Sequential extraction of vanadium and chromium from chromium-bearing vanadium slag through two-stage soda roasting-water leaching

2018 ◽  
Vol 115 (6) ◽  
pp. 607
Author(s):  
Helin Fan ◽  
Huamei Duan ◽  
Wenjie He ◽  
Dengfu Chen ◽  
Tao Liu ◽  
...  
Keyword(s):  
Sequential Extraction ◽  
Extraction Process ◽  
Water Soluble ◽  
Leaching Rate ◽  
Vanadium Slag ◽  
X Ray Diffraction ◽  
Water Leaching ◽  
Two Stage ◽  
Experimental Conditions ◽  
Roasting Process

The sequential extraction of vanadium and chromium from the chromium-bearing vanadium slag through two-stage soda roasting-water leaching was proposed. The precipitation order and thermodynamic stability of Cr-spinel and V-spinel were thoroughly calculated with FactSage 6.3 software. The mechanism of the sequential extraction process is further determined by X-ray diffraction (XRD). Thermodynamic calculations show that the precipitation order of main phases in the chromium-bearing vanadium slag is as follows: Cr-spinel → V-spinel → Fe-olivine, while the priority of the reaction between main phases with Na2CO3 follows the order of Fe-olivine → V-spinel → Cr-spinel. XRD results reveal that the vanadium-bearing phase in roasted slag is water-soluble NaVO3, while the chromium-bearing phase in roasted slag is Cr-spinel ((Mn, Fe) Cr2O4) and solid solutions ((Fe0.6Cr0.4)2 O3) with the soda amount of 21% and temperature of 800 °C. The different evolution route of vanadium-bearing phase and chromium-bearing phase during the roasting process ensures preferential extraction of vanadium from the chromium-bearing vanadium slag. The leaching rates of vanadium and chromium reach 89.36% and 4.91% with optimized experimental conditions. The high leaching rate of vanadium and low leaching rate of chromium show good results of preferential extraction of vanadium from the chromium-bearing vanadium slag.

Effective Extraction of Vanadium and Chromium from High Chromium Content Vanadium Slag by Sodium Roasting and Water Leaching

2016 ◽  
Vol 863 ◽  
pp. 144-148 ◽  
Author(s):  
Ming Li ◽  
Liang Xiao ◽  
Jing Jing Liu ◽  
Zhi Xin Shi ◽  
Zi Bi Fu ◽  
...  
Keyword(s):  
Chromium Content ◽  
Leaching Rate ◽  
Vanadium Slag ◽  
Water Leaching ◽  
Sodium Salts ◽  
High Chromium ◽  
Effective Factor ◽  
Roasting Process ◽  
Roasting Temperature ◽  
Roasting Time

The extraction of vanadium and chromium from high chromium content vanadium slag by salt roasting and water leaching process has been investigated, which uses mixed sodium salts (Na2CO3 and NaOH) as additive agent in roasting process. The mineralogical morphology was prospected by TG-DSC, XRD, SEM and EDS. The oxidation of slag and transversion of V/Cr-containing phase and sodium salts have been discussed. It has been demonstrated that the presence of NaOH contributes to decompose spinel and olivine phases, which is beneficial to reduce the roasting temperature and elevate V, Cr leaching ratio. The roasting parameters have been studied as a function of roasting temperature, roasting time and ratio of alkali, in which the roasting temperature is the most effective factor on the leaching rate of vanadium and chromium. Under the optimum condition, the leaching rates of V and Cr reached 95.8% and 97.6%, respectively.

scholarly journals Vanadium Extraction from Korean Vanadiferous Titanomagnetite Ore Using Alkali Roasting: Evaluation of Optimal Conditions and Leaching Rate

2021 ◽  
Author(s):  
Youngjae kim ◽  
Junsoo Yoo ◽  
Hyunsik Park ◽  
Ho-seok Jeon ◽  
Yosep Han
Keyword(s):  
Thermal Treatment ◽  
Treatment Time ◽  
Characteristic Temperature ◽  
Extraction Process ◽  
Leaching Rate ◽  
X Ray Diffraction ◽  
Water Leaching ◽  
Calculation Results ◽  
Roasting Temperature ◽  
Leaching Efficiency

