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asadollahzadeh--mehdi
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Experimental Study of Molybdenum Extraction Process in an Oldshue-rushton Extraction Column
, M.Sc. Thesis Sharif University of Technology ; Outokesh, Mohammad (Supervisor) ; Torab- Mostaedi, Mesam (Supervisor) ; Asadollahzadeh, Mehdi (Co-Supervisor)
Abstract
Extraction and separetion of molybdenum is important because of its application in different industries. Since molybdenum resources are finite and low-grade, hydrometallurgical methods can be used to extract molybdenum. Solvent extraction of rare metals one of the important processes of hydrometallurgy.In the first of research, molybdenum solvent extraction from sulfate msoloution was investigated in batch and semi-industrial scale. In the laboratory scale, molybdenum solvent extraction from aqueous solution was investigated by using of D2EHPA, Cyanex272 and TBP. The effects of various parameters such as extractrant concentration, synergistic enhancement factor for mixture of extractants,...
Investigation of Operating Parameters for Thorium Adsorption from Wastewater by Using of Radiated Grafting Polymeric Adsorbents in Packed Bed Column
, M.Sc. Thesis Sharif University of Technology ; Outokesh, Mohamad (Supervisor) ; Torab Mostaedi, Meysam (Supervisor) ; Asadollahzadeh, Mehdi (Co-Supervisor) ; Torkaman, Rezvan (Co-Supervisor)
Abstract
Today, the pollution of heavy metals in wastewater and surface waters, which is a global environmental problem, has increased with the expansion of various industrial activities. Heavy metals cause serious health problems due to their accumulation in human and animal tissues. Thorium, is a radioactive element with an atomic number of 90 that is widely used in the optics, aerospace, metallurgy and chemical industries, in the manufacture of high-strength alloys, in UV photocells, and especially in the nuclear industry. The primary sources of radioactive wastewater include nuclear power plants, nuclear energy industry research centers, medical institutions, industrial production, universities,...
Synthesis and Characterization of Polymer Nanofibers Modified by Using of Radiated Grafting for Adsorption of Molybdenum Ions from Aqueous Solution
, M.Sc. Thesis Sharif University of Technology ; Outokesh, Mohammad (Supervisor) ; Asadollahzadeh, Mehdi (Supervisor) ; Torkaman, Rezvan (Co-Supervisor) ; Torab Mostaedi, Meysam (Co-Supervisor)
Abstract
Molybdenum is one of the important elements of the intermediary metal with atomic number 42, which is used in various industries, but among the important uses of this metal in the nuclear industry, we can mention the presence of this element in the production of yellow cake as an impurity and also as a precursor for the production of radiopharmaceuticals. It is one of the impurities that remain in all stages of yellow cake production along with uranium, and the high presence of this element causes the centrifuges to become unbalanced during the injection of "U" "F" _"6" gas, and on the other hand, technetium, the main ingredient in the production of radiopharmaceuticals, It comes from the...
Experimental modeling and uncertainty analysis of dispersed phase holdup at flooding in a pulsed disc-doughnut column, case study: Response surface methodology and Monte-Carlo simulation
, Article Progress in Nuclear Energy ; Volume 141 , 2021 ; 01491970 (ISSN) ; Ghaemi, A ; Hemmati, A ; Asadollahzadeh, M ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
This study aims to investigate, optimize, and simulate the dispersed phase holdup at flooding conditions for the standard physical systems in a pulsed extraction column with the disc-doughnut configuration. The interaction impacts for operational parameters (pulse intensity and organic and aqueous phase velocities) and interfacial tension (systems type) were examined using the response surface approach. A novel correlation for the dependent parameter, namely holdup at flooding based on the quadratic model, was developed with the central composition design methodology. A desirable agreement between actual data and calculated data from the proposed model was observed because of the high...
