scholarly journals Separation of Aluminum and Iron from Lanthanum—A Comparative Study of Solvent Extraction and Hydrolysis-Precipitation

Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 556
Author(s):  
Adam Balinski ◽  
Norman Kelly ◽  
Toni Helbig ◽  
Christina Meskers ◽  
Markus Andreas Reuter
Keyword(s):  
Solvent Extraction ◽  
Organic Phase ◽  
Ph Value ◽  
Naphthenic Acid ◽  
Complete Removal ◽  
Sulfate Solution ◽  
Aluminum Concentration ◽  
Precipitation Method ◽  
Strong Increase ◽  
Ph Range

This study investigates the removal of aluminum and iron from rare earth element (REE) containing solutions by solvent extraction with saponified naphthenic acid and by hydrolysis-precipitation. The results emphasize both, the preferential application as well as limitations of every method. We find that emulsification occurring during the solvent extraction of aluminum is caused by its slow extraction rate in comparison to the neutralization reaction and by the proximity of the pH value required for aluminum extraction and the pH value at which hydrolysis of aluminum occurs. However, by choosing a long shaking time of at least 4 h, the emulsion recedes. The formation of emulsion can be avoided by strict control of pH value during the extraction. Moreover, the loading capacity of the organic phase with aluminum is limited due to the strong increase in viscosity of the organic phase with increasing aluminum concentration and due to the gel formation. Regarding the extraction of iron, the amount of extracted ions is limited due to the overlap of the pH range required for the extraction with pH range in which sparingly soluble iron oxides/hydroxides are formed. In summary, aluminum and iron can be simultaneously removed from REE-sulfate solution by solvent extraction with saponified naphthenic acid in one extraction stage only from diluted solutions. However, in comparison to the hydrolysis-precipitation method, a higher purity of the solution is achieved. A complete removal of aluminum and iron from concentrated solutions can be achieved in two stages. First, the content of aluminum and iron should be reduced by hydrolysis-precipitation. After that, a high-purity solution can be obtained by subsequent solvent extraction by saponified naphthenic acid.

Kinetics of solvent extraction of metal ions with HEDHP. III. The kinetics and mechanism of solvent extraction of Cr(III) from acidic aqueous solutions with bis-(2-ethyl hexyl) phosphoric acid in benzene

1979 ◽  
Vol 57 (23) ◽  
pp. 3011-3016 ◽  
Author(s):  
Muhammad Fakhrul Islam ◽  
Ranjit Kumar Biswas
Keyword(s):  
Solvent Extraction ◽  
Phosphoric Acid ◽  
Aqueous Phase ◽  
Organic Phase ◽  
Forward Rate ◽  
Nitrate Ions ◽  
Rate Determining Step ◽  
Ethyl Hexyl ◽  
Ph Range ◽  
Kinetics Of

The rate of solvent extraction of chromium(III) from aqueous sulphuric acid solutions (containing 0.05 mol dm−3 sulphate ion and 0.25 mol dm−3 acetate buffer, ionic strength, I = 0.40 mol dm−3) with bis-(2-ethyl hexyl) phosphoric acid (HDEHP or H2A2) in benzene has been measured under various conditions. The rate of backward extraction measurement of Cr(III) from organic phase to aqueous phase is not possible due to the inert property of Cr(III)–DEHP chelate. The forward rate is found to be first-order w.r.t. Cr(III) concentration in the aqueous phase and HDEHP concentration in the organic phase. The order w.r.t. H+ concentration varies from −1 to 1 over the pH range 1.5 to 5.25. The rate is found to decrease with increasing sulphate and nitrate ions concentrations in the aqueous phase. At (30 ± 1) °C, the rate expression, in the presence of sulphate, acetate, and nitrate ions, is found to be represented by:[Formula: see text]In the absence of the anions, the formation of CrHA22+ intermediate complex (Cr(OH)2+ + H2A2(0) → CrHA22+ + H2O) is the rate determining step at all acidities. The effects of the anions on the rate are discussed.

scholarly journals Liquid-liquid separation of Cd (II) from Cu-sulfide cake prepared from sulfate solution of Abu-Thor ore material, Southwestern, Sinai, Egypt

2021 ◽  
Vol 11 (3) ◽  
pp. 229
Author(s):  
Elham Awny
Keyword(s):  
Aqueous Phase ◽  
Organic Phase ◽  
Contact Time ◽  
Ph Value ◽  
Sulfate Solution ◽  
Liquid Ratio ◽  
Liquid Separation ◽  
Extraction Parameters ◽  
Solid Liquid ◽  
Southwestern Sinai

