Extraction Of Ga Research Articles

Mechanistic deduction of gallium(III) extraction using halogenated secondary amides: Spectroscopic interpretation

Secondary amides act as bifunctional compounds to extract metal anionic species due to the presence of N–H hydrogen and protonated carbonyl oxygen atoms. To exclude the latter function with stronger interaction and less extraction selectivity for metal anionic species, two secondary amide compounds with halogen atoms, namely N-(2-ethylhexyl)-2,2,2-trichloroacetamide as TCAA and N-(2-ethylhexyl)-2,2,2-tribromoacetamide as TBAA, have been synthesised to investigate the efficiency and mechanism of Ga(III) extraction for comparison with N-(2-ethylhexyl)-2,2,2-trifluoroacetamide (TFAA). The 1H NMR spectroscopy results indicated the absence of proton extraction from the carboxylic oxygen atoms of both halogen-containing amides at sufficiently high concentrations of HCl. The three amides exhibited preferential extraction of Ga(III) compared to other metals in highly acidic media. A slope analysis was conducted to assess the stoichiometry for the extraction of Ga(III). The FT-IR and 1H NMR spectroscopies were employed to elucidate the extraction mechanism of GaCl4– using TCAA and TBAA. Therefore, the hydrogen atoms of the N–H group of both amides, with extremely weak δ+ nature, exhibited a distinct extractive preference for anionic GaCl4–. Following the forward extraction, Ga(III) was effectively separated from the organic phase through stripping with distilled water. The extraction efficiencies of GaCl4– among the three amides are not followed by the strength of electron-withdrawing nature of halogen atoms, but the strength of intra- or intermolecular interactions of the amides. This argument was substantiated by calculations using density functional theory (DFT).

Nucleon isovector axial form factors

We present results for the isovector axial vector form factors obtained using thirteen 2+1+1-flavor highly improved staggered quark (HISQ) ensembles generated by the MILC collaboration. The calculation of nucleon two- and three-point correlation functions has been done using Wilson-clover fermions. In the analysis of these data, we quantify the sensitivity of the results to strategies used for removing excited state contamination and invoke the partially conserved axial current relation between the form factors to choose between them. Our data driven analysis includes removing contributions from multihadron Nπ states that make significant contributions. Our final results are gA=1.292(53)stat(24)sys for the axial charge; gS=1.085(50)stat(103)sys and gT=0.991(21)stat(10)sys for the scalar and tensor charges; ⟨rA2⟩=0.439(56)stat(34)sys fm2 for the mean squared axial charge radius, gP*=9.03(47)stat(42)sys for the induced pseudoscalar charge; and gπNN=14.14(81)stat(85)sys for the pion-nucleon coupling. We also provide a parametrization of the axial form factor GA(Q2) over the range 0≤Q2≤1 GeV2 for use in phenomenology and a comparison with other lattice determinations. We find that the various lattice data agree within 10% but are significantly different from the extraction of GA(Q2) from the ν-deuterium scattering data. Published by the American Physical Society 2024

Utilization of an amidoxime resin waste to prepare solvent-impregnated resins (CA−12/SIRs) for the extraction of Ga(III) from acid solutions

Solvent-impregnated resins (CA−12/SIRs) have been prepared by using amidoxime resin waste as a polymeric support. The process of gallium (Ga) adsorption onto CA− 12/SIRs from a hydrochloric acid solution was examined in a batch experiment. It was found that CA− 12/SIRs exhibits excellent adsorbent properties with a saturated adsorption capacity of up to 31.2 mg·g−1 (318 K). In addition, CA− 12/SIRs showed an outstanding separation ability for Ga(Ⅲ), with a partition coefficient as high as above 2500 mL·g−1. The optimum pH value was found to be 2.75. Moreover, CA− 12/SIRs maintained an excellent adsorption performance for Ga(III), even after ten adsorption-elution cycles. For practical applications, the adsorption percentage of Ga(III) onto CA− 12/SIRs reached more than 99 % when using hydrochloric acid and sulfuric acid solutions. Thus, a low-cost adsorbent has been developed in the present study by which it is possible to purify gallium. Moreover, this study has provided a new direction for also other types of waste resins in the preparation of impregnated resins.