Extraction of molybdenum (VI) and vanadium (V) from nitrate solutions using coupling of acid and solvating extractants
, Article International Journal of Engineering, Transactions A: Basics ; Volume 32, Issue 10 , 2019 , Pages 1366-1371 ; 17281431 (ISSN) ; Torab Mostaedi, M ; Outokesh, M ; Asadollahzadeh, M ; Sharif University of Technology
Materials and Energy Research Center
2019
Abstract
In this study, solvent extraction method has been utilized for separation of molybdenum and vanadium from nitrate solution by utilizing coupling of acid and solvating extractants (D2EHPA and TBP extractants). The outcomes demonstrated that synergistic solvent extraction improves stability of formatted complexes for transfer to the organic phase. The main parameters such as pH value, concentration of extractants, NH4OH concentration as the stripping agent and contact time were optimized at 0.4, 15% (v/v) D2EHPA, 10% (v/v) TBP, 2 M and 30 min, respectively. The maximum separation factor of 24.84 was obtained with a new synergistic mixture of D2EHPA and TBP diluted with kerosene. According to...
Mass transfer coefficients of extracting Mo (VI) and W (VI) in a stirred tank by solvent extraction using mixture of Cyanex272 and D2EHPA
, Article Separation Science and Technology (Philadelphia) ; 2019 ; 01496395 (ISSN) ; Torab Mostaedi, M ; Outokesh, M ; Asadollahzadeh, M ; Sharif University of Technology
Taylor and Francis Inc
2019
Abstract
In this study, the mass transfer evaluation of an agitated liquid-liquid system for the extraction of molybdenum and tungsten from aqueous sulfate solution was investigated. It was found from batch experiments for separation of molybdenum from tungsten that the initial aqueous pH, Cyanex272 and D2EHPA concentration, contact time, dispersed phase volume fraction and impeller speed were optimized at 1.3, 0.07 M, 0.29 M, 15 min, 0.09 and 280 rpm, respectively. The results indicate that a suitable composition for stripping is 1.5 M NH4OH and 0.6 M NH4F. Furthermore, a modified correlation based on dimensionless numbers was derived for the prediction of continuous phase mass transfer in the...
Mass transfer coefficients of extracting Mo (VI) and W (VI) in a stirred tank by solvent extraction using mixture of Cyanex272 and D2EHPA
, Article Separation Science and Technology (Philadelphia) ; Volume 55, Issue 17 , 2020 , Pages 3140-3150 ; Torab Mostaedi, M ; Outokesh, M ; Asadollahzadeh, M ; Sharif University of Technology
Bellwether Publishing, Ltd
2020
Abstract
In this study, the mass transfer evaluation of an agitated liquid-liquid system for the extraction of molybdenum and tungsten from aqueous sulfate solution was investigated. It was found from batch experiments for separation of molybdenum from tungsten that the initial aqueous pH, Cyanex272 and D2EHPA concentration, contact time, dispersed phase volume fraction and impeller speed were optimized at 1.3, 0.07 M, 0.29 M, 15 min, 0.09 and 280 rpm, respectively. The results indicate that a suitable composition for stripping is 1.5 M NH4OH and 0.6 M NH4F. Furthermore, a modified correlation based on dimensionless numbers was derived for the prediction of continuous phase mass transfer in the...
Revealing mass transfer and hydrodynamic effects in a PRDC column by using the integration of extraction and separation for molybdenum and tungsten ions from aqueous solution
, Article Chemical Papers ; Volume 74, Issue 12 , 2020 , Pages 4295-4313 ; Torkaman, R ; Torab Mostaedi, M ; Asadollahzadeh, M ; Sharif University of Technology
Springer
2020
Abstract
The present work is performed to assess the hydrodynamic parameters and mass transfer coefficients in a PRDC column for the chemical reaction systems. By considering the selective extraction of molybdenum from tungsten, the extraction parameters and synergistic enhancement factor were interpreted at the batch experiments. In the column experiments, the impacts of operating conditions such as the agitation rate, inlet solvent phase velocity as well as inlet aqueous phase velocity were studied on the drop behavior, overall mass transfer coefficients, and extraction efficiencies. The modified correlations by using relationship of dimensionless numbers were illustrated to estimate the...
