thermovar apparatus.IR spectra and GC-MS analysis is performed at the Micro analytical centre at the Faculty of Science, Cairo University, Egypt and 1 H- 13 C-NMR analysis at The Main Chemical Warfare laboratories.The thermal stability was studied using thermo-gravimetric analyses (TGA), carried out in a nitrogen atmosphere using (Shimadzu TGA-50 Model) thermal analyser.

Chemical reagents
Thermo Fisher Scientific-Acros Organics Inc. donated the reactants phenyl acetic acid and N-naphthyl hydroxyl amine hydrochloride, which were used in this experiment.The sodium vanadate and SOCl 2 were supplied by Loba Chemie of India.POCH S.A., based in Poland, provided HCl, H 2 SO 4 , and HNO 3 , all of analytical purity.The KClO 3 and NaOH were provided by Scharlau Chemie S.A. in Spain.

Manufacturing of standard inventory solutions
To make a 1000 mg/L V(V) standard stock solution, dissolve 2.393 g of NaVO 3 in 1000 mL distilled water with 5 mL 10% NaOH.On the other hand, many standard stock solutions of 1000 mg/L of potential co-ions during V(V) extraction by PANHA/CHCl 3 have been produced by dissolving suitable weights of their salts in 1000 mL distilled water.

Manufacturing of leach liquid
Acidic agitation with H 2 SO 4 is applied to 1 kg of ferruginous siltstone from Abu Zeneima to remove some heavy metal, which is considered as impurities, namely: U, Cu, Cr, Pb, and Ni.The leaching parameters were tuned (leaching time: 2 h, H 2 SO 4 concentration: 100 g/L, particle size: −100 mesh, temperature: 80 °C, and solid-to-liquid-phase ratio: 1:3).Following filtering, nearly all vanadium (430 mg/kg) remained in the residue, whereas contaminants were transferred to the aqueous leach liquid.Following that, a second alkaline agitation leaching with NaOH was carried out to remove vanadium from the bearing residues.The leaching parameters were tuned (90 minutes duration time, NaOH concentration: 100 g/L, particle size: −100 mesh, temperature: 80 °C, and solid-to-liquidphase ratio: 1:3).The final leach liquor (3 L) was produced with 0.135 g/L vanadium (135 mg/L V, pH 12) and a leachability of 95.3%.HCl may be used to neutralise the produced alkaline solution to pH 8-9 in order to precipitate the existing Si 4+ as Si(OH) 4 and other impurities [45,46].
Using the Abu Zeneima ferruginous siltstone sample, researchers were able to determine the chemical composition and liquid waste of alkaline waste residual waste (major oxides and tracings).The information is contained in Tables 1, 2, and 3.

The extraction steps
To optimise V(V) extraction from synthetic solution by PANHA/CHCl 3 , the following variables were optimised: pH, shaking duration, starting V(V) concentration, PANHA dosage, temperature, and different co-ions.In these tests, 25 mL of synthetic V(V) solution containing 200 mg/L (3.92×10 −3 mol/L) was mechanically shaken with 25 mL PANHA/CHCl 3 for a predetermined amount of time.The distribution ratios for extraction, D, and stripping, D ʹ , were employed as the most essential indexes for assessing the efficiency of the solvent extraction process and were computed using the equation ( 1) [47,48]: Where C o and C a are the organic and aqueous-phase conc. of V(V), (mg/L), respectively.Meanwhile, the distribution coefficient (K d ) is determined using equation (2), where C i and C e are the initial and equilibrium vanadium ion concentrations, and V a and V o are the aqueous and organic phase volumes, respectively.The following equation ( 2) was used to determine the distribution coefficient: The extraction percentage (%E) was evaluated from the following equation ( 3): The stripping tests were carried out by shaking various volumes of the loaded organic phase and the aqueous solution of the stripping agent (0.5 mol/L NaOH) at room temperature for 15 minutes.After equilibration and settling, the two phases were completely separated.The concentration of the stripped V(V) ions was measured using known aliquot amounts carefully removed from the stripping aqueous phase.The percentage of stripping (% S) was determined using the following equation:

