Sulfate Leach Liquor Research Articles

Recovery of Pure Co(II) and Ni(II) Solutions from Synthetic Sulfate Leach Liquor of Laterite Ores by Precipitation and Solvent Extraction

ABSTRACT Recovery of nickel and cobalt from laterite ores is important to meet the demand for these metals. In this work, a process was developed for the separation of metal ions from synthetic sulfate leach liquor of laterite ores containing Fe(III), Al(III), Ni(II), Co(II), Ca(II), Mg(II), and Mn(II). First, Fe(III) and Al(III) were removed by precipitation of their hydroxides by adjusting solution pH and then Mn(II) was removed from the filtrate by oxidative precipitation with NaClO. Sequentially, Co(II) and Ni(II) from the filtrate containing Mg(II) and Ca(II) were separated by selective precipitation of CoS and NiS by adding Na2S solution, leaving Ca(II) and Mg(II) in the filtrate. The mixed precipitates of CoS and NiS were completely dissolved by 0.1 M HCl solution containing NaClO. Co(II) can be separated from Ni(II) present in the HCl solution by either oxidative precipitation with NaClO or selective extraction with saponified Cyanex 272. Optimum conditions for these procedures were obtained. Continuous experiments indicated that the purity of Co(II) and Ni(II) solutions was higher than 99%.

Uranium (VI) sorption from aqueous solution using commercial anion exchange resins; kinetics, isotherm, and thermodynamic investigations

Commercial strong anion exchange resins provided by Purolite, namely MTA4801PF, and MTA4601PFSO4, were utilized for extracting uranium from sulfate leach liquor. The study focused on investigating the kinetics, isotherms, and thermodynamics of the sorption process. Both resins demonstrated similar kinetics and isotherm performance, with sorption capacities of approximately 66 and 71 mg g−1 respectively. The sorption process was proven to be endothermic, feasible, and spontaneous, and U(VI) desorption of around 95% was achieved using 0.5 M sulfuric acid. Commercial resins showed excellent sorption performance when applied to sulfate leach liquor of Egyptian ores despite the complexity of the solution.

Dithiocarbamate functionalised crosslinked polyacrylamide for separation and pre-concentration of uranium (VI) ions from sulphate medium

ABSTRACT This article introduces a novel approach for extracting and concentrating uranium (VI) ions from water-based solutions using two dithiocarbamate functionalised cross-linked polyacrylamide adsorbents, CPAAm-DETA-CS2 and CPAAm-EDA-CS2. The adsorbents were synthesised and characterised through techniques like Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and elemental analysis. The efficacy of these adsorbents in removing U(VI) species from solution matrices was systematically investigated, yielding maximum adsorption capacities of approximately 57.8 mg/g and 60.2 mg/g for CPAAm-EDA-CS2 and CPAAm-DETA-CS2, respectively. The optimised operational parameters encompassed a solution pH of 4.0, a contact period of 60 minutes, and an adsorbent dosage of 1.7 g/L, all conducted at ambient temperature. The adsorption adhered to the Langmuir isotherm and pseudo-second order kinetics, with a spontaneous and exothermic nature. Notably, the adsorbents displayed potential for regeneration and reuse. CPAAm-DETA-CS2 sorbent which exhibits the highest sorption capacity was applied successfully for the removal of uranium(VI) removal from sulphate leach liquor of Sella uranium ore. The adsorption capacity of the prepared sorbent was ≈ 45.3 mg/g. These aforementioned findings underscore the viability of a sustainable approach for uranium extraction, highlighting the notable importance of dithiocarbamate functionalised cross-linked polyacrylamide as a proficient adsorbent within the realm of environmental and industrial uranium separation processes.