Abstract The extraction process of vanadium from vanadiferous titanomagnetite ore deposited in Korea was investigated by combining alkali roasting and water leaching processes. The effect of Na2CO3 addition on the efficiency with which the vanadium could be leached was investigated along with an X-ray diffraction analysis. When more than 30-wt% Na2CO3 was added at 1273 K, a vanadium leaching efficiency of approximately 70% was achieved. The minimum alkali-roasting temperature was determined to be 1273 K with the addition of 30-wt% Na2CO3. Thermodynamic calculations revealed that the formation of the liquidus phase of Na2CO3 enhanced the reaction between the vanadium in the concentrate and sodium, resulting in a higher leaching efficiency for vanadium being attained. The thermodynamic calculation results were indirectly supported by the characteristic temperature determination through hot-stage microscope analysis. After 30 min of thermal treatment, a leaching efficiency for vanadium of 75% was achieved, which remained constant as the thermal treatment time was increased. Finally, the effects of the leaching time and temperature on the efficiency with which vanadium and other impurities, namely, aluminum, silicon, and sodium, could be leached was analyzed by varying the leaching time. A higher leaching efficiency was attained at higher temperatures. The leaching rate of vanadium decreased considerably after 10–20 min and subsequently remained almost constant.

scholarly journals Effects of sodium roasting on the leaching rate of boron-bearing tailings and its mechanism analysis

2018 ◽  
Vol 5 (8) ◽  
pp. 172342
Author(s):  
Chengxi Zou ◽  
Zhenyu Tang ◽  
Wei Xie ◽  
Hanguang Fu ◽  
Jiacai Kuang ◽  
...  
Keyword(s):  
Scientific Basis ◽  
Raw Material ◽  
Sodium Borate ◽  
Mechanism Analysis ◽  
Leaching Rate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Roasting Process ◽  
Roasting Temperature ◽  
Theoretical Amount

The study reported was intended to improve the leaching rate of boron-bearing tailings, using a method of sodium roasting that uses boron-bearing tailings as the raw material and Na 2 CO 3 as the sodium agent. The effects of the roasting temperature and Na 2 CO 3 amount on the leaching rate of boron-bearing tailings are mainly evaluated. The morphology and composition of the samples after sodium roasting are analysed by scanning electron microscopy and X-ray diffraction. The results show that sodium roasting can significantly improve the leaching rate of boron-bearing tailings. Under the optimal conditions where roasting temperature is 950°C, Na 2 CO 3 amount is five times the theoretical amount and roasting time is 2 h, the leaching rate of boron-bearing tailings is up to 86.78%. Based on the analysis of the characterization results and the mechanism analysis of the sodium roasting process, the main reason for the increase of leaching rate is the reaction between Na 2 O produced by the decomposition of Na 2 CO 3 and the boron in boron-bearing tailings resulting in soluble sodium borate. The results provide a scientific basis for the efficient comprehensive use of boron-bearing tailings.

scholarly journals Preparation of multifunctional nanocomposites Fe3O4@SiO2–EDTA and its adsorption of heavy metal ions in water solution

2020 ◽  
Vol 81 (1) ◽  
pp. 170-177 ◽  
Author(s):  
Tao Gong ◽  
Yongbai Tang
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Magnetic Materials ◽  
Heavy Metal Ions ◽  
Water Solution ◽  
Water Soluble ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Good Tolerance ◽  
Multifunctional Nanocomposites