Preparation of graphene-based surface ion-imprinted adsorbent for Ga(Ⅲ) selective extraction from acid leaching of fly ash

To meet the requirements of Ga(Ⅲ) selective adsorption from acid leaching of fly ash, a grapheme-based Ga(Ⅲ) imprinted polymer is developed by combining adsorption method with surface ion imprinting technology. The obtained Ga(Ⅲ) imprinted polymer can effectively adsorb Ga(Ⅲ) with a maximum adsorption capacity of 221.56 mg g−1 at an initial concentration of 200 mg/L within 240 min. The pseudo-second order model (R2 = 0.9882) and Langmuir isotherm (R2 = 0.9628) fitted the Ga(Ⅲ) adsorption data well. In addition, the imprinted adsorbent exhibits significant selectivity towards Ga(Ⅲ) in a simulated acid leaching of fly ash. The selectivity coefficients of Ga(Ⅲ) with respect to Al(Ⅲ), Fe(Ⅲ), Mg(Ⅱ), and Ca(Ⅱ) are 10.09, 3.36, 18.50, and 55.50, respectively. The synthesized imprinted adsorbent exhibits excellent regeneration ability, maintaining 85.71% of its initial adsorption capacity after 5 adsorption-regeneration cycles. The binding energy of Ga(Ⅲ) to functional monomers is calculated as −16.79 kJ mol−1, which confirms that Ga(Ⅲ) can be effectively adsorbed. The theoretical simulated calculation results are basically in consistence with the experimental results, which confirms the selective adsorption mechanism of Ga(Ⅲ). Therefore, it provides a new idea for the extraction of Ga(Ⅲ) from acidic environments.

STUDY OF CONDITIONS FOR THE ASSOCIATED EXTRACTION OF VANADIUM AND GALLIUM DURING ALKALINE LEACHING OF RAW ALUNITE ORE

Alunite ore containing a significant amount of aluminum, iron oxide, titanium dioxide, and other valuable components (Ga – 0.003 wt%, V – 0.0315 wt.%) is the main raw material for the production of alumina and promising raw material for the production of gallium and vanadium. This paper studies the dynamics of the distribution of gallium and vanadium in the liquid phase during the dissolution of raw alunite in an alkaline solution are studied. The results have showed that alkali concentration, leaching temperature, liquid-to-solid ratio have a significant effect on the degree of extraction of these elements from solution. It has been found that when raw alunite ore is leached with a 5% NaOH solution (S:L=1:6) for 2 hours, the degree of extraction of Ga and V is, respectively, 50.2 and 59.23% of their total content in the rock

Synergistic Extraction of Ga(III) from Chloride Solution by Mixture of Cyanex 272 and Alamine 336

Aming to select a suitable system for the synergistic solvent extraction of Ga(III), solvent extraction (SX) experiments were carried out by using acidic organo-phosphorous extractants, namely P204, P507 and Cyanex 272, and their mixtures with neutral extractants (TBP, N503) or amine extractants (Alamine 336). Among the studied mixtures, a remarkable synergistic effect for Ga(III) extraction was resulted by the combination of Cyanex 272 and Alamine 336 and the maximal synergistic enhancement coefficient reached 3.11. Compared to the single Cyanex 272, higher equilibrium pH values were observed when mixture of Cyanex 272 and Alamine 336 was employed. The extraction of hydrogen ions by Alamine 336 during the reaction was considered to be responsible for the synergistic extraction, and thus the the extraction of Ga(III) by Cyanex 272 was promoted. Finally, the synergistic extraction stoichiometry of mixture of Cyanex 272 and Alamine 336 for Ga(III) was projected by slope analysis. Ga(OH)A2 was resulted to be the composition of extracted complexes.

Extraction and separation of gallium by solvent extraction with 5-nonyl-2-hydroxyacetophenone oxime: Fundamentals and a case study

The rapid growth of the electronics and energy industries has necessitated an increased focus on strategic elements in recent years. Gallium is one of the most sought-after elements due to its widespread use in electronic components as well as nuclear and other energy-related applications. Gallium was extracted and separated using 5-nonyl-2-hydroxyacetophenone oxime (NHAO), which was employed for the first time in this study. Traditional log DM-log [Extractant] analysis shows that the extractant has separated Ga as a complex of 2:1 (extractant: metal) ratio. Using 0.5 M NHAO in benzene with aqueous / organic ratio of 1/1, extraction of Ga (99.2%) was completed in about 7 min at room temperature. Based on the McCabe–Thiele diagrams constructed, 2 stages are sufficient for the extraction and stripping of Ga. The selectivity or separation factor (Ga /M) > 63 was obtained for all interfering metal ions examined. Additionally, 0.5 M H2SO4 selectively stripped almost 98.8% of the Ga from the loaded NHAO. The thermodynamic analysis demonstrated that Ga extraction by NHAO is an exothermic process. Finally, the best extraction parameters for separating gallium from reference (NIM-L) and black mica (BM) source materials bearing gallium were applied with good accuracy.