Preparation of N-phenyl acetyl-N-naphthyl hydroxyl amine (PANHA), chelating ligand
N-phenyl acetyl-N-naphthyl hydroxyl amine (PANHA) was synthesised in two steps.The first activation step begins by adding 0.01 mole from SOCl 2 (0.725 mL), to 0.1 mole of phenyl acetic acid (1.36 g), in an appropriate 25 mL of DMF as diluent.The mixture was refluxed at 90°C for 7 h.The progress of the reaction was monitored by paper chromatography (PC) using PC sheets using acetone.Spots on the TLC plates were visualised with a UV lamp.The resulted phenyl acetyl chloride appears as colourless liquid with a strong odour and is denser than water and DMF (0.95 g/mL), having a density of ≈1.1 g/mL.The N-naphthyl hydroxyl amine hydrochloride (0.01 mole, 1.9 g), was neutralised firstly by NaOH (0.01 mole, 0.4 g), for one hour at ambient temperature before the coupling step.The second coupling step begins by adding the resulted phenyl acetyl chloride to the neutralised N-naphthyl hydroxyl amine.The mixture was allowed to condense for 36 h at 120°C.At the end of the reaction, the product was obtained via evaporating the solvent.The resulting residue was washed and the recrystallisation process was carried out using mixture of ethanol/DMF.The Synthesis of N-phenyl acetyl-N-naphthyl hydroxyl amine (PANHA), chelating ligand is illustrated in scheme 1.

Characterisation of N-phenyl acetyl-N-naphthyl hydroxyl amine (PANHA), chelating ligand
The product yield was found to be 2. Fourier transformation infrared spectroscopy (FT-IR) is used to anticipate numerous function groups in the synthesised chelating ligand.The FT-IR spectra of the PANHA and its complex with V(V) are shown in Figure 1.It was found that the PANHA has a strong band, centred at nearly 3275.57cm −1 , which attributed to the stretching vibration of the -OH group.The stretching vibration of OH group was found to be vanished after chelation with V(V) ions, means that -OH group participates in the chelation.The vibrational bands which revealed at 3050.36, 2900, 1690 and 1475 cm −1 may be due to the vibrations of the -CH aromatic, -CH aliphatic, -C = O and N-O bands, respectively.FT-IR helps us to predict the viability or vanishing of some function groups.The appearance of new band in the chelate at 485 cm −1 may be due to the formation of V-O bond [49].H-NMR analysis with energy of 400 MH Z and DMSO as a diluent is an effective and helpful tool which gives significant data about protons in the synthesised ligand which assist in the structure prediction.The main δ (ppm) appears around 7.24 and 7.52 are related to aryl and naphthyl protons, respectively.Also, it was found that protons of OH and methylene groups appear at δ (ppm) around 7.18 and 3.61, respectively.Characterisation of PANHA chelating ligand using 1 H-NMR is illustrated in supplemental file S1. which gives significant data about number of carbon atoms in the synthesised ligand.The main δ (ppm) appeared around 128.5-134 ppm, which is related to aryl carbon.The naphtyl carbon assignments were found to appear around 120-136.5.Also, it was found that carbons of carbonyl and methylene groups appeared at δ (ppm) around 172 and 40.3 ppm, respectively.Specification of PANHA chelating ligand using 13 C-NMR is illustrated in supplemental file S2.
Gas chromatography with Mass spectrometer unit (GC-MS), also considered as an influential and powerful tool for the prediction of the molecular formula, CHNO elemental analysis, purity and the more stable fragment [m/z] + .The molecular ion peak which has a value of 277 ppm represents the molecular weight of the synthesised ligand.Some important fragmentation patterns were established such as the fragments at m/z of 91 and 128 which represents tropolium cation and naphthalene ring.The whole analysis performed assures a satisfactory synthesis of PANHA ligand.Specification of PANHA chelating ligand using GC-MS is illustrated in supplemental file S3.
The thermal stability of PANHA and PANHA-V was characterised by TGA analysis in nitrogen atmosphere.As shown in the supplemental file S4, it was found that PANHA ligand exhibited somewhat a good thermal stability at which the degradation starting with ≈ 7% weight loss from its total weight at ≈ 150°C.The PANHA decomposition reached the maximum at ≈ 300°C with a weight loss of ≈ 95% leaving behind ≈ 5% tar deposits.It was found that the presence of vanadium with PANHA imparts somewhat more thermal stability to PANHA-V chelate.The complex was found to be thermally stable till ≈ 180°C.The thermal decomposition of PANHA-V was started at ≈ 200°C with a weight loss of ≈ 15% and reached maximum at ≈ 400-500°C .The remaining ≈ 10% deposit thinks it is V 2 O 5 .
Finally, according to the previous analysis, the structure of the complex and the chelation mechanism may be postulated as in Scheme 2. Scheme 2. A postulated chelation mechanism of VO 2+ with PANHA ligand.