Hydrometallurgical recovery of critical metals from an incinerated fly ash of municipal solid waste from western India

ABSTRACT The global generation of 2.2 billion tons of municipal solid waste (MSW) as a result of population growth, rapid urbanization, and industrial development has highlighted an urgent need for MSW management. Incineration is widely accepted as one alternative to landfilling; however, the recovery of heavy metals from the incinerated fly ash (IFA) before its final disposal is highly desirable to make the process sustainable. In this study, we studied the recovery of zinc and lead from typical MSW-IFA employing hydrometallurgical techniques. Sulfuric acid leaching was performed to selectively leach out zinc over the lead at the optimal condition of H2SO4 concentration = 1.5 M, temperature = 30°C, S/L ratio = 150 g/L, time = 2 h, and stirring speed = 300 rpm. The sulfate leach liquor was treated with a 5% stoichiometric excess of oxalic acid to precipitate>99% of zinc to be recovered as ZnC2O4·2 H2O. Further, the remaining lead in leach residue was subsequently leached in 50 g/L NaCl solution for 2 h yielded>94% efficiency. The dissolved lead was crystallized to recover the crystals of PbCl2. The demonstrated process leads towards the recovery of critical metals from an alternative source of MSW-IFA.

Ecological treatment of El Kriymat boiler ash for recovering vanadium, nickel and zinc from sulfate leach liquor

The primary goal of this work is to develop a technology that allows for the recovery of metal values from waste products, thereby promoting the wise and efficient use of our nation's resources. To achieve this goal, an industrial waste of El Kriymat boiler fly Ash was used for recovering its content of vanadium, nickel and zinc. About 97, 95 and 99% respectively of these economic elements were first dissolved from boiler fly ash magnetic concentrate (after physical concentration). Leaching experiments using optimum conditions include: 180 g/L sulfuric acid concentration and 4% solid/solid proportion manganese dioxide acts as an oxidant at 80 °C. The recovery of vanadium (V) metal ions was carried out using 3% Alamine 336 in kerosene at an equilibrium pH value of 0.9. Subsequently, 15% sodium sulfide solution was used for co-precipitation of nickel and zinc metal ions in the raffinate solution at pH value of 3.5.Graphical

Experimental study on the uranium(VI) extraction rate and droplet mass transfer coefficients from a sulfate leach liquor medium with Alamine 336 in a single drop column

Experimental study on the uranium(VI) extraction rate and droplet mass transfer coefficients from a sulfate leach liquor medium with Alamine 336 in a single drop column

Sequential separation and selective extraction of uranium and thorium from monazite sulfate leach liquor using dipropylamine extractant

Monazite mineral is the main source of uranium and thorium, which are mainly associated with rare earth elements (REEs). So, their separation is the crucial task to satisfy their application for nuclear fuel. Dipropylamine was used for the first time in the selective extraction and separation of uranium and thorium from Monazite sulfate leach liquor. The extraction of thorium (98%) was achieved using dipropylamine in kerosene at pH 1; it was followed by selective extraction of uranium (97%) by Dipropylamine at pH 3. The thermodynamic analysis demonstrated that uranium (VI) and thorium (IV) extraction by dipropylamine is an exothermic process. From the stripped liquor (1 M H2SO4), Th and U were precipitated as oxalate and peroxide, respectively, for technological application. Thus, marketable pure thorium and uranium products were prepared in addition to rare earth concentrate.

Recovery of Uranium from Sulfate Leach Liquor Using Natural Orange Peel Extractant

Recovery of Uranium from Sulfate Leach Liquor Using Natural Orange Peel Extractant

Recovery of cobalt and nickel from magnesium-rich sulfate leach liquor with magnesium oxide precipitation method