Extraction of Au(III) Using Aromatic Ketones in Acidic Chloride Media

Recently, the extraction of Au(III) using the series of aliphatic ketones in hydrochloric acid media has been investigated in detail. The present study describes the extraction behaviors of Au(III) using a series of aromatic ketones, which has never been reported. Aromatic ketones with shorter alkyl side chains showed higher extractability. The rapid extraction and the extraction capacity using aromatic ketones were comparable to the industrial extractant dibutyl carbitol (DBC). Aromatic ketones, except acetophenone, are less soluble in water than DBC. The flash points of aromatic ketones are satisfactorily high for industrial operation, but their specific gravities comparable to that of water are unwelcome. Butyrophenone selectively extracted Au(III) from many other metals, except for high extraction of Fe(III) and Ga(III) at high concentrations. Au(III) extracted using butyrophenone recovered quantitatively as metallic gold by reduction using oxalic acid.

Synthesis of UiO-66 series metal–organic framework composites and the adsorption effect on gallium

It is an urgent problem to alleviate the contradiction between the supply and demand of gallium (Ga) resources and improve the extraction and utilization efficiency of Ga resources. The GO/UiO-66-NH2 composite adsorbent was synthesized by hydrothermal synthesis of graphene oxide (GO) and UiO-66-NH2 series metal–organic skeleton, which was employed for efficient recovery and extraction of Ga in solution. The morphology, structure, elemental composition, and chemical properties of the composite adsorbent were studied by a series of batch experiments, respectively. The effects of the amount of adsorbent, adsorption time, initial concentration, and pH value of the solution on the adsorption effect were investigated. Results found that the adsorption mechanism of Ga by 4-GO/UiO-66-NH2 is mainly ion exchange forming chelate, accompanied by electrostatic interaction. The optimized adsorption conditions for reaching the saturated adsorption capacity of 661.67 mg/g Ga were found to be pH 9 and the temperature 313 K. The results of thermodynamic study pointed out the adsorption of Ga is spontaneous and feasible. The aforementioned results demonstrate that GO/UiO-66-NH2 composite adsorbent has strong adsorption performance and application potential for the recovery and exploitation of Ga, offering practical and theoretical support for the future development and utilization of Ga resources.

The Effect of Physical Separation and Calcination on Enrichment and Recovery of Critical Elements from Coal Gangue

Critical metallic elements in coal gangue have great utilization potential, especially due to the current shortage of these metals. This paper focused on examining the feasibility of physical separation (screening and float-sink tests) and calcination treatment for the enrichment of critical elements (Li, Ga, and rare earth elements plus yttrium (REY)) from coal gangue. The impacts of these enrichment methods on the acid leaching recovery of these elements were then studied. Screening tests indicated that Li and Ga were enriched in >0.125 mm size fraction and the content of REY was highest in <75 μm size fraction. Float-sink tests showed that high-density fractions were enriched in Li and Ga, and low-density fractions were enriched in REY. Physical separation cannot significantly improve the leaching rate of Li, Ga, and REY. Notably, Li, Ga, and REY were enriched significantly, and their acid leaching recoveries were increased by 54~68% after calcination under 400 °C. Sequential chemical extraction tests showed that the majority of insoluble Li, Ga, and REY was converted into soluble forms at the above temperature, which is attributed to the formation of amorphous metakaolinite and the decomposition of organic matter. Based on the results, a conceptually combined flowsheet was proposed for the extraction of Li and Ga from coal gangue.