The present work is concerned with the subsequent liquid-liquid separation of Cu, Zn, and Cd compounds from Cu- sulfide cake prepared from the sulfate solution of Abu-Thor Gibbsite-bearing shale ore material. This ore was found assaying 0.014% of Cd, 0.5% of Cu, and 0.55% of Zn as the elements of interest, by using 25% of H<sub>2</sub>SO<sub>4</sub> solution at a solid/liquid ratio of 1/3 reaction time of 90 min at a temperature of 80<sup> </sup>◦C. About 96.5% of Cu (II), 99.3% of Cd (II), and 95.6% of Zn (II), respectively, were dissolved. After filtration, the prepared sulfate solution was treated with a suitable weight of Na<sub>2</sub>S to prepare the working Cu-sulfide cake, which was then wholly re-dissolved in 10% of H<sub>2</sub>SO<sub>4</sub> solution to prepare the working sulfate solution, which contained the elements of interest. This solution was gone out to the organic solvent process for complete separating between the Cu (II), Zn (II) ions in the organic phase, and Cd (II) ions in the aqueous phase. The effective extraction parameters such as pH value, LIX concentration, contact time, and organic/aqueous ratio were studied. The obtained data cleared that the pH value of 2.5 was found effective for separating Cd (II) in the aqueous phase and both Zn (II) and Cu (II) in the organic phase. Where Cd (II) ions were precipitated as CdS using Na<sub>2</sub>S solution at pH 0.89, on the other side, both Zn (II) and Cu (II) were completely separated in the stripping process using Na<sub>2</sub>CO<sub>3</sub> solution.

Synthesis and Characterization of LiNixCoyMn1-x-yO2 as a Cathode Material for Lithium Ion Batteries

2007 ◽  
Vol 280-283 ◽  
pp. 677-682 ◽  
Author(s):  
Pei Yun Liao ◽  
Jenq Gong Duh
Keyword(s):  
Cathode Material ◽  
Cathode Materials ◽  
Ph Value ◽  
Lithium Ion ◽  
Sulfate Solution ◽  
Hexagonal Structure ◽  
Precipitation Method ◽  
Future Application ◽  
Metal Sulfate ◽  
Voltage Range

The newly developed LiNi0.6Co0.4-xMnxO2 (0.1 < x < 0.3) cathode materials were synthesized by calcining the mixture of NixCoyMn1-x-y(OH)2 and Li2CO3 at 900-940 oC for 15 hr in flowing O2 atmosphere. The NixCoyMn1-x-y(OH)2 precursor was obtained by the chemical co-precipitation method at the pH value controlled by the concentration of NaOH, NH4OH and transition metal sulfate solution. The X-ray diffraction patterns indicated the pure layered hexagonal structure LiNi0.6Co0.4-xMnxO2. The electrochemical behavior of LiNixCoyMn1-x-yO2 powder was examined by using test cells cycled within the voltage range 3-4.3 V at the 0.1C rate for the first cycle and then at the 0.2C rate afterwards. LiNixCoyMn1-x-yO2 cathode materials showed good initial discharge capacity (165-180 mAh/g) and cycling performance. The fading rate was less than 5 % after 20 cycling test. It is demonstrated that LiNixCoyMn1-x-yO2 electrode should exhibit great potential for the future application in lithium-ion battery cathode material.

scholarly journals Study on the Effect and Mechanism of Impurity Aluminum on the Solvent Extraction of Rare Earth Elements (Nd, Pr, La) by P204-P350 in Chloride Solution

Minerals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 61
Author(s):  
Wenjie Zhang ◽  
Xian Xie ◽  
Xiong Tong ◽  
Yunpeng Du ◽  
Qiang Song ◽  
...  
Keyword(s):  
Rare Earth ◽  
Solvent Extraction ◽  
Rare Earth Elements ◽  
Organic Phase ◽  
Extraction Process ◽  
Industrial Applications ◽  
Separation And Purification ◽  
Aluminum Ion ◽  
Hydrochloric Acid Medium ◽  
Impurity Ion

Solvent extraction is the most widely used method for separation and purification of rare earth elements, and organic extractants such as di(2-ethylhexyl) phosphoric acid (P204) and di(1-methyl-heptyl) methyl phosphonate (P350) are most commonly used for industrial applications. However, the presence of impurity ions in the feed liquid during extraction can easily emulsify the extractant and affect the quality of rare earth products. Aluminum ion is the most common impurity ion in the feed liquid, and it is an important cause of emulsification of the extractant. In this study, the influence of aluminum ion was investigated on the extraction of light rare earth elements by the P204-P350 system in hydrochloric acid medium. The results show that Al3+ competes with light rare earths in the extraction process, reducing the overall extraction rate. In addition, the Al3+ stripping rate is low and there is continuous accumulation of Al3+ in the organic phase during the stripping process, affecting the extraction efficiency and even causing emulsification. The slope method and infrared detection were utilized to explore the formation of an extraction compound of Al3+ and the extractant P204-P350 that entered the organic phase as AlCl[(HA)2]2P350(o).