Mass transfer evaluation in a multi-impeller extractor for reactive Mo (VI) extraction from aqueous Sulphate solution by utilizing coupling of acid and solvating Extractants
, Article Heat and Mass Transfer/Waerme- und Stoffuebertragung ; Volume 56, Issue 6 , 2020 , Pages 1995-2006 ; Torab Mostaedi, M ; Outokesh, M ; Asadollahzadeh, M ; Sharif University of Technology
Springer
2020
Abstract
In this study, mass transfer experimental data from the present column with 70 cm active column length and 11.3 cm internal diameter were interpreted for molybdenum extraction with a mixture of D2EHPA and TBP in terms of the axial diffusion model. The influence of extractants concentration and the initial aqueous pH have studied in the bench-scale experiments. The experimental finding demonstrated that the synergistic solvent extraction increases the constancy of the extracted complexes for transfer into the organic phase. The effect of operating parameters, including agitation speed and inlet phase velocities on the overall mass transfer coefficients under the chemical reaction system, is...
Exact hydrodynamic description of pilot plant Oldshue-Rushton contactor: a case study with the introduction of selenium and tellurium into reaction system
, Article International Journal of Environmental Analytical Chemistry ; 2020 ; Torkaman, R ; Torab Mostaedi, M ; Asadollahzadeh, M ; Sharif University of Technology
Taylor and Francis Ltd
2020
Abstract
In this paper, the hydrodynamic behaviour of the chemical reaction system (selenium, tellurium, and TBP) was interpreted in the Oldshue-Rushton extraction column. The optimum operating parameters for extracting the selenium and tellurium from chloride medium were carried out by using the batch experiments. The feed acidity of 5 molar and solvent phase with 20% (v/v) TBP in kerosene were optimised to examine the hydrodynamic parameters of the mentioned column. The impacts of operating variables such as rotor speed, inlet aqueous phase velocity, and inlet solvent phase velocity on the dispersed phase hold-up, mean drop size, slip velocity, drop size distribution, and extraction rate were...
Mass transfer studies in RDC column by the coupling effects of perforated structure and reactive extraction of Mo(VI) and W(VI) from sulfate solution
, Article International Communications in Heat and Mass Transfer ; Volume 118 , 2020 ; Torkaman, R ; Torab Mostaedi, M ; Asadollahzadeh, M ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Solvent extraction of molybdenum (VI) and tungsten (VI) by synergism of the mixture of D2EHPA and TBP were conducted in the RDC extractor with perforated structure. The initial aqueous pH, extractant concentration, ammonium hydroxide concentration as a stripping agent, and synergistic enhancement factor were optimized in the initial experiments before collecting column data. In the RDC column, the influence of agitation rate and inlet phase velocities were examined on the hydrodynamic velocities, mass transfer data, and distribution coefficients. The finding data indicated that the impact of agitation speed on the distribution coefficients of molybdenum and tungsten is considerable in...
The performance of pulsed scale-up column for permeable of selenium and tellurium ions to organic phase, case study: Disc and doughnut structure
, Article Chemical Engineering and Processing - Process Intensification ; Volume 157 , 2020 ; Torkaman, R ; Torab Mostaedi, M ; Asadollahzadeh, M ; Sharif University of Technology
Elsevier B.V
2020
Abstract
A research investigation of the overall mass transfer coefficients, holdup and mean drops of dispersed phase as well as slip and characteristic velocities were carried out in the pulsed scale-up column with disc and doughnut structure for extraction of tellurium and selenium from a hydrochloric acid medium with TBP extractant. The impact of operating conditions containing the pulse intensity, inlet aqueous and solvent phase velocities have been studied on the mass transfer rates, and the special column characteristic. By considering the reactive extraction situations, modified models were derived for predicting of holdup, d32, and slip velocity in this extractor. The axial diffusion model...