Abstract Novel magnetic Fe3O4@SiO2-ethylenediamine tetraacetic acid (adsorbent) CMS–COOH-modified magnetic materials, CMS was prepared by surface modification of amino-functionalized Fe3O4@SiO2 (-NH2-modified magnetic materials, NMS) with EDTA using water-soluble carbodiimide as the cross-linker in deionized water solution. The phase structure, infrared spectra, thermal analysis and magnetic properties of were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, thermogravimetric analysis, and vibrating sample magnetometry and its properties for removal of heavy metal ions under varied experimental conditions were also investigated. The results revealed that CMS had good tolerance to low pH and exhibited good removal efficiency for the metal ions. The maximum adsorption capacities of CMS were found to be 0.11 mmol g−1 for Cu(II) at pH5.0 (30 °C) and 0.14 mmol g−1 for Pb(II) ions at pH2.0 (30 °C).

scholarly journals Sono-extraction as a pretreatment approach for the screening evaluation of element mobility of sediment samples

2013 ◽  
Vol 11 (7) ◽  
pp. 1201-1212 ◽  
Author(s):  
Jana Blašková ◽  
Viera Vojteková ◽  
Jarmila Nováková ◽  
Daniela Mackových ◽  
Yaroslav Bazeľ ◽  
...  
Keyword(s):  
Sequential Extraction ◽  
Operating Time ◽  
Single Step ◽  
Water Soluble ◽  
Rapid Screening ◽  
Acid Mixture ◽  
Element Mobility ◽  
Water Leaching ◽  
Time Saving ◽  
Element Contents

AbstractApplication of economically important and time saving pretreatment for the screening element mobility evaluation of contaminated sediments is presented. Ultrasonically-assisted single-step extraction (USAE) was carried out by EDTA solution. The extraction time of USAE was optimized and obtained results were compared with results estimated by conventional (EDTA extraction) and by sequential extraction (modified BCR protocol). The original three step BCR protocol was modified by addition of the first step (water leaching) and the fifth step, total digestion of sediment residue (acid mixture with HF). Zn, Cu and Pb have been determined in extracts by ICP-OES. Good conformity of the ultrasonically-extracted element contents and sum of contents, extracted during first three steps (water-soluble, acid-extractable, reducible — i.e., the most mobile fractions) of sequential extraction, was found. The sono-extraction reduced operating time of the first three steps of sequential extraction from 48 h to 15 min. Thus, USAE can serve as a rapid screening assessment of the mobile and potentially mobile element portions in sediments and other similar solid state environmental media. Analytical quality control was realized by comparison of the sums of element contents obtained at individual (five) extraction steps. Total element contents were also determined by an independent method (XRF).

Study of Sulphatizing Roasting Process Using Iron Sulphates for the Treatment of Zinc Leach Residue

2020 ◽  
Vol 989 ◽  
pp. 448-455
Author(s):  
Pavel Grudinsky ◽  
Ekaterina Podjelnikova ◽  
Valery Dyubanov
Keyword(s):  
High Efficiency ◽  
Water Soluble ◽  
Leach Residue ◽  
Water Leaching ◽  
Zinc Plant ◽  
Roasting Process ◽  
Temperature Ranges ◽  
Iron Sulphate ◽  
Iron Sulphates ◽  
Soluble Sulphate

The paper presents the results of the investigation of zinc leach residue (ZLR) processing by sulphatizing roasting with iron sulphates FeSO4 and Fe2(SO4)3 followed by water leaching. The elemental and phase compositions of ZLR of JSC "Chelyabinsk Zinc Plant" were studied. Based on the thermodynamic calculations using HSC Chemistry 9.9 software, the temperature ranges of the sulphatizing roasting and the required amounts of iron sulphate additives for the sulphation of zinc and copper were determined. Subsequent experiments showed that recovery rates of zinc and copper reached 99.5% and 89.1% respectively, while iron remained in the leached residue. The results have indicated a high efficiency of sulphatizing roasting to transform zinc and copper contained in ZLR from ferrite to water-soluble sulphate.