scholarly journals Separation of Sn, Sb, Bi, and Cu from Tin Anode Slime by Solvent Extraction and Chemical Precipitation

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 515
Author(s):  
Wei-Sheng Chen ◽  
Shota Mesaki ◽  
Cheng-Han Lee
Keyword(s):  
Solvent Extraction ◽  
Liquid Phase ◽  
Ph Value ◽  
Chemical Precipitation ◽  
Extraction Process ◽  
Refining Process ◽  
Anode Slime ◽  
Electrolytic Refining ◽  
Precipitation Procedure ◽  
Tin Anode

Tin anode slime is a by-product of the tin electrolytic refining process. This study investigated a route to separate Sn, Sb, Bi, and Cu from tin anode slime after leaching with hydrochloric acid. In the solvent extraction process with tributyl phosphate, Sb and Sn were extracted into the organic phase. Bi and Cu were unextracted and remained in the liquid phase. In the stripping experiment, Sb and Sn were stripped and separated with HCl and HNO3. Bi and Cu in the aqueous phase were also separated with chemical precipitation procedure by controlling pH value. The purities of Sn, Sb, Cu solution and the Bi-containing solid were 96.25%, 83.65%, 97.51%, and 92.1%. The recovery rates of Sn, Sb, Cu, and Bi were 76.2%, 67.1%, and 96.2% and 92.4%.

Separation of Heavy Metal Ions from the Solution Obtained by Leaching Low-Grade Pyrolusite with Pyrite and H2SO4

2013 ◽  
Vol 773 ◽  
pp. 283-288
Author(s):  
Xing Zou ◽  
Xiang Quan Chen ◽  
Hai Chao Xie ◽  
Xiao Dan Qiu
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Separation Efficiency ◽  
Ph Value ◽  
Sulfate Solution ◽  
Ion Concentration ◽  
Manganese Sulfate ◽  
Low Grade ◽  
High Concentration

The manganese sulfate solution leached from low-grade pyrolusite with pyrite and H2SO4 contains heavy metal ions of high concentration, influencing the quality of the final products of manganese compounds and causing manganese ions not to be electrolyzed. The present study was focused on the separation of Co, Ni and Zn ions from the leached solution with BaS. By controlling the pH value at 5.0-6.5, temperature at 50-60°C, reaction time at 15 min and mixing velocity at 78 rpm, the heavy metal ions could be separated effectively. Under the above optimized conditions, the ion concentration of Co, Ni, and Zn in the solution was reduced to 0.06 mg.L-1, 0.27mg.L-1 and 0.01mg.L-1, and the separation efficiency was 99.72%, 99.18% and 99.9% respectively. The obtained pure solution meets the demands of manganese electrowinning.

Preparation and Microanalysis Study of Nano-Hap/Cs-Chs Composites Materials

2012 ◽  
Vol 581-582 ◽  
pp. 463-466 ◽  
Author(s):  
Man De Qiu ◽  
Xiao Yan Wang ◽  
Yong Qing Zhai ◽  
Zi Hua Yao
Keyword(s):  
Chondroitin Sulfate ◽  
Organic Phase ◽  
Nano Particles ◽  
Precipitation Method ◽  
Composites Materials ◽  
Before And After ◽  
Calcium And Phosphorus ◽  
Co Precipitation

Nano-hydroxyapatite/chitosan-chondroitin sulfate composites materials with different weight ratios were prepared through liquid co-precipitation method. The nano-Hap、Hap/Cs and Hap/Cs-Chs composites materials under the same conditions preparation materials were researched By XRD, SEM and EDS respectively. The results show that nano-Hap particles with poorly crystallinity, the size is about 20nm, nano-Hap particles are spherical in sHape and dispersed uniformly, combined with relatively loose between particles, the small nano-particles aggregate into larger particles when the Hap composite with the Cs and Chs, nano-Hap were dispersed uniformly in the organic phase Cs and Chs, Hap particles have the trend to grow large in composites materials,crystal become more perfect, combination become relatively dense between particles, The composites materials were annealed at 700°C,Hap crystal particles become more perfect clear and larger with relatively loose between particles.EDS analysis showed that the compound before and after annealing of the material ratio of calcium had no influence, material does not contain any impurities,The ratio of calcium and phosphorus is about 1.75:1,Hap belonging to the type of calcium-rich

Formulation and Stability Test of Lip Cream Preparation of Kenop Flower Ethanol Extract (Gomphrena globosa L.)