Direct extraction of Mo(VI) from sulfate solution by synergistic extractants in the rotation column
, Article Chinese Journal of Chemical Engineering ; Volume 28, Issue 2 , 2020 , Pages 445-455 ; Torab Mostaedi, M ; Outokesh, M ; Asadollahzadeh, M ; Sharif University of Technology
Chemical Industry Press
2020
Abstract
Direct extraction of molybdenum from sulfate solution with synergistic extractants (mixture of D2EHPA and TBP) was studied in the rotation column. The influence of extractant concentration and initial pH of aqueous phase was studied in the bench scale experiments. The outcomes demonstrated that the synergistic solvent extraction enhances the constancy of the extracted complexes for transfer into the organic phase. In the continuous experiments, the effect of different operating parameters such as speed of agitation, inlet solvent flow rate and inlet aqueous flow rate on the holdup, mean drop size, drop size distribution, slip and characteristic velocities and extraction percentage were...
Enhancing the vanadium extraction performance using synergistic mixtures of d2ehpa and tbp in rdc column with the perforated structure; case study: evaluation probability density functions
, Article Chemical Engineering and Processing - Process Intensification ; Volume 166 , 2021 ; 02552701 (ISSN) ; Torkaman, R ; Torab Mostaedi, M ; Asadollahzadeh, M ; Sharif University of Technology
Elsevier B.V
2021
Abstract
The reactive extraction behavior on the mean drop size and distribution for synergistic extraction of vanadium from sulfate medium with di-(2-ethylhexyl) phosphoric acid (D2EHPA) and its mixture with tributyl phosphate (TBP) in kerosene has been interpreted in the modified rotating disc contactor column. In batch experiments, the maximum extraction efficiency was obtained in the single extraction system with 0.29 molar D2EHPA at an equilibrium pH of 2, whereas the extraction percentage was significantly increased by adding 0.3 molar TBP into the same D2EHPA concentration due to the synergistic effect. The solvent extraction process has been optimized by applying the central composition...
Proficiency of tellurium extraction in pulsed disc and doughnut columns
, Article Separation Science and Technology (Philadelphia) ; Volume 56, Issue 18 , 2021 , Pages 3092-3105 ; 01496395 (ISSN) ; Torkaman, R ; Torab Mostaedi, M ; Asadollahzadeh, M ; Sharif University of Technology
Taylor and Francis Ltd
2021
Abstract
In this research, the separation of tellurium from selenium was studied from chloride solution by TBP extractant. In the batch experiments, the experimental findings indicated that the feed acidity, TBP concentration, and contact time were optimized to achieve the high separation factor. In continuous mode of pulsed disc and doughnut column, the impacts of operating parameters have been discussed on the distribution coefficients of selenium and tellurium, and mass transfer enhancement. A new model for predicting Koca was proposed in terms of holdup values, Sherwood, Reynolds, and Schmidt numbers, which has an acceptable agreement with the mass transfer data. © 2020 Taylor & Francis Group,...
Exact hydrodynamic description of pilot plant Oldshue-Rushton contactor: a case study with the introduction of selenium and tellurium into reaction system
, Article International Journal of Environmental Analytical Chemistry ; Volume 102, Issue 16 , 2022 , Pages 4191-4207 ; 03067319 (ISSN) ; Torkaman, R ; Torab Mostaedi, M ; Asadollahzadeh, M ; Sharif University of Technology
Taylor and Francis Ltd
2022
Abstract
In this paper, the hydrodynamic behaviour of the chemical reaction system (selenium, tellurium, and TBP) was interpreted in the Oldshue-Rushton extraction column. The optimum operating parameters for extracting the selenium and tellurium from chloride medium were carried out by using the batch experiments. The feed acidity of 5 molar and solvent phase with 20% (v/v) TBP in kerosene were optimised to examine the hydrodynamic parameters of the mentioned column. The impacts of operating variables such as rotor speed, inlet aqueous phase velocity, and inlet solvent phase velocity on the dispersed phase hold-up, mean drop size, slip velocity, drop size distribution, and extraction rate were...