The influence of pH
As pH affects the aqueous chemistry of vanadium and the characteristics of PANHA active sites, pH is critical for maintaining V(V) at all active extractant sites [50].Figure 2 illustrates the HYDRA-MEDUSA programme's speciation of vanadium ions at various pH values.According to reports, there are several V(V) species in solution.These are divided into cationic, neutral, and anionic species.Vanadium is primarily found in the cationic species VO 2 + till pH 2. Anionic and polynuclear species such as H 2 V 10 O 28 4-, H 3 V 10 O 28 3-, HV 2 O 7 3-, and VO 3 OH 2-are detected above pH 3 up to pH 12 [51,52].The retention of V(V) on PANHA was investigated at room temperature for 5 minutes using 25 mL of 200 mg/L V(V), (3.92×10 −3 mol/L) solution and 25 mL of 0.015 mol/L PANHA/CHCl 3 at pH ranged between 0 and 5. Figure 3 depicts the acquired data, which reveal that there is a maximum retention of V(V) at pH 0-1.5 (99.5%), since VO 2 + ions predominate in this range.From pH 2 to 3.5, the vanadium anionic complex species begins to appear at which the retention efficiency decreases.Vanadium retention begins to vanish from pH 2-3.5 and reaches a minimum at pH 3.5.As a result, a proposed pH 1.5 is the optimal pH for V(V) retention on PANHA/CHCl 3 , with a retention capacity of q e = 37.5 mg/g (75%).Linear regression analysis (slope analysis), comprising a plot of log D against pH gives a straight line with a slope of 0.859 and R 2 = 0.93 (Figure 4).The slope value specifies the number of hydrogen ions released during the formation of the PANHA-V(V) complex, so it indicates that one mole of hydrogen ion was released in the aqueous medium during the extraction procedure.The stability constant (β), of the PANHA-V(V) complex was calculated from the interception (log β = 1.7958), and it was found to be equal to 63.1.