Quantitative determination of plant hormones and derivatives in biogas slurry using on-line solid phase extraction with high performance liquid chromatography (On-Line SPE HPLC)

A novel method using on-line solid phase extraction coupled with high performance liquid chromatography (On-line SPE HPLC) was developed to measure three important plant hormones and two indole derivatives in the biogas slurry. These measured substances include abscisic acid (ABA), gibberellins (GA), indoleacetic acid (IAA), tryptophan (TRP) and skatole (IMD), respectively. This method could continuously perform extraction of ABA, GA, IAA, TRP and IMD from different concentrations of biogas slurry samples without complicated pretreatment avoiding lost, and then the extracts were analyzed by high performance liquid chromatography (HPLC). After optimized the analytical condition, a baseline separation of three plant hormones and two indole derivatives was accomplished within 35 mins. The results showed excellent linearity (R2 values of 0.9930-0.9999) and intra- and inter-day precisions (in the range of 3.8-7.2% and 3.9-7.5%), respectively. The limits of detection and quantification were in the range of 0.16-0.47 μg·mL-1 and 0.53-1.57 μg·mL-1, respectively. The determination performance was satisfactory with the proposed method. The results showed that the developed method was suitable for analysis of trace plant hormones in the biogas slurry.

Quantitative determination of plant hormones and derivatives in biogas slurry using on-line solid phase extraction with high performance liquid chromatography (On-Line SPE HPLC)

A novel method using on-line solid phase extraction coupled with high performance liquid chromatography (On-line SPE HPLC) was developed to measure three important plant hormones and two indole derivatives in the biogas slurry. These measured substances include abscisic acid (ABA), gibberellins (GA), indoleacetic acid (IAA), tryptophan (TRP) and skatole (IMD), respectively. This method could continuously perform extraction of ABA, GA, IAA, TRP and IMD from different concentrations of biogas slurry samples without complicated pretreatment avoiding lost, and then the extracts were analyzed by high performance liquid chromatography (HPLC). After optimized the analytical condition, a baseline separation of three plant hormones and two indole derivatives was accomplished within 35 mins. The results showed excellent linearity (R2 values of 0.9930-0.9999) and intra- and inter-day precisions (in the range of 3.8-7.2% and 3.9-7.5%), respectively. The limits of detection and quantification were in the range of 0.16-0.47 μg·mL-1 and 0.53-1.57 μg·mL-1, respectively. The determination performance was satisfactory with the proposed method. The results showed that the developed method was suitable for analysis of trace plant hormones in the biogas slurry.

Extraction and separation of low-concentration Ga (III) in concentrated hydrochloric acid using supported liquid membrane via controlling the dissociation behavior of GaCl4- ions at interface

A new approach using water as the stripping phase for extraction and recovery of low-concentration Ga (III) from concentrated hydrochloric acid solutions by Aliquat 336-based supported liquid membrane (SLM) is suggested. Generally, the stripping of Ga (III) from the loaded organic phase during liquid-liquid two-phase stirring extraction using quaternary ammonium salt as an extractant is extremely difficult. However, in the present work, an efficient mass transfer of low-concentration Ga (III) through the SLM was observed by introducing a low acidity (pH=2) aqueous solution as the stripping phase of the SLM. It was revealed that dissociation of GaCl4- and HCl2- anions into Ga3+, Cl- and H+ ions at the stripping/membrane phase interface play an important role in driving the mass transfer of GaCl4- from the concentrated hydrochloric acid solutions towards stripping phases. Kinetic analysis suggests that the permeability coefficient of Ga (III) ions through the SLM is dependent on the reaction temperature, extractant Aliquat 336 concentrations, and the difference in Cl- concentrations between the two sides of the liquid membrane phase, but independent of H+ concentrations. In view of future’s applications for selective separation and recovery of low-concentration Ga (III) from the concentrated hydrochloric acid leaching solutions of various gallium-containing solid wastes, separation selectivity of Ga (III) against other coexisting metal impurity ions, such as Fe (II), Al (III), Mg (II) and Cu (II), was also evaluated.