Observational comparative study in Kühni and ORC agitated columns for the mechanism and performance of molybdenum extraction under various hydrodynamic conditions
, Article International Journal of Heat and Mass Transfer ; Volume 185 , 2022 ; 00179310 (ISSN) ; Torkaman, R ; Torab-Mostaedi, M ; Asadollahzadeh, M ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
The present work is expressed to interpret the hydrodynamic parameters of rotation extraction columns in the reactive and non-reactive systems. The solvent extraction technique has been utilized for optimizing the transportation of molybdenum ions to the organic phase in two agitated columns (ORC and Kühni columns). Dispersed phase volume fraction, average droplet diameter, slip velocity, size distribution, and ions permeability of the aqueous phase have been investigated in terms of changing the operational variables including the agitation rate, flow rate of the inlet dispersed and continuous phases, column geometry, and reaction conditions. By considering the reactive and non-reactive...
Reactive extraction of zinc ions in the Scheibel column; A case study by applying the mathematical modelling of mass transfer with forward mixing
, Article Chemical Engineering and Processing - Process Intensification ; Volume 169 , 2021 ; 02552701 (ISSN) ; Torkaman, R ; Saremi, M ; Torab Mostaedi, M ; Asadollahzadeh, M ; Sharif University of Technology
Elsevier B.V
2021
Abstract
An experimental and modeling study on the feasibility of the Scheibel extraction column is presented for heavy metal separation from chloride solution. In continuous experiments, the chemical reaction systems are considered zinc extraction by D2EHPA and stripping from the loaded organic phase by chloride solutions. The experimental results represent that the best extraction and stripping rates in the agitation speed of 155 rpm and the rate of inlet phases of 28 L/h are equal to 99.56% and 98.11%, respectively. The mass transfer modeling by applying the forward mixing is interpreted for solvent extraction systems in this column with the fitting technique. The calculated results from...
Experimental study and correlation for mass transfer coefficient in the pilot plant multistage column with the presence of molybdenum
, Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 41, Issue 2 , 2022 , Pages 544-554 ; 10219986 (ISSN) ; Torab Mostaedi, M ; Outokesh, M ; Torkaman, R ; Asadollahzadeh, M ; Sharif University of Technology
Iranian Institute of Research and Development in Chemical Industries
2022
Abstract
In the present work, multistage extraction column performance for reactive separation of molybdenum from the leach aqueous phase by using D2EHPA and TBP in kerosene was investigated by using the axial diffusion model. The variation of volumetric overall mass transfer coefficients based on continuous phases at various operating conditions was obtained. By considering the chemical reaction conditions, the experimental data indicate that the volumetric overall mass transfer coefficients increase with an enhancement in rotor speed and continuous and dispersed phase flow rates. According to the sensitivity analysis, the rotor speed and flow rate of the dispersed phase have more influence on...
Performance evaluation during extraction technique in modified rotating disc column: Experimental and mathematical modeling
, Article Chemical Engineering and Processing - Process Intensification ; Volume 171 , 2022 ; 02552701 (ISSN) ; Torkaman, R ; Torab Mostaedi, M ; Saremi, M ; Asadollahzadeh, M ; Sharif University of Technology
Elsevier B.V
2022
Abstract
In this survey, the reactive mass transfer data are determined for extraction technique in the modified rotating disc column. Mathematical models are investigated to compute the mass transfer coefficients of the dispersed phase. An increase in the dispersed phase holdup from 0.85 to 0.12 and a decrease in droplet diameter from 2.24 to 0.74 mm are observed with increasing rotation speed from 170 to 410 rpm in the optimized system. The experiments showed that the optimum transport efficiency in rotor speed of 410 rpm in this column is equal to 98.85% and 99.45% for extraction and stripping stages, respectively. The model's achievement is compared with the solvent extraction data and a...