The influence of equilibration time
One of the most important aspects in economics is the time of balance.The impact of V(V) hold-up at equilibrium time is investigated by utilising a 3.92 × 10 −3 mol/L solution of 0.015 mol/L PANHA/CHCl 3 and the aqueous 25 mL V(V) solution at pH 1.5.The retention of V(V) is increased after 30 minutes, as shown in Figure 5 and reaches a maximum value (42.5 mg/g, 85%) and is nearly constant over the next 120 minutes.Consequently, 30 minutes in the following tests were deemed sufficient to achieve balance and were used in all future experiments.
The rate of vanadium ion extraction by PANHA/CHCl 3 is described by the kinetic studies.The kinetic parameters help to estimate adsorption rates and give essential information for extraction process design and modelling.The mechanism of V(V)  extraction PANHA/CHCl 3 and the rate constants of the extraction process were calculated using pseudo-first-and second-order kinetic models [53,54].The pseudo-first order kinetic model is described by the following equation: Where K 1 (min .-1 ) represents the rate constant, q e represents the amount of vanadium extracted per unit mass at equilibrium, and q t represents the amount extracted per unit time (t, min.−1 ).Plotting Log (q e -q t ) versus t produces a straight line, as shown in Figure 6, which reveals the first-order extraction rate constant K 1 and q e values from its slope and intercept.According to the plot diagram, the pseudo-first order kinetic model does not utilise to fit the practical data in Table 4.The calculated value of q e was found to be 6.593 mg/g with extraction rate (K 1 = 0.0624 min.−1 , R 2 = 0.9682), which is very far from the determined practical retention capacity of 42.5 mg/g.On the other hand, the pseudo-second order kinetic model is represented by the following equation [55]: The rate constant (g/mg.min.) is denoted by K 2 .The slope of the straight line charting t/q t vs t is 1/q e , and the intercept is 1/k 2 q e 2 .It was found that pseudo-second-order kinetic model may be utilised to explain the practical data in Table 4, as illustrated in Figure 7.The estimated q e was 44.24 mg/g, with a correlation coefficient R 2 = 0.999 and an extraction rate of (K 2 = 0.0176 g/mg.min.).According to the findings, the second order kinetic model is more consistent with the experimental data and hence more suited to the extraction system under consideration.

The influence of initial V(V) concentration
The influence of the initial vanadium concentration on V(V) extraction efficiency is an essential element to study since it allows us to determine prospective retention power.Figure 8 illustrates the first and second stages of a plot of initial V(V) conc.against V(V) extraction efficiency.Because the number of chelating active sites in PANHA ligand is more than the number of vanadyl ions, there was a substantial consistency in V(V) efficiency from 0.49 to 2.45 × 10 −3 mol/L V(V) in the first step.The extraction efficiency decreases in the second stage when vanadyl ions increase from 2.94 to 9.8 × 10 −3 mol/L V(V), owing to the saturation of PANHA active sites with vanadyl ions (conc. of vanadyl ions is higher than PANHA active sites).At room temperature, a maximum value of V(V) extraction efficiency (99.5%) is recorded at a V(V) conc. of 2.744 × 10 −3 mol/L.

The influence PANHA dose
The PANHA dose is critical for effective vanadyl ion retention since it determines the system's equilibrium.The impact of PANHA doses ranging from 0.001 to 0.03 mol/L on the efficiency of V(V) extraction was studied.Figure 9 shows that increasing the PANHA dose from 0.001 g to 0.012 mol/L increases V(V) extraction efficiency, then consistency occurs from 0.015 g to 0.03 mol/L as the number of PANHA active sites exceeds the number of vanadyl ions.With a 99.5% extraction efficiency, the total extraction potential of 0.015 mol/L PANHA is 42.5 mg/g.Hence, 0.015 mol/L PANHA is considered as optimised conc.chosen for subsequent extraction experiments In order to prove that the retrieved complex species is composed of complex species, researchers investigated the plot of log D versus PANHA concentration at equilibrium.Data obtained by the linear regression plot in Figure 10 indicate that a coefficient of correlation (R 2 = 0.9771) at a path of 0.882 is explained by the stoichiometry mechanism  among a chelating ligand of PANHA and V(V) that indicates a roughly linear correlation, therefore explains the stoichiometry between the PANHA chelating ligand and V (V) as one mole of PANHA nearly reacts with one mole of V(V).

The influence of aqueous to organic (A/O) phase ratio
Shaking various ratios of aqueous phases with the appropriate organic solvent yielded the equilibrium curve.The impact of aqueous to organic (A/O) phase ratio on V(V) extraction was investigated using varied (A/O) phase ratios ranging from 4/1 to 1/4 at room temperature, shaking period of 30 minutes, pH = 1.5, and 0.015 mol/L PANHA/CHCl 3 .According to Figure 11, the extraction efficiency progressively improves from the ratio of 4/1 to 1/1, then remains constant until the ratio of 1/4.As a result, the 1/1 (A/O) phase ratio was chosen as the optimum phase ratio, with an extraction efficiency of 99.5%.