Energy-efficient leaching process for preparation of aluminum sulfate and synergistic extraction of Li and Ga from circulating fluidized bed fly ash

ABSTRACT Sequential leaching and extraction of precious metals from high aluminum (Al) circulating fluidized bed (CFB) fly ash in China, which associated with lithium (Li) and gallium (Ga), is one of the most significant ways for value-added utilization. However, industrial application has been limited due to serious corrosion of equipment, significant energy consumption, and complex purification processes. To sufficiently leach valuable metals from CFB fly ash, a novel energy-efficient sulfuric acid (H2SO4) leaching process using dilution heat was developed, and the effects of iron (Fe) amount in the raw materials on the extraction process of Al, Li, and Ga as well as the as-prepared Al-based products were studied to efficiently obtain the qualified aluminum sulfate (Al2(SO4)3) products. The leaching behavior of each target element was systematically investigated by the laboratory and pilot-scale experiments. The extraction efficiencies for Al, Li, and Ga were 95.2%, 94.2%, and 87.7%, respectively, when the acid leaching process was conducted at the temperature of 140°C for 2 h, with the H2SO4 concentration of 40% and the solid-to-liquid ratio of 1/3, In the Pilot-scale experiment, the temperature of the reaction system can reach 120°C, 140°C, and 160°C by regulating the amount of H2SO4 added to release different heat, and efficient leaching of the target elements was achieved by the energy-efficient sulfuric acid leaching process. To obtain qualified Al2(SO4)3 products from fly ash, carbothermal reduction magnetic separation, and acid leaching were used for Fe removal from raw fly ash, and the Fe content in the as-prepared Al2(SO4)3 products was only 0.45% and 0.29%, which reached the standards of Class II qualified products and Class II first-grade products, respectively. This paper might provide an energy-efficient process for efficient and high-value utilization of solid waste fly ash.

Mineralogy of Ga- and Ge-bearing metallurgical slags from Tsumeb, Namibia

AbstractGallium (Ga) and germanium (Ge) are technologically important critical elements. Lead blast furnace slags from Tsumeb, Namibia, comprise over two million metric tons of material that contains high levels of Ga (135–156 ppm) and Ge (128–441 ppm) in addition to significant Zn concentrations (up to 11 wt.%) and represent a potential resource for these elements. A combination of mineralogical and chemical methods (PXRD, FEG-SEM-EPMA and LA-ICP-MS) indicated different partitioning of Ga and Ge within the individual slag phases. Gallium is predominantly bound in small euhedral crystals of Zn–Fe–Al spinels (<10 μm in size), exhibiting concentrations in the range of 480–1370 ppm (up to 0.004 atoms per formula unit, apfu). Concentrations of Ga in other phases (e.g. melilite) are systematically below 90 ppm. The principal host of Ge is the silicate glass and, to a lesser extent, silicates (melilite and olivine group phases). Concentrations of Ge in glass attained a concentration of 470 ppm (EPMA), but the LA-ICP-MS analysis of glass matrix containing submicrometre spinel crystallites indicated that average Ge levels vary in the range of 113–394 ppm. In the potential extraction of Ga and Ge, the results indicate that ultrafine milling is needed to liberate the Ga- and Ge-hosting phases prior to metallurgical processing of the slag.

Extraction of Ga(III) by Di‐(2‐ethylhexyl)phosphoric acid (D2EHPA)‐Modified XAD‐4 Resins Prepared by Solvent‐Nonsolvent Modification

AbstractGallium (Ga) is one of the most important elements that are widely used in electronic devices. The development of Ga recovery technology is an important issue for resource recycling. In this study, di‐(2‐ethylhexyl)phosphoric acid (D2EHPA)‐modified XAD‐4 resin (DMR) is prepared by the solvent‐nonsolvent method. The evolution of pore characteristics demonstrates that the solvent‐nonsolvent treatment is advantageous for the immobilization of D2EHPA in XAD‐4 resin. The adsorption isotherm of Ga(III) can be described by the Langmuir isotherm model. The Ga(III) adsorption kinetics follows the pseudo‐second‐order model. The immobilized D2EHPA shows good stability. The reusability study indicates that DMR can maintain the performance after three cycles of adsorption and stripping. The results for the treatment of a practical leaching solution from GaN/Al2O3 wafer further demonstrate that DMR can be applied effectively for Ga(III) recovery.