Nickel, cobalt, and magnesium often coexist in the sulphate leach liquor of laterite nickel ores, and magnesium will affect the following refining process of nickel and cobalt. In this paper, magnesium oxide slurry was employed to precipitate and separate nickel and cobalt from magnesium with the precipitation method. The appropriate conditions to maximize the precipitation of nickel and cobalt and minimize the precipitation of magnesium are investigated systematically as follows: magnesium oxide addition (nMgO: (nNi + nCo)) = 2.0, hydrolysis time ≤ 2 h, hydrolysis temperature ≥ 60 °C, and stirring speed ≤ 350 rpm. The equilibrium pH, which can be controlled by adjusting the amount of magnesium oxide and temperature, was found to be the main influence factor, and the optimal equilibrium pH of the sulphate leach liquor should be controlled at 8.98. The high precipitations of 98.1% for nickel and 99.1% for cobalt can be obtained with low precipitation of 0.2% for magnesium. The characterizations of the mixed precipitate by XRD, FTIR, and TG–DTG demonstrate the presence of Ni2(CO3)(OH)2 and NiSO4·2H2O except for the primary Ni(OH)2 and Co(OH)2. The nickel and cobalt in the precipitate can be easily transferred into the low acidic solution by leaching at ambient temperature. The regenerated magnesium oxide powder with a high purity can be obtained by calcining the precipitates, which can be recycled as the precipitating agent again.

Electrosynthesis of titanium dioxide from sulfate leach liquors using solvent extraction/electrochemical deposition process

ABSTRACT The primary goal of this study was the development of a recycling process to recover titanium from real sulfate leach liquors prepared from the tailings of uranium processing mine. Preparation and characterization of pure TiO2 powders using; a clean, cheap, and low-temperature combined solvent extraction/electrochemical deposition technique were reported. Solvent extraction using di(2-ethylhexyl) phosphoric acid in kerosene allowed the selective recovery of Ti (IV) from the leach liquor containing Fe, Mn, and Zr impurities. All of the Ti was extracted selectively using 20% D2EHPA/kerosene under organic/aqueous phase ratio of unity in presence of L-ascorbic acid. The equilibrium in 8.5 M sulfuric acid is established within 60 min. Subsequently, Ti was recovered from the loaded organic phase using mixtures of HCl and H2O2 solutions. The preparation of TiO2 powders by cathodic electrodeposition was optimized. A combination of X-ray diffraction and dynamic light scattering analysis had been used to confirm the formation of TiO2 nanoparticles. Finally, the solvent extraction and electrodeposition mechanisms were discussed, and the resultant products were characterized by several techniques.

Adsorption of uranium (VI) from acidic leach liquor using Amberlite IRA-400 impregnated with amines

Amberlite IRA 400 was impregnated with N, N’, N’-Tetramethylethylenediamine (ATMEDA) as well as N-Methyl benzyl amine (AMBA) and examined for uranium uptake efficiency from sulfate medium. The potential of the studied adsorbents for uranium uptake was evaluated at different conditions; the effect of aqueous uranium concentration, contact time, pH value, temperature variation, amount of added adsorbent and matrix competitive ions. The implication of adsorption isotherms for (Amberlite IRA 400), (AMBA) and (ATMEDA) revealed that the results correlate with the Langmuir isotherm model with 90.90, 181.81 and 196.07 mg/g as theoretical capacity. Uranium adsorption kinetics was studied using Lagergren pseudo-firrst order, pseudo-second-order, Elovich and intra-particle diffusion models. Studied kinetics revealed that the process corresponds to the pseudo-second-order model. Optimum conditions were applied for uranium (VI) recovery from sulfate leach liquor of cataclastic rocks, Abu-Rusheid, south Eastern Desert, Egypt. The final uranium precipitate was characterized using ICP-OES, XRF and EDX.

Studying the Effect of Potassium Amyl Xanthate Surfactant on Fe, Cu and U Ions for the Pretreatment of Abu Zeneima Sulphate Leach Liquor

In this study, batch experiments were performed to study the behavior of potassium amyl xanthate surfactant on Fe, Cu and U ions for the pretreatment of Abu Zeneima sulphate leach liquor. Various parameters, such as amount of potassium amyl xanthate, pH, stirring time, sample volume to potassium amyl xanthate mass (v/m ratio) and temperature were tested to determine the optimum conditions. The numerical results obtained support the experimental data on decreasing the iron and copper values where 0.1 g potassium amyl xanthate could remove 86.8 mg Fe and 0.98 mg Cu from the studied sulphate solution with no effect on uranium content. FTIR spectroscopy and XRF analysis were used for investigation.