The thermodynamic characteristics
The impact of temperature on V(V) extraction efficiency is studied by contacting 25 mL of 0.015 mol/L PANHA/CHCl 3 with 25 mL of 3.92 × 10 −3 mol/L aqueous vanadium solution at pH 1.5 for 30 minutes at temperatures ranging from 25 to 80 °C.It was observed that when temperature increases from 25°C to 80°C, V(V) efficiency decreases from 50 mg/g to 33.75 mg/g.The impact of temperature on V(V) uptake is seen in Figure 12.This pattern implies that V(V) extraction onto PANHA is an exothermic process.
For thermodynamic calculation of parameters Gibbs-free energy (∆G, kJ/mol), enthalpy change (∆H, kJ/mol), and entropy change (∆S, J/mol.K).The following formulas were used to measure the thermodynamic parameters [48,56,57]: Where R is the universal gas constant (8.314J.mol −1 .K −1 ) and T is the in Kelvin (K). Figure 13 demonstrates that the values of ∆H and ∆S may be calculated from the slope and interception of the Log K d against 1/T plot, which yields a slope of 2880.7 and an interception of −7.861 with a correlation coefficient, R 2 = 0.9613.
As shown in Table 5, vanadyl ion retention onto PANHA is an exothermic mechanism ∆H, which means that some heat is generated during the extraction process.Through the course of the extraction, the minor negative value of ∆S shows a slight reduction in unpredictability (randomness).It was demonstrated that the extraction mechanism is thermodynamically spontaneous and possible at low temperatures by the presence of negative ∆G values.The fact that the ∆G values rise in response to increasing temperature, from −10.45 kJ/mol at 198 K to −2.2 kJ/mol at 353 K, shows that extraction is preferable at lower temperatures than at higher ones.The Arrhenius equation is significant because the Where K d is the partition coefficient, E a denotes the extraction activation energy (KJ/mol), R denotes the molar gas constant (8.314J/mol.K), T denotes the temperature in Kelvin, and A denotes the Arrhenius constant.The activation energy required for vanadyl ion extraction was calculated to be −10.39kJ/mol, and the Arrhenius constant to be 1.38 × 10 −8 .This means that the extraction of vanadyl ions by PANHA is an exothermic process that occurs spontaneously at room temperature without the requirement for activation energy.

The influence of co-ions
The investigated ions were detected in the ferruginous siltstone leach fluid as co-ions with V (V).When the pH is increased to 9, most of the interfering ions precipitate and vanadium is left behind.Virtually vanadium-pure leach liquor with a trace of interfering ions was created using this basic principle.

Vanadium(V) elution
The removal of V(V) from PANHA was investigated using 10 mL of stripping volume per 25 mL of loaded PANHA at room temperature.The data in Table 6 show that increasing the concentration of the stripping agent boosts the back extraction of V(V).The efficiency at stripping was attained by 10 mL of 1 M HNO 3 , 2 M H 2 SO 4 , 2 M HCl, and (0.5 M) NaOH of 25 mL PANHA primed.

Application: V(V) recovery from Abu Zeneima ferruginous siltstone ore sample by PANHA
According to the data provided above, PANHA can be used to extract, purify, and concentrate V(V) from acidic solution (pH 1.5).As a consequence, it was tested on previously produced Abu Zeneima ferruginous siltstone leach liquor, which yielded 136 mg/L V(V).Under previously calculated optimal conditions, 3 L of leach liquid was mixed with 3 L of PANHA/CHCl 3 (pH: 1.5, equil.time: 30 minutes, temperature: 25°C, A:O,1:1).According to the results, the V(V) extraction efficiency has reached 99%.However, it has been observed that 1.2 L of 0.5 M NaOH may easily strip the loaded V(V) from PANHA.The vanadium concentrate is tested using XRD, EDS, and ICP-OES to determine the V(V) concentration and associated metal ions.The XRD figure clearly indicates a distinctive assignment for ammonium meta vanadate concentration that occurs at 2θ (15.2°, 18.3°, 21.4°, 28.33° and 30.78°).Furthermore, the vanadium peaks in ammonium meta vanadate may be observed as two separate peaks on the EDS diagram at 5 and 5.48 Kev.The   Figure 16 illustrates a suggested schematic flow design for claimed vanadium recovery using PANHA from an Abu Zeneima ferruginous siltstone ore sample.