Recovery of gallium from sulfuric acid leach liquor of coal fly ash by stepwise separation using P507 and Cyanex 272

For the ever-growing demand of gallium (Ga) resources in electronic applications, the recovery of Ga from the mining residues or waste has received considerable interest. The present paper is focused on the selective recovery of Ga from the sulfuric acid leach liquor of coal fly ash (CFA) by stepwise separation using acidic extractant. The results show that Ga(III) can be effectively separated by controlling the equilibrium pH values and meanwhile employing appropriate extractant based on the different ionic potential and electronic configuration of metal ions. At equilibrium pH ≤ 0.8, the impurities Ti(IV) and Fe(III) in the liquor can be preferably removed by a two-stage cross current extraction with 1 mol/L P507. Then Ga(III) can be selectively separated against Al(III) using 0.5 mol/L Cyanex 272 at equilibrium pH of 2.4–2.6. The separation factors of Fe/Ga, Fe/Al and Ga/Al can reach 145, 133 and 40, respectively. The extraction mechanism of Ga(III) as well as the Ga(III) complexes with Cyanex 272 were investigated using slope analysis and spectroscopic methods including FT-IR, NMR and ESI-MS, indicating that the extraction of Ga(III) with Cyanex 272 follows an ion exchange mechanism. The Ga(III) complexes with Cyanex 272 (H2L2) contains three coordination compounds, GaL3, Ga(HL)L3 and Ga(HL)3L3. Both the P-O and P = O groups of Cyanex 272 play the roles in the coordination reaction of Ga(III). The study provides a feasible way for the selective recovery of Ga from coal fly ash.

Separation of Radiogallium from Zinc Using Membrane-Based Liquid-Liquid Extraction in Flow: Experimental and COSMO-RS Studies

ABSTRACTA switch from batch to continuous manufacturing of gallium-68 (68Ga) and 68Ga-labeled pharmaceuticals can be advantageous, as it recycles isotopically-enriched zinc-68 (68Zn), removes pre- and post-irradiation target manipulations, and provides scalability via dose-on-demand production. Herein we report efficient extraction of radiogallium (66,67,68Ga = *Ga) from ZnCl2/HCl solutions in batch and in flow using a membrane-based liquid-liquid separator. From 5.6 M ZnCl2/3 M HCl, a 1/2 (v/v) diisopropyl ether (iPr2O)/trifluorotoluene (TFT) solvent extracts 76.3 ± 1.9% of *Ga and 1.9 ± 1.6% of Zn in flow using a single pass through. From 1 M ZnCl2/6 M HCl, a 1/2 (v/v) n-butyl methyl ether (n-BuOMe)/TFT solvent extracts 95.7 ± 2.0% of *Ga and 0.005 ± 0.003% of Zn in flow. TFT plays a key role in controlling the interfacial tension between the aqueous and the organic phases, ensuring clean membrane-based separation. The process did not extract Cu, Mn, and Co but did extract Fe. Using HGaCl4 and ZnCl2 as the extractable species, the COSMO-RS theory predicts the solvation-driven extraction of Ga and Zn with a mean unsigned error of prediction of 4.0% and 3.4% respectively.

Mechanochemical Synthesis of Intermetallic Compounds in the Gallium–Iridium System

The interaction between a solid inert metal Ir and an active liquid metal Ga during mechanical activation in a high-energy planetary mill is studied by X-ray diffraction and scanning electron microscopy with high-resolution energy dispersive X-ray microanalysis. The effect of mechanical activation on the formation of GaxIry intermetallic compounds and GaxIry/Ir composites and their solubility in acids was investigated. The subsequent extraction of Ga from intermetallic compounds and composites in the mixture of concentrated acids [Formula: see text] makes it possible to produce nanoscale Ir.

Recovery of Ga(III) from chloride solutions by solvent extraction with Cextrant 230

In the present work, an α-aminophosphonate extractant di(2-ethylhexyl) [N-(2-ethylhexyl)aminomethyl] phosphonate (Cextrant 230, L) was applied for the selective extraction and recovery of Ga(III) from the chloride solutions. The extraction of Ga(III) was compared with that of other metal ions such as Fe3+, Fe2+, Zn2+, Al3+, Mg2+ and Sn2+. The extracted complex of Ga(III) was deduced to be HGaCl4·L. The extraction equilibrium constant and thermodynamic parameters (ΔG, ΔH and ΔS) were calculated. The positive value of ΔH indicates that the extraction reaction of Ga(III) is an endothermic process. The loading capacity of 30% (v/v) Cextrant 230 for Ga(III) was determined to be 0.38 mol/L. The loaded gallium can be complete stripped by distilled water. A process was established for the selective recovery of Ga(III), by which the purity of the gallium product reached 94% with a yield of 89.5%