Studies on uranium extraction from leach liquor of the mineralized shear zone at El-Missikat area using tri-n-octylamine

Fast extraction of uranium from Egyptian low-grade uranium mineralization sulfate leach liquor was studied with kerosene solutions of tri-n-octylamine (TOA). The parameters affecting uranium extraction were studied and the optimum conditions were determined. The equilibrium isotherm demonstrated the association of four moles of TOA per mole of uranium. Thermodynamic studies at different temperatures indicated that the extraction process was exothermic, favorable and spontaneous in nature. The organic phase loaded with uranyl sulfate under the optimum extraction conditions were examined by infrared spectrometry. The McCabe–Thiele plot for circuit of uranium with TOA predicted three extraction stages and two stripping stages.

Effect of zinc ions on copper electrodeposition in the context of metal recovery from waste printed circuit boards

This paper evaluates the effect of zinc ions on copper electrodeposition. Although zincis not found at significant concentrations in conventional industrial copper electrolytes, in copper-concentrated sulfate leach liquors produced in the treatment of waste printed circuit boards (WPCB) its concentration may reach high levels. In this context, the effect of zinc on physical-chemical properties of copper sulfate electrolyte, performance indicators of copper electrowinning, and morphology and crystal structure of copper deposits were investigated. Copper electrowinning tests indicated that the current efficiency was negligibly affected by adding zinc (up to 75 g L−1) to synthetic copper sulfate electrolyte (30 g L−1 Cu2+ and 110 g L−1 H2SO4) at two levels of current density (250 A m−2 and 450 A m−2) and fixed temperature (35 °C). The energy consumption slightly increased: up to 4% at 250 A m−2 and up to 3% at 450 A m−2, both effects at 75 g L−1 Zn2+. This behavior was ascribed to decreases in the electrical conductivity of the electrolyte by adding zinc (up to 35% at 75 g L−1) and consequent increases in the ohmic drop and cell voltage. Electrochemical measurements by cyclic voltammetry and linear sweep voltammetry (LSV) indicated no cathode polarization by adding this impurity to the electrolyte, even at the highest level. In turn, the addition of zinc caused significant drops in the limiting current for copper deposition (e.g., the values recorded at 100 min−1 decreased about 60% when 75 g L−1 Zn2+ was added to the electrolyte). This effect was explained by the measured increases of electrolyte viscosity and calculated decreases of copper diffusion coefficient. The addition of 75 g L−1 Zn2+ to the electrolyte increased its viscosity in the order of 76%, and decreased the diffusion coefficient in the order of 45%. Regarding the effect of zinc on product quality, SEM analysis revealed negative effects on the morphology of the deposits (i.e., higher roughness and nodulation), mainly at the highest concentration of zinc and highest current density. XRD analysis showed modifications in the growth pattern of copper crystals under some conditions. For example, the addition of 30–75 g L−1 Zn2+ to the electrolyte led to the formation of (220) textured deposits at 250 A m−2. The findings of this work may be helpful to define proper operating conditions for copper electrowinning in order to produce high quality products, thus maximizing the recycling of copper from the selected secondary source.

Extraction equilibria of cerium(IV) with Cyanex 923 followed by precipitation kinetics of cerium(III) oxalate from sulfate solution

The phenomenon studies on solvent extraction of cerium(IV) using Cyanex 923 followed by the precipitation kinetics and recovery of cerium(III) oxalate has been investigated from the sulfate media. The extraction equilibria investigated with varying concentrations of extractant into the organic phase and acid into the aqueous phase could reveal the solvation of [Ce(SO4)2·2L·HSO4-]org species. The thermodynamic properties determined at different temperatures exhibited the exothermic nature of extraction (ΔH°, −12.2 kJ·mol−1). The quantitative extraction and back-extraction of cerium(IV) in sulfate media could be achieved in three stages of counter-current contact at an organic-to-aqueous ratio of 2/3 and 3/2, respectively. Ce-enrich stripped solution was subsequently recovered as cerium(III) precipitates by treating with oxalic acid. Precipitation with the optimized dosage of Ce:H2C2O4 as 1:≥10 yielded the oxalate products of unlike physico-chemical characteristics, while precipitating at different temperatures. The precipitation kinetics was found to have good fits to the Avrami equation; where, n values < 1 indicated for instantaneous nucleation that leads to flakes-shape growth of precipitates and supported by the surface morphological study. Evaluation of the apparent activation energy (Ea, 8.6 kJ·mol−1) indicated that the precipitation reaction follows a diffusion-controlled mechanism as supported by the surface site saturation of cerium(III) oxalate through the constants of Avrami equation. The findings of the present study may supply a potential way of extracting cerium(IV) from sulfate leach liquor of rare earths ores and the precipitation recovery of cerium(III) oxalate as the suitable precursor of (nano)crystalline ceria.