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Mevi Irianti Tonapa ◽  
Rani Dewi Pratiwi ◽  
Elsye Gunawan
Keyword(s):  
Ph Value ◽  
Ethanol Extract ◽  
Stability Test ◽  
Gomphrena Globosa ◽  
Homogeneous Composition ◽  
Semi Solid ◽  
The Stability ◽  
Ph Range ◽  
Average Dispersion ◽  
Brown Color

Kenop Flower (Gomphrena globosa L.) is used in the manufacture of lip cream because contains betacyanin pigments that function as color pigments. This study aims to determine the physical quality and stability of the lip cream preparation of the ethanol extract of kenop flower (Gomphrena globosa L.). This research was conducted experimentally, including the manufacture of lip cream formulations with ethanol extract of kenop flower (Gomphrena globosa L.) with a concentration of 10%. The results of the physical examination test for lip cream preparations for all preparations have a distinctive vanilla aroma with a semi-solid texture, F0 has ivory white color and F1-F3 has a brown color. The preparations had a homogeneous composition, average pH 6-7, had good greasing power, 5.0-5.8 average dispersion and 60.33-66.67 seconds average adhesion. The stability test carried out on day 28 found that all preparations were stable, had a distinctive vanilla aroma with a semi-solid texture, F0 had ivory white color and F1-F3 had a brown color. The preparation has a homogeneous composition; the average pH is 6-7. Where the lip cream formulas F1 and F3 decreased the pH value on the 28th day from 7 to 6 but tended to be stable and in the pH range that matched the lip pH. And there is no phase separation in all formulas.

SIGNIFICANT EFFECT OF PH ON PHOTOCATALYTIC DEGRADATION OF ORGANIC POLLUTANTS USING SEMICONDUCTOR CATALYSTS

2016 ◽  
Vol 78 (8-3) ◽  
Author(s):  
Nur Farhana Jaafar ◽  
Aishah Abdul Jalil ◽  
Sugeng Triwahyono ◽  
Adnan Ripin ◽  
Mohamad Wijayanuddin Ali
Keyword(s):  
Carbon Dioxide ◽  
Methyl Orange ◽  
Physicochemical Properties ◽  
Photocatalytic Degradation ◽  
Organic Pollutants ◽  
Ph Value ◽  
Effect Of Ph ◽  
Electrolysis Method ◽  
Ph Range ◽  
Positively Charged

Photocatalytic is one of the inexpensive and non-toxic techniques for degradation of organic pollutants into harmless substances such as water and carbon dioxide. In this study, simple electrolysis method was used in preparation of Ag/TiO2 and α-Fe2O3/HY catalysts. The physicochemical properties of the catalysts were studied using XRD, FTIR, FESEM-EDX and surface area analysis. The pH of solution plays an important role in the photocatalytic degradation of organic pollutants which influences the surface-charge properties of the catalysts. Ag/TiO2 and α-Fe2O3/HY were used as catalyst on degradation of 2-chlorophenol (2-CP) and methyl orange (MO), respectively. The effect of pH on degradation of 2-CP and MO were investigated over a pH range from 2 to 9. Higher degradation of 2-CP and MO were obtained at pH 5 (74%) and pH 2 (80%), respectively. This finding might be explained by the amphoteric performance of the catalyst using point zero charge (pHZPC). The pHZPC for Ag/TiO2 and α-Fe2O3/HY was found to be at pH 6.3 and pH 7.2, respectively. Hence, the activities of the catalysts may have been affected by the existence of a strong electrostatic field between the positively charged catalysts surface and negatively charged 2-CP and MO caused a pH value lower than their pHZPC give greater degradation.

Controlled Synthesis of Different Morphologies of SrWO4 Crystals via a Surfactant-Assisted Hydrothermal Precipitation Method

2013 ◽  
Vol 785-786 ◽  
pp. 449-454
Author(s):  
Yan Zhao ◽  
Chun Yan Wu ◽  
Dan Qin ◽  
Xin Lai ◽  
Si Wu ◽  
...  
Keyword(s):  
Ph Value ◽  
Precipitation Method ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Experimental Parameters ◽  
Infrared Spectrometer ◽  
Luminescent Spectra ◽  
Hydrothermal Precipitation ◽  
Surfactant Assisted

SrWO4 octahedrons, flowers, bundles, ellipsoids and dendrites had been successfully synthesized via surfactant-assisted method. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), photo-luminescent spectra techniques (PL) and fourier transrform infrared spectrometer (FTIR). By through various comparison experiments, it can be found that some related experimental parameters including the reagent concentration, [Sr2+]/[WO42-] molar ratio (R), aging temperature and the pH value had great influences on morphology of the products.

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