Aqueous Processing of L-Glutathione Capped ZnO Quantum dots for Potential Biomedical Applications

2015 ◽  
Vol 1797 ◽  
Author(s):  
Raquel Feliciano-Crespo ◽  
José A Rodriguez ◽  
Myrna Reyes-Blas ◽  
Chuan-Jian Zhong ◽  
Oscar Perales-Perez
Keyword(s):  
Zno Nanoparticles ◽  
Cellular Membrane ◽  
Water Soluble ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Aqueous Synthesis ◽  
E Coli ◽  
Molar Ratios ◽  
Transmission Electron ◽  
Ft Ir

ABSTRACTMedical research has demonstrated the importance of the utilization of stable, fluorescent nanoprobes. The present work addresses the applicability of biocompatible and fluorescent ZnO nanoparticles as probes for detection of pathogens with the aim of achieving extremely low detection limits. For this purpose, ZnO surface must be functionalized for its subsequent interaction with bacterial cellular membrane (coupling), which will allow the corresponding detection and quantification. Herein we will discuss the aqueous synthesis of stable, water soluble and biologically compatible ZnO nanoparticles (NPss) capped with L-glutathione (GSH). The understanding of the interactions between GSH molecules and surface atoms in ZnO QDs became critical to foster the applicability of this nanomaterial in the biomedical and bioengineering fields. In this regard, the GSH/ZnO molar ratios, reaction temperature (40°C and 60°C), time and pH (6-9) became crucial factors to attain suitable tuning of the QDs properties. ZnO/GSH synthesized QDs were characterized by Transmission Electron Microscopy, X-Ray Diffraction, FT-IR, UV-Vis and photoluminescence (PL) spectroscopy. The QDs shape was spherical with a particle size between 80-100nm. The synthesis of ZnO/GSH under different experimental conditions and the corresponding coupling with E. Coli species, are presented and discussed.

Molecularly Imprinted Sensor for Ascorbic Acid Based on Gold Nanoparticles and Multiwalled Carbon Nanotubes

2020 ◽  
Vol 16 (7) ◽  
pp. 905-913
Author(s):  
Youyuan Peng ◽  
Qingshan Miao
Keyword(s):  
Carbon Nanotubes ◽  
Gold Nanoparticles ◽  
Ascorbic Acid ◽  
Multiwalled Carbon Nanotubes ◽  
Ph Value ◽  
Biological Fluids ◽  
Water Soluble ◽  
Multiwalled Carbon ◽  
Experimental Conditions ◽  
Molecularly Imprinted

Background: L-Ascorbic acid (AA) is a kind of water soluble vitamin, which is mainly present in fruits, vegetables and biological fluids. As a low cost antioxidant and effective scavenger of free radicals, AA may help to prevent diseases such as cancer and Parkinson’s disease. Owing to its role in the biological metabolism, AA has also been utilized for the therapy of mental illness, common cold and for improving the immunity. Therefore, it is very necessary and urgent to develop a simple, rapid and selective strategy for the detection of AA in various samples. Methods: The molecularly imprinted poly(o-phenylenediamine) (PoPD) film was prepared for the analysis of L-ascorbic acid (AA) on gold nanoparticles (AuNPs) - multiwalled carbon nanotubes (MWCNTs) modified glass carbon electrode (GCE) by electropolymerization of o-phenylenediamine (oPD) and AA. Experimental parameters including pH value of running buffer and scan rates were optimized. Scanning electron microscope (SEM), fourier-transform infrared (FTIR) spectra, cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were utilized for the characterization of the imprinted polymer film. Results: Under the selected experimental conditions, the DPV peak currents of AA exhibit two distinct linear responses ranging from 0.01 to 2 μmol L-1 and 2 to 100 μmol L-1 towards the concentrations of AA, and the detection limit was 2 nmol L-1 (S/N=3). Conclusion: The proposed electrochemical sensor possesses excellent selectivity for AA, along with good reproducibility and stability. The results obtained from the analysis of AA in real samples demonstrated the applicability of the proposed sensor to practical analysis.

scholarly journals Zeolite NaP1 Functionalization for the Sorption of Metal Complexes with Biodegradable N-(1,2-dicarboxyethyl)-D,L-aspartic Acid