Cleaner production of rare earth elements from phosphorus-bearing sulfuric acid solution of vein deposit monazite

In the present study, the recovery of rare earth elements (REEs; viz. cerium, lanthanum, and yttrium) from sulfate leach liquor of vein deposit Korean monazite has been investigated using the solvo-chemical techniques. The dissolved phosphorus (373 mg L−1), which may significantly affect the products’ purity, was selectively removed using the benzyl-di-methyl amine (BDMA). The logarithmic distribution vs. BDMA concentration along with spectral analysis of the organic phases revealed the formation of extracted species 3[BDMA].[H3PO4]¯. The quantitative removal of phosphorus was achieved in three stages of counter-current extraction (CCE) under the organic-to-aqueous (O:A) ratio of 1.0:1.5, leaving REEs’ into the raffinate. Subsequently, Cyanex 923 was employed to selectively extract cerium(IV) from P-depleted solution under the varying parameters of extractant and sulfuric acid concentration, temperature, and O:A ratio. The quantitative extraction of cerium (∼99% from 864 mg L−1 feed concentration) showing exothermic nature was achieved at an O:A of 1:2 under three stages of CCE while using 0.15 mg L−1 extractant into organic phase and 1.12 mol L−1 H2SO4 into aqueous phase. Further, the experimental results and spectral analysis of the organic phases could reveal that cerium solvates as [Ce(SO4)2].2[Cyanex 923].[HSO4−]¯ species. Cerium was successfully stripped from loaded organic by contacting with a higher concentration of H2SO4 solution (≥4.0 mol L−1) in presence of 0.1 mol L−1 H2O2, yielding an enriched high-purity solution of 2.54 g L−1 cerium. Lanthanum and yttrium were recovered from the Ce-depleted raffinate by co-precipitation with oxalic acid, forming a mixture of C6La2O12.10H2O and C6Y2O12.4H2O. The study approaches a cleaner production of high-purity REEs for clean energy programs under Sustainable Development Goals.

An Investigation into the Extraction Behavior of Copper from Sulfate Leach Liquor Using Acorga M5640 Extractant: Mechanism, Equilibrium, and Thermodynamics

The extraction of copper from sulfate leaching liquor was investigated using Acorga M5640 commercial extractant in kerosene diluent. The effects of important factors such as the extractant concentration, contact time, liquor pH, and temperature were examined on the separation factor Cu/Fe and the extraction efficiency of copper. The results indicated that nearly 92.32% copper was extracted from the leach liquor at 10% (v/v) Acorga M5640 concentration, 1:1 aqueous/organic phase ratio, 20 min contact time, pH 2.5, and 25 °C temperature. Also, the further increase in the values determined had no positive impact on the extraction of copper. Under these conditions, the separation factor Cu/Fe was obtained about 29.64. The extraction mechanism was studied applying the plot of log(D) – 2 pH against log [extractant] and it proved the association of two moles of Acorga M5640 for the extraction of one mole of copper. McCabe–Thiele diagram was constructed and a single-step extraction process was found to obtain the maximum extraction. Additionally, thermodynamic data were investigated and the extraction process was endothermic and non-spontaneous at 298 K (ΔH = 27.05 and ΔG = 15.52 kJ mol−1). Moreover, the loaded organic phase was stripped and 80.94% copper was recovered after 20 min using 10% sulfuric acid concentration.