Conclusion
A successful synthesis of chelating N-phenyl acetyl-N-naphthyl hydroxyl amine (PANHA) was used to extract and recover vanadium (V) ions from the Abu Zeneima ferruginous siltstone in Southwestern Sinai, Egypt.Complete characterisation was carried out successfully using several techniques such as FT-IR, 1 H-NMR, 13 C-NMR, GC-MS and TGA analysis techniques.The extraction method was optimised by shaking a 25 mL solution volume containing 3.92 × 10 −3 mol/L V(V) with 0.015 mol/L PANHA at pH 1.5 for 30 minutes at room temperature with a 1:1 aqueous-to-organic-phase ratio.At 25°C, the extractant has a maximum retention potential of 50 mg/g under these circumstances.The kinetic modelling data gathered matched well with the pseudo-second order rather than the first order, which describes the extraction process better.In terms of thermodynamic modelling, the investigated thermodynamic parameters resulted in a tiny negative value of ΔS, indicating a modest decrease in randomness during extraction.The presence of negative ΔG values implies that the extraction process is thermodynamically spontaneous and feasible at low temperatures.Furthermore, the rise in ΔG values with increasing temperature, from −10.45 kJ/mol at 198 K to −2.2 kJ/mol at 353 K, suggests that extraction is preferable at low temperatures.Vanadium may be easily extracted from primed PANHA using 0.5 M NaOH stripping agent, which has a maximum elution efficiency of 99% as sodium vanadate.Finally, vanadium concentrate (AMV) is precipitated from the stripped solution by mixing 0.25 g KClO 3 as an oxidant with NH 4 OH at pH 8.5 for 2 hours and stirring constantly, where vanadium is precipitated as ammonium meta-vanadate, AMV (NH 4 VO 3 ) with vanadium concentrate of 42.6% and a purity of 98% with low amount of metal ion contaminants.

Figure 2 .
Figure 2. The HYDRA-MEDUSA software a speciation diagram for vanadium ions at various pH.

Figure 15 .
Figure 15.EDS of the furnished NH 4 VO 3 from Abu Zeneima ore sample.

Figure 16 .
Figure 16.A flow diagram declares the setting up of NH 4 VO 3 from Abu Zeneima ferruginous siltstone ore sample furnished by PANHA ligand.

Table 2 .
Trace elements in a sample of Abu Zeneima ferruginous siltstone.

Table 3 .
The chemical composition of alkaline spent residue leach liquor (3 L).

Table 4 .
The kinetic parameters of V(V) extraction by PANHA ligand.

Table 5 .
The thermodynamic indices of V(V) extraction by PANHA.
[58,59]O 3 as an oxidant (for one litre of solution), with NH 4 OH at pH 8.5 with constant stirring for 2 hours, where vanadium precipitates as ammonium meta vanadate, AMV, (NH 4 VO 3 )[58,59], which washed by 5% NH 4 OH and dried in an electrical furnace at 110°C for 3 hours.

Table 6 .
The influence of stripping agents on V(V) stripping efficiency from loaded PANHA.

Table 7 .
ICP-OES specifics of Abu Zeneima vanadium concentrate furnished by PANHA ligand.aredepicted in Figures14, 15, and Table7.The vanadium concentration in the vanadium concentrate produced by PANHA is 42.6%, with a purity of 98% and a low level of metal ion contaminants, according to the results. findings