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2518
Author(s):  
Dorota Kołodyńska ◽  
Yongming Ju ◽  
Małgorzata Franus ◽  
Wojciech Franus
Keyword(s):  
Experimental Data ◽  
Aspartic Acid ◽  
Ph Value ◽  
Complexing Agents ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Modified Zeolite ◽  
X Ray ◽  
Slow Release Fertilizers ◽  
Pseudo Second Order

The possibility of application of chitosan-modified zeolite as sorbent for Cu(II), Zn(II), Mn(II), and Fe(III) ions and their mixtures in the presence of N-(1,2-dicarboxyethyl)-D,L-aspartic acid, IDHA) under different experimental conditions were investigated. Chitosan-modified zeolite belongs to the group of biodegradable complexing agents used in fertilizer production. NaP1CS as a carrier forms a barrier to the spontaneous release of the fertilizer into soil. The obtained materials were characterized by Fourier transform infrared spectroscopy (FTIR); surface area determination (ASAP); scanning electron microscopy (SEM-EDS); X-ray fluorescence (XRF); X-ray diffraction (XRD); and carbon, hydrogen, and nitrogen (CHN), as well as thermogravimetric (TGA) methods. The concentrations of Cu(II), Zn(II), Mn(II), and Fe(III) complexes with IDHA varied from 5–20 mg/dm3 for Cu(II), 10–40 mg/dm3 for Fe(III), 20–80 mg/dm3 for Mn(II), and 10–40 mg/dm3 for Zn(II), respectively; pH value (3–6), time (1–120 min), and temperature (293–333 K) on the sorption efficiency were tested. The Langmuir, Freundlich, Dubinin–Radushkevich, and Temkin adsorption models were applied to describe experimental data. The pH 5 proved to be appropriate for adsorption. The pseudo-second order and Langmuir models were consistent with the experimental data. The thermodynamic parameters indicate that adsorption is spontaneous and endothermic. The highest desorption percentage was achieved using the HCl solution, therefore, proving that method can be used to design slow-release fertilizers.

scholarly journals Selective growth of Ti3+/TiO2/CNT and Ti3+/TiO2/C nanocomposite for enhanced visible-light utilization to degrade organic pollutants by lowering TiO2-bandgap

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jeasmin Akter ◽  
Md. Abu Hanif ◽  
Md. Akherul Islam ◽  
Kamal Prasad Sapkota ◽  
Jae Ryang Hahn
Keyword(s):  
Visible Light ◽  
Structural Integrity ◽  
Carbon Layer ◽  
Wide Bandgap ◽  
Blue Dye ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Excellent Photocatalytic Activity ◽  
Convenient Route ◽  
Walled Carbon Nanotubes

AbstractA convenient route was developed for the selective preparation of two stable nanocomposites, Ti3+/TiO2/CNT (labeled as TTOC-1 and TTOC-3) and Ti3+/TiO2/carbon layer (labeled as TTOC-2), from the same precursor by varying the amount of single-walled carbon nanotubes used in the synthesis. TiO2 is an effective photocatalyst; however, its wide bandgap limits its usefulness to the UV region. As a solution to this problem, our prepared nanocomposites exhibit a small bandgap and wide visible-light (VL) absorption because of the introduction of carbonaceous species and Ti3+ vacancies. The photocatalytic efficiency of the nanocomposites was examined via the degradation of methylene blue dye under VL. Excellent photocatalytic activity of 83%, 98%, and 93% was observed for TTOC-1, TTOC-2, and TTOC-3 nanocomposites within 25 min. In addition, the photocatalytic degradation efficiency of TTOC-2 toward methyl orange, phenol, rhodamine B, and congo red was 28%, 69%, 71%, and 91%, respectively, under similar experimental conditions after 25 min. Higher reusability and structural integrity of the as-synthesized photocatalyst were confirmed within five consecutive runs by photocatalytic test and X-ray diffraction analysis, respectively. The resulting nanocomposites provide new insights into the development of VL-active and stable photocatalysts with high efficiencies.

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