Sorption behavior of uranium from Sulfate media using purolite A400 as a strong base anion Exchange resin

ABSTRACT The sorption characteristics of uranium onto a strongly basic anion exchanger, Purolite A400, were investigated. The characteristics of Purolite A400, before and after sorption of uranium, were determined using scanning electron microscopy (SEM) and energetic-dispersive X-ray (EDX). The influence of the different parameters, which may affect the process of uranium sorption process, had been tracked. Specifically, impacts of initial uranium concentration, pH, contact time and temperature, on uranium removal, were studied. In addition, the sorption kinetics and equilibrium parameters were assessed. At the optimum conditions, the adsorption capacity of uranium was found to be nearly 117.6 mg/g. The kinetics and isotherm studies could show that the uranium sorption onto Purolite A400 is following the models of pseudo-second-order and Langmuir isotherm respectively. The thermodynamic parameters had indicated that the adsorption of uranium is an exothermic and spontaneous process. The detected results of uranium sorption could reveal that Purolite A400 is a suitable material for pre-concentration of uranium (VI) species from sulfate leach liquor.

Evaluation of uranium adsorption using magnetic-polyamine chitosan from sulfate leach liquor of Sela ore material, South Eastern Desert, Egypt

Chitosan particles with magnetic properties were prepared by co-precipitation method combined with hydrothermal treatment, then crosslinked with epichlorohydrin followed by grafting of triethylenetetramine. The obtained adsorbent material was characterized by means of FTIR and XRD and its adsorption properties towards uranyl ions were firstly investigated from synthetic solutions as a function of pH, contact time and initial uranium concentration using batch method and at room temperature. The maximum adsorption capacity was found to be158.43 mg/g at pH 4 and initial uranium concentration of 300 mg/l. Urea solution of 0.5 mol/l acidified with a few drops of sulfuric acid 0.2 mol/l can be efficiently used for uranium recovery and the adsorbent can be recycled for at least five successive cycles with limited decrease in adsorption performance. Subsequently, the application efficiency of the adsorbent material was evaluated by testing uranyl adsorption from sulfate leach liquor of Sela ore material after adaptation of leaching conditions. Uranium ore sample was subjected to acid conventional leaching through direct agitation with sulfuric acid and the relevant variables affecting leaching efficiency were optimized as 60 g/l sulfuric acid with liquid/solid weight ratio 3 at 45 °C for 90 minutes. Under these conditions, the leaching efficiency of uranium was 92%. Uranium adsorption capacity from sulfate leach liquor was found to be 132.98 mg/g at pH 4 and shaken time of 60 minutes with initial uranium concentration of 200 mg/l. This adsorption capacity represents only about 87% from the adsorption ability from synthetic solutions (152.86 mg/g) at the same conditions.

Recovery of Uranium(VI) from Sulfate Leach Liquor using Modified Duolite

Silicate mercapto Duolite composite (SMDC) and activated Duolite A 101 D (AD) were prepared, characterized, and tested for uranium removal from sulfate solution using batch experiment technique. The capability of newly adsorbents for sorption of uranium was estimated and optimized under different controlling variables, including the impact of uranium initial concentration, pH of the medium, equilibrium time, temperatures, dose and interfering ions. Testing of different adsorbents for adsorption isotherms revealed that the achieved experimental data were fitting well with the Langmuir isotherm model with 68.02 mg·g–1 and 208.33 mg·g–1 as theoretical capacity for AD and SMDC, respectively. Thermodynamic parameters have been resulted in negative values for ΔH and ΔS indicating an exothermic and decreased randomness behavior for uranium(VI) adsorption, while negative values of ΔG indicate spontaneous uranium adsorption. The kinetics studies showed that the adsorption process was controlled expressed by pseudo‐second order model. Finally, the optimized factors have been applied for uranium(VI) recovery from Gattar leach liquor producing a uranium concentrate (Na2U2O7) with uranium concentration of 70 % and purity of 93